Social distancing between personal belongings during the COVID-19 pandemic

Social distancing between personal belongings... | F1000Research "use strict";function _typeof(t){return(_typeof="function"==typeof Symbol&&"symbol"==typeof Symbol.iterator?function(t){return typeof t}:function(t){return t&&"function"==typeof Symbol&&t.constructor===Symbol&&t!==Symbol.prototype?"symbol":typeof t})(t)}!function(){var t=function(){var t,e,o=[],n=window,r=n;for(;r;){try{if(r.frames.__tcfapiLocator){t=r;break}}catch(t){}if(r===n.top)break;r=r.parent}t||(!function t(){var e=n.document,o=!!n.frames.__tcfapiLocator;if(!o)if(e.body){var r=e.createElement("iframe");r.style.cssText="display:none",r.name="__tcfapiLocator",e.body.appendChild(r)}else setTimeout(t,5);return!o}(),n.__tcfapi=function(){for(var t=arguments.length,n=new Array(t),r=0;r 3&&2===parseInt(n[1],10)&&"boolean"==typeof n[3]&&(e=n[3],"function"==typeof n[2]&&n[2]("set",!0)):"ping"===n[0]?"function"==typeof n[2]&&n[2]({gdprApplies:e,cmpLoaded:!1,cmpStatus:"stub"}):o.push(n)},n.addEventListener("message",(function(t){var e="string"==typeof t.data,o={};if(e)try{o=JSON.parse(t.data)}catch(t){}else o=t.data;var n="object"===_typeof(o)&&null!==o?o.__tcfapiCall:null;n&&window.__tcfapi(n.command,n.version,(function(o,r){var a={__tcfapiReturn:{returnValue:o,success:r,callId:n.callId}};t&&t.source&&t.source.postMessage&&t.source.postMessage(e?JSON.stringify(a):a,"*")}),n.parameter)}),!1))};"undefined"!=typeof module?module.exports=t:t()}(); dataLayer = dataLayer || []; // Standard GTM initialization - Google Consent Mode handles consent automatically (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start': new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0], j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src= 'https://www.googletagmanager.com/gtm.js?id='+i+dl+ '>m_auth=hzk0Vc3qFsQYhCrIoHz68A>m_preview=env-1>m_cookies_win=x';f.parentNode.insertBefore(j,f); })(window,document,'script','dataLayer','GTM-MWFK8L5J'); ;window.NREUM||(NREUM={});NREUM.init={distributed_tracing:{enabled:true},privacy:{cookies_enabled:true},ajax:{deny_list:["bam.nr-data.net"]}}; ;NREUM.loader_config={accountID:"438030",trustKey:"438030",agentID:"772317073",licenseKey:"97f8f67f26",applicationID:"772317073"} ;NREUM.info={beacon:"bam.nr-data.net",errorBeacon:"bam.nr-data.net",licenseKey:"97f8f67f26",applicationID:"772317073",sa:1} ;/*! For license information please see nr-loader-spa-1.236.0.min.js.LICENSE.txt */ (()=>{"use strict";var e,t,r={5763:(e,t,r)=>{r.d(t,{P_:()=>l,Mt:()=>g,C5:()=>s,DL:()=>v,OP:()=>T,lF:()=>D,Yu:()=>y,Dg:()=>h,CX:()=>c,GE:()=>b,sU:()=>_});var n=r(8632),i=r(9567);const o={beacon:n.ce.beacon,errorBeacon:n.ce.errorBeacon,licenseKey:void 0,applicationID:void 0,sa:void 0,queueTime:void 0,applicationTime:void 0,ttGuid:void 0,user:void 0,account:void 0,product:void 0,extra:void 0,jsAttributes:{},userAttributes:void 0,atts:void 0,transactionName:void 0,tNamePlain:void 0},a={};function s(e){if(!e)throw new Error("All info objects require an agent identifier!");if(!a[e])throw new Error("Info for ".concat(e," was never set"));return a[e]}function c(e,t){if(!e)throw new Error("All info objects require an agent identifier!");a[e]=(0,i.D)(t,o),(0,n.Qy)(e,a[e],"info")}var u=r(7056);const d=()=>{const e={blockSelector:"[data-nr-block]",maskInputOptions:{password:!0}};return{allow_bfcache:!0,privacy:{cookies_enabled:!0},ajax:{deny_list:void 0,enabled:!0,harvestTimeSeconds:10},distributed_tracing:{enabled:void 0,exclude_newrelic_header:void 0,cors_use_newrelic_header:void 0,cors_use_tracecontext_headers:void 0,allowed_origins:void 0},session:{domain:void 0,expiresMs:u.oD,inactiveMs:u.Hb},ssl:void 0,obfuscate:void 0,jserrors:{enabled:!0,harvestTimeSeconds:10},metrics:{enabled:!0},page_action:{enabled:!0,harvestTimeSeconds:30},page_view_event:{enabled:!0},page_view_timing:{enabled:!0,harvestTimeSeconds:30,long_task:!1},session_trace:{enabled:!0,harvestTimeSeconds:10},harvest:{tooManyRequestsDelay:60},session_replay:{enabled:!1,harvestTimeSeconds:60,sampleRate:.1,errorSampleRate:.1,maskTextSelector:"*",maskAllInputs:!0,get blockClass(){return"nr-block"},get ignoreClass(){return"nr-ignore"},get maskTextClass(){return"nr-mask"},get blockSelector(){return e.blockSelector},set blockSelector(t){e.blockSelector+=",".concat(t)},get maskInputOptions(){return e.maskInputOptions},set maskInputOptions(t){e.maskInputOptions={...t,password:!0}}},spa:{enabled:!0,harvestTimeSeconds:10}}},f={};function l(e){if(!e)throw new Error("All configuration objects require an agent identifier!");if(!f[e])throw new Error("Configuration for ".concat(e," was never set"));return f[e]}function h(e,t){if(!e)throw new Error("All configuration objects require an agent identifier!");f[e]=(0,i.D)(t,d()),(0,n.Qy)(e,f[e],"config")}function g(e,t){if(!e)throw new Error("All configuration objects require an agent identifier!");var r=l(e);if(r){for(var n=t.split("."),i=0;i {r.d(t,{D:()=>i});var n=r(50);function i(e,t){try{if(!e||"object"!=typeof e)return(0,n.Z)("Setting a Configurable requires an object as input");if(!t||"object"!=typeof t)return(0,n.Z)("Setting a Configurable requires a model to set its initial properties");const r=Object.create(Object.getPrototypeOf(t),Object.getOwnPropertyDescriptors(t)),o=0===Object.keys(r).length?e:r;for(let a in o)if(void 0!==e[a])try{"object"==typeof e[a]&&"object"==typeof t[a]?r[a]=i(e[a],t[a]):r[a]=e[a]}catch(e){(0,n.Z)("An error occurred while setting a property of a Configurable",e)}return r}catch(e){(0,n.Z)("An error occured while setting a Configurable",e)}}},6818:(e,t,r)=>{r.d(t,{Re:()=>i,gF:()=>o,q4:()=>n});const n="1.236.0",i="PROD",o="CDN"},385:(e,t,r)=>{r.d(t,{FN:()=>a,IF:()=>u,Nk:()=>f,Tt:()=>s,_A:()=>o,il:()=>n,pL:()=>c,v6:()=>i,w1:()=>d});const n="undefined"!=typeof window&&!!window.document,i="undefined"!=typeof WorkerGlobalScope&&("undefined"!=typeof self&&self instanceof WorkerGlobalScope&&self.navigator instanceof WorkerNavigator||"undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope&&globalThis.navigator instanceof WorkerNavigator),o=n?window:"undefined"!=typeof WorkerGlobalScope&&("undefined"!=typeof self&&self instanceof WorkerGlobalScope&&self||"undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope&&globalThis),a=""+o?.location,s=/iPad|iPhone|iPod/.test(navigator.userAgent),c=s&&"undefined"==typeof SharedWorker,u=(()=>{const e=navigator.userAgent.match(/Firefox[/\s](\d+\.\d+)/);return Array.isArray(e)&&e.length>=2?+e[1]:0})(),d=Boolean(n&&window.document.documentMode),f=!!navigator.sendBeacon},1117:(e,t,r)=>{r.d(t,{w:()=>o});var n=r(50);const i={agentIdentifier:"",ee:void 0};class o{constructor(e){try{if("object"!=typeof e)return(0,n.Z)("shared context requires an object as input");this.sharedContext={},Object.assign(this.sharedContext,i),Object.entries(e).forEach((e=>{let[t,r]=e;Object.keys(i).includes(t)&&(this.sharedContext[t]=r)}))}catch(e){(0,n.Z)("An error occured while setting SharedContext",e)}}}},8e3:(e,t,r)=>{r.d(t,{L:()=>d,R:()=>c});var n=r(2177),i=r(1284),o=r(4322),a=r(3325);const s={};function c(e,t){const r={staged:!1,priority:a.p[t]||0};u(e),s[e].get(t)||s[e].set(t,r)}function u(e){e&&(s[e]||(s[e]=new Map))}function d(){let e=arguments.length>0&&void 0!==arguments[0]?arguments[0]:"",t=arguments.length>1&&void 0!==arguments[1]?arguments[1]:"feature";if(u(e),!e||!s[e].get(t))return a(t);s[e].get(t).staged=!0;const r=[...s[e]];function a(t){const r=e?n.ee.get(e):n.ee,a=o.X.handlers;if(r.backlog&&a){var s=r.backlog[t],c=a[t];if(c){for(var u=0;s&&u {let[t,r]=e;return r.staged}))&&(r.sort(((e,t)=>e[1].priority-t[1].priority)),r.forEach((e=>{let[t]=e;a(t)})))}function f(e,t){var r=e[1];(0,i.D)(t[r],(function(t,r){var n=e[0];if(r[0]===n){var i=r[1],o=e[3],a=e[2];i.apply(o,a)}}))}},2177:(e,t,r)=>{r.d(t,{c:()=>f,ee:()=>u});var n=r(8632),i=r(2210),o=r(1284),a=r(5763),s="nr@context";let c=(0,n.fP)();var u;function d(){}function f(e){return(0,i.X)(e,s,l)}function l(){return new d}function h(){u.aborted=!0,u.backlog={}}c.ee?u=c.ee:(u=function e(t,r){var n={},c={},f={},g=!1;try{g=16===r.length&&(0,a.OP)(r).isolatedBacklog}catch(e){}var p={on:b,addEventListener:b,removeEventListener:y,emit:v,get:x,listeners:w,context:m,buffer:A,abort:h,aborted:!1,isBuffering:E,debugId:r,backlog:g?{}:t&&"object"==typeof t.backlog?t.backlog:{}};return p;function m(e){return e&&e instanceof d?e:e?(0,i.X)(e,s,l):l()}function v(e,r,n,i,o){if(!1!==o&&(o=!0),!u.aborted||i){t&&o&&t.emit(e,r,n);for(var a=m(n),s=w(e),d=s.length,f=0;fn,p:()=>i});var n=r(2177).ee.get("handle");function i(e,t,r,i,o){o?(o.buffer([e],i),o.emit(e,t,r)):(n.buffer([e],i),n.emit(e,t,r))}},4322:(e,t,r)=>{r.d(t,{X:()=>o});var n=r(5546);o.on=a;var i=o.handlers={};function o(e,t,r,o){a(o||n.E,i,e,t,r)}function a(e,t,r,i,o){o||(o="feature"),e||(e=n.E);var a=t[o]=t[o]||{};(a[r]=a[r]||[]).push([e,i])}},3239:(e,t,r)=>{r.d(t,{bP:()=>s,iz:()=>c,m$:()=>a});var n=r(385);let i=!1,o=!1;try{const e={get passive(){return i=!0,!1},get signal(){return o=!0,!1}};n._A.addEventListener("test",null,e),n._A.removeEventListener("test",null,e)}catch(e){}function a(e,t){return i||o?{capture:!!e,passive:i,signal:t}:!!e}function s(e,t){let r=arguments.length>2&&void 0!==arguments[2]&&arguments[2],n=arguments.length>3?arguments[3]:void 0;window.addEventListener(e,t,a(r,n))}function c(e,t){let r=arguments.length>2&&void 0!==arguments[2]&&arguments[2],n=arguments.length>3?arguments[3]:void 0;document.addEventListener(e,t,a(r,n))}},4402:(e,t,r)=>{r.d(t,{Ht:()=>u,M:()=>c,Rl:()=>a,ky:()=>s});var n=r(385);const i="xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx";function o(e,t){return e?15&e[t]:16*Math.random()|0}function a(){const e=n._A?.crypto||n._A?.msCrypto;let t,r=0;return e&&e.getRandomValues&&(t=e.getRandomValues(new Uint8Array(31))),i.split("").map((e=>"x"===e?o(t,++r).toString(16):"y"===e?(3&o()|8).toString(16):e)).join("")}function s(e){const t=n._A?.crypto||n._A?.msCrypto;let r,i=0;t&&t.getRandomValues&&(r=t.getRandomValues(new Uint8Array(31)));const a=[];for(var s=0;s {r.d(t,{Bq:()=>n,Hb:()=>o,oD:()=>i});const n="NRBA",i=144e5,o=18e5},7894:(e,t,r)=>{function n(){return Math.round(performance.now())}r.d(t,{z:()=>n})},7243:(e,t,r)=>{r.d(t,{e:()=>o});var n=r(385),i={};function o(e){if(e in i)return i[e];if(0===(e||"").indexOf("data:"))return{protocol:"data"};let t;var r=n._A?.location,o={};if(n.il)t=document.createElement("a"),t.href=e;else try{t=new URL(e,r.href)}catch(e){return o}o.port=t.port;var a=t.href.split("://");!o.port&&a[1]&&(o.port=a[1].split("/")[0].split("@").pop().split(":")[1]),o.port&&"0"!==o.port||(o.port="https"===a[0]?"443":"80"),o.hostname=t.hostname||r.hostname,o.pathname=t.pathname,o.protocol=a[0],"/"!==o.pathname.charAt(0)&&(o.pathname="/"+o.pathname);var s=!t.protocol||":"===t.protocol||t.protocol===r.protocol,c=t.hostname===r.hostname&&t.port===r.port;return o.sameOrigin=s&&(!t.hostname||c),"/"===o.pathname&&(i[e]=o),o}},50:(e,t,r)=>{function n(e,t){"function"==typeof console.warn&&(console.warn("New Relic: ".concat(e)),t&&console.warn(t))}r.d(t,{Z:()=>n})},2587:(e,t,r)=>{r.d(t,{N:()=>c,T:()=>u});var n=r(2177),i=r(5546),o=r(8e3),a=r(3325);const s={stn:[a.D.sessionTrace],err:[a.D.jserrors,a.D.metrics],ins:[a.D.pageAction],spa:[a.D.spa],sr:[a.D.sessionReplay,a.D.sessionTrace]};function c(e,t){const r=n.ee.get(t);e&&"object"==typeof e&&(Object.entries(e).forEach((e=>{let[t,n]=e;void 0===u[t]&&(s[t]?s[t].forEach((e=>{n?(0,i.p)("feat-"+t,[],void 0,e,r):(0,i.p)("block-"+t,[],void 0,e,r),(0,i.p)("rumresp-"+t,[Boolean(n)],void 0,e,r)})):n&&(0,i.p)("feat-"+t,[],void 0,void 0,r),u[t]=Boolean(n))})),Object.keys(s).forEach((e=>{void 0===u[e]&&(s[e]?.forEach((t=>(0,i.p)("rumresp-"+e,[!1],void 0,t,r))),u[e]=!1)})),(0,o.L)(t,a.D.pageViewEvent))}const u={}},2210:(e,t,r)=>{r.d(t,{X:()=>i});var n=Object.prototype.hasOwnProperty;function i(e,t,r){if(n.call(e,t))return e[t];var i=r();if(Object.defineProperty&&Object.keys)try{return Object.defineProperty(e,t,{value:i,writable:!0,enumerable:!1}),i}catch(e){}return e[t]=i,i}},1284:(e,t,r)=>{r.d(t,{D:()=>n});const n=(e,t)=>Object.entries(e||{}).map((e=>{let[r,n]=e;return t(r,n)}))},4351:(e,t,r)=>{r.d(t,{P:()=>o});var n=r(2177);const i=()=>{const e=new WeakSet;return(t,r)=>{if("object"==typeof r&&null!==r){if(e.has(r))return;e.add(r)}return r}};function o(e){try{return JSON.stringify(e,i())}catch(e){try{n.ee.emit("internal-error",[e])}catch(e){}}}},3960:(e,t,r)=>{r.d(t,{K:()=>a,b:()=>o});var n=r(3239);function i(){return"undefined"==typeof document||"complete"===document.readyState}function o(e,t){if(i())return e();(0,n.bP)("load",e,t)}function a(e){if(i())return e();(0,n.iz)("DOMContentLoaded",e)}},8632:(e,t,r)=>{r.d(t,{EZ:()=>u,Qy:()=>c,ce:()=>o,fP:()=>a,gG:()=>d,mF:()=>s});var n=r(7894),i=r(385);const o={beacon:"bam.nr-data.net",errorBeacon:"bam.nr-data.net"};function a(){return i._A.NREUM||(i._A.NREUM={}),void 0===i._A.newrelic&&(i._A.newrelic=i._A.NREUM),i._A.NREUM}function s(){let e=a();return e.o||(e.o={ST:i._A.setTimeout,SI:i._A.setImmediate,CT:i._A.clearTimeout,XHR:i._A.XMLHttpRequest,REQ:i._A.Request,EV:i._A.Event,PR:i._A.Promise,MO:i._A.MutationObserver,FETCH:i._A.fetch}),e}function c(e,t,r){let i=a();const o=i.initializedAgents||{},s=o[e]||{};return Object.keys(s).length||(s.initializedAt={ms:(0,n.z)(),date:new Date}),i.initializedAgents={...o,[e]:{...s,[r]:t}},i}function u(e,t){a()[e]=t}function d(){return function(){let e=a();const t=e.info||{};e.info={beacon:o.beacon,errorBeacon:o.errorBeacon,...t}}(),function(){let e=a();const t=e.init||{};e.init={...t}}(),s(),function(){let e=a();const t=e.loader_config||{};e.loader_config={...t}}(),a()}},7956:(e,t,r)=>{r.d(t,{N:()=>i});var n=r(3239);function i(e){let t=arguments.length>1&&void 0!==arguments[1]&&arguments[1],r=arguments.length>2?arguments[2]:void 0,i=arguments.length>3?arguments[3]:void 0;return void(0,n.iz)("visibilitychange",(function(){if(t)return void("hidden"==document.visibilityState&&e());e(document.visibilityState)}),r,i)}},1214:(e,t,r)=>{r.d(t,{em:()=>v,u5:()=>N,QU:()=>S,_L:()=>I,Gm:()=>L,Lg:()=>M,gy:()=>U,BV:()=>Q,Kf:()=>ee});var n=r(2177);const i="nr@original";var o=Object.prototype.hasOwnProperty,a=!1;function s(e,t){return e||(e=n.ee),r.inPlace=function(e,t,n,i,o){n||(n="");var a,s,c,u="-"===n.charAt(0);for(c=0;c 2?n-2:0),o=2;o {r(A[T],e,w),r(E[T],e,w)})),r(l._A,"fetch",y),t.on(y+"end",(function(e,r){var n=this;if(r){var i=r.headers.get("content-length");null!==i&&(n.rxSize=i),t.emit(y+"done",[null,r],n)}else t.emit(y+"done",[e],n)})),t}const O={},j=["pushState","replaceState"];function S(e){const t=function(e){return(e||n.ee).get("history")}(e);return!l.il||O[t.debugId]++||(O[t.debugId]=1,s(t).inPlace(window.history,j,"-")),t}var P=r(3239);const C={},R=["appendChild","insertBefore","replaceChild"];function I(e){const t=function(e){return(e||n.ee).get("jsonp")}(e);if(!l.il||C[t.debugId])return t;C[t.debugId]=!0;var r=s(t),i=/[?&](?:callback|cb)=([^&#]+)/,o=/(.*)\.([^.]+)/,a=/^(\w+)(\.|$)(.*)$/;function c(e,t){var r=e.match(a),n=r[1],i=r[3];return i?c(i,t[n]):t[n]}return r.inPlace(Node.prototype,R,"dom-"),t.on("dom-start",(function(e){!function(e){if(!e||"string"!=typeof e.nodeName||"script"!==e.nodeName.toLowerCase())return;if("function"!=typeof e.addEventListener)return;var n=(a=e.src,s=a.match(i),s?s[1]:null);var a,s;if(!n)return;var u=function(e){var t=e.match(o);if(t&&t.length>=3)return{key:t[2],parent:c(t[1],window)};return{key:e,parent:window}}(n);if("function"!=typeof u.parent[u.key])return;var d={};function f(){t.emit("jsonp-end",[],d),e.removeEventListener("load",f,(0,P.m$)(!1)),e.removeEventListener("error",l,(0,P.m$)(!1))}function l(){t.emit("jsonp-error",[],d),t.emit("jsonp-end",[],d),e.removeEventListener("load",f,(0,P.m$)(!1)),e.removeEventListener("error",l,(0,P.m$)(!1))}r.inPlace(u.parent,[u.key],"cb-",d),e.addEventListener("load",f,(0,P.m$)(!1)),e.addEventListener("error",l,(0,P.m$)(!1)),t.emit("new-jsonp",[e.src],d)}(e[0])})),t}var k=r(5763);const H={};function L(e){const t=function(e){return(e||n.ee).get("mutation")}(e);if(!l.il||H[t.debugId])return t;H[t.debugId]=!0;var r=s(t),i=k.Yu.MO;return i&&(window.MutationObserver=function(e){return this instanceof i?new i(r(e,"fn-")):i.apply(this,arguments)},MutationObserver.prototype=i.prototype),t}const z={};function M(e){const t=function(e){return(e||n.ee).get("promise")}(e);if(z[t.debugId])return t;z[t.debugId]=!0;var r=n.c,o=s(t),a=k.Yu.PR;return a&&function(){function e(r){var n=t.context(),i=o(r,"executor-",n,null,!1);const s=Reflect.construct(a,[i],e);return t.context(s).getCtx=function(){return n},s}l._A.Promise=e,Object.defineProperty(e,"name",{value:"Promise"}),e.toString=function(){return a.toString()},Object.setPrototypeOf(e,a),["all","race"].forEach((function(r){const n=a[r];e[r]=function(e){let i=!1;[...e||[]].forEach((e=>{this.resolve(e).then(a("all"===r),a(!1))}));const o=n.apply(this,arguments);return o;function a(e){return function(){t.emit("propagate",[null,!i],o,!1,!1),i=i||!e}}}})),["resolve","reject"].forEach((function(r){const n=a[r];e[r]=function(e){const r=n.apply(this,arguments);return e!==r&&t.emit("propagate",[e,!0],r,!1,!1),r}})),e.prototype=a.prototype;const n=a.prototype.then;a.prototype.then=function(){var e=this,i=r(e);i.promise=e;for(var a=arguments.length,s=new Array(a),c=0;c e())),t};function m(e,t){i.inPlace(t,["onreadystatechange"],"fn-",E)}function b(){var e=this,t=r.context(e);e.readyState>3&&!t.resolved&&(t.resolved=!0,r.emit("xhr-resolved",[],e)),i.inPlace(e,f,"fn-",E)}if(function(e,t){for(var r in e)t[r]=e[r]}(o,p),p.prototype=o.prototype,i.inPlace(p.prototype,J,"-xhr-",E),r.on("send-xhr-start",(function(e,t){m(e,t),function(e){h.push(e),a&&(y?y.then(A):u?u(A):(w=-w,x.data=w))}(t)})),r.on("open-xhr-start",m),a){var y=c&&c.resolve();if(!u&&!c){var w=1,x=document.createTextNode(w);new a(A).observe(x,{characterData:!0})}}else t.on("fn-end",(function(e){e[0]&&e[0].type===d||A()}));function A(){for(var e=0;e {r.d(t,{t:()=>n});const n=r(3325).D.ajax},6660:(e,t,r)=>{r.d(t,{A:()=>i,t:()=>n});const n=r(3325).D.jserrors,i="nr@seenError"},3081:(e,t,r)=>{r.d(t,{gF:()=>o,mY:()=>i,t9:()=>n,vz:()=>s,xS:()=>a});const n=r(3325).D.metrics,i="sm",o="cm",a="storeSupportabilityMetrics",s="storeEventMetrics"},4649:(e,t,r)=>{r.d(t,{t:()=>n});const n=r(3325).D.pageAction},7633:(e,t,r)=>{r.d(t,{Dz:()=>i,OJ:()=>a,qw:()=>o,t9:()=>n});const n=r(3325).D.pageViewEvent,i="firstbyte",o="domcontent",a="windowload"},9251:(e,t,r)=>{r.d(t,{t:()=>n});const n=r(3325).D.pageViewTiming},3614:(e,t,r)=>{r.d(t,{BST_RESOURCE:()=>i,END:()=>s,FEATURE_NAME:()=>n,FN_END:()=>u,FN_START:()=>c,PUSH_STATE:()=>d,RESOURCE:()=>o,START:()=>a});const n=r(3325).D.sessionTrace,i="bstResource",o="resource",a="-start",s="-end",c="fn"+a,u="fn"+s,d="pushState"},7836:(e,t,r)=>{r.d(t,{BODY:()=>A,CB_END:()=>E,CB_START:()=>u,END:()=>x,FEATURE_NAME:()=>i,FETCH:()=>_,FETCH_BODY:()=>v,FETCH_DONE:()=>m,FETCH_START:()=>p,FN_END:()=>c,FN_START:()=>s,INTERACTION:()=>l,INTERACTION_API:()=>d,INTERACTION_EVENTS:()=>o,JSONP_END:()=>b,JSONP_NODE:()=>g,JS_TIME:()=>T,MAX_TIMER_BUDGET:()=>a,REMAINING:()=>f,SPA_NODE:()=>h,START:()=>w,originalSetTimeout:()=>y});var n=r(5763);const i=r(3325).D.spa,o=["click","submit","keypress","keydown","keyup","change"],a=999,s="fn-start",c="fn-end",u="cb-start",d="api-ixn-",f="remaining",l="interaction",h="spaNode",g="jsonpNode",p="fetch-start",m="fetch-done",v="fetch-body-",b="jsonp-end",y=n.Yu.ST,w="-start",x="-end",A="-body",E="cb"+x,T="jsTime",_="fetch"},5938:(e,t,r)=>{r.d(t,{W:()=>o});var n=r(5763),i=r(2177);class o{constructor(e,t,r){this.agentIdentifier=e,this.aggregator=t,this.ee=i.ee.get(e,(0,n.OP)(this.agentIdentifier).isolatedBacklog),this.featureName=r,this.blocked=!1}}},9144:(e,t,r)=>{r.d(t,{j:()=>m});var n=r(3325),i=r(5763),o=r(5546),a=r(2177),s=r(7894),c=r(8e3),u=r(3960),d=r(385),f=r(50),l=r(3081),h=r(8632);function g(){const e=(0,h.gG)();["setErrorHandler","finished","addToTrace","inlineHit","addRelease","addPageAction","setCurrentRouteName","setPageViewName","setCustomAttribute","interaction","noticeError","setUserId"].forEach((t=>{e[t]=function(){for(var r=arguments.length,n=new Array(r),i=0;i 1?r-1:0),i=1;i {e.exposed&&e.api[t]&&o.push(e.api[t](...n))})),o.length>1?o:o[0]}(t,...n)}}))}var p=r(2587);function m(e){let t=arguments.length>1&&void 0!==arguments[1]?arguments[1]:{},m=arguments.length>2?arguments[2]:void 0,v=arguments.length>3?arguments[3]:void 0,{init:b,info:y,loader_config:w,runtime:x={loaderType:m},exposed:A=!0}=t;const E=(0,h.gG)();y||(b=E.init,y=E.info,w=E.loader_config),(0,i.Dg)(e,b||{}),(0,i.GE)(e,w||{}),(0,i.sU)(e,x),y.jsAttributes??={},d.v6&&(y.jsAttributes.isWorker=!0),(0,i.CX)(e,y),g();const T=function(e,t){t||(0,c.R)(e,"api");const h={};var g=a.ee.get(e),p=g.get("tracer"),m="api-",v=m+"ixn-";function b(t,r,n,o){const a=(0,i.C5)(e);return null===r?delete a.jsAttributes[t]:(0,i.CX)(e,{...a,jsAttributes:{...a.jsAttributes,[t]:r}}),x(m,n,!0,o||null===r?"session":void 0)(t,r)}function y(){}["setErrorHandler","finished","addToTrace","inlineHit","addRelease"].forEach((e=>h[e]=x(m,e,!0,"api"))),h.addPageAction=x(m,"addPageAction",!0,n.D.pageAction),h.setCurrentRouteName=x(m,"routeName",!0,n.D.spa),h.setPageViewName=function(t,r){if("string"==typeof t)return"/"!==t.charAt(0)&&(t="/"+t),(0,i.OP)(e).customTransaction=(r||"http://custom.transaction")+t,x(m,"setPageViewName",!0)()},h.setCustomAttribute=function(e,t){let r=arguments.length>2&&void 0!==arguments[2]&&arguments[2];if("string"==typeof e){if(["string","number"].includes(typeof t)||null===t)return b(e,t,"setCustomAttribute",r);(0,f.Z)("Failed to execute setCustomAttribute.\nNon-null value must be a string or number type, but a type of was provided."))}else(0,f.Z)("Failed to execute setCustomAttribute.\nName must be a string type, but a type of was provided."))},h.setUserId=function(e){if("string"==typeof e||null===e)return b("enduser.id",e,"setUserId",!0);(0,f.Z)("Failed to execute setUserId.\nNon-null value must be a string type, but a type of was provided."))},h.interaction=function(){return(new y).get()};var w=y.prototype={createTracer:function(e,t){var r={},i=this,a="function"==typeof t;return(0,o.p)(v+"tracer",[(0,s.z)(),e,r],i,n.D.spa,g),function(){if(p.emit((a?"":"no-")+"fn-start",[(0,s.z)(),i,a],r),a)try{return t.apply(this,arguments)}catch(e){throw p.emit("fn-err",[arguments,this,"string"==typeof e?new Error(e):e],r),e}finally{p.emit("fn-end",[(0,s.z)()],r)}}}};function x(e,t,r,i){return function(){return(0,o.p)(l.xS,["API/"+t+"/called"],void 0,n.D.metrics,g),i&&(0,o.p)(e+t,[(0,s.z)(),...arguments],r?null:this,i,g),r?void 0:this}}function A(){r.e(439).then(r.bind(r,7438)).then((t=>{let{setAPI:r}=t;r(e),(0,c.L)(e,"api")})).catch((()=>(0,f.Z)("Downloading runtime APIs failed...")))}return["actionText","setName","setAttribute","save","ignore","onEnd","getContext","end","get"].forEach((e=>{w[e]=x(v,e,void 0,n.D.spa)})),h.noticeError=function(e,t){"string"==typeof e&&(e=new Error(e)),(0,o.p)(l.xS,["API/noticeError/called"],void 0,n.D.metrics,g),(0,o.p)("err",[e,(0,s.z)(),!1,t],void 0,n.D.jserrors,g)},d.il?(0,u.b)((()=>A()),!0):A(),h}(e,v);return(0,h.Qy)(e,T,"api"),(0,h.Qy)(e,A,"exposed"),(0,h.EZ)("activatedFeatures",p.T),T}},3325:(e,t,r)=>{r.d(t,{D:()=>n,p:()=>i});const n={ajax:"ajax",jserrors:"jserrors",metrics:"metrics",pageAction:"page_action",pageViewEvent:"page_view_event",pageViewTiming:"page_view_timing",sessionReplay:"session_replay",sessionTrace:"session_trace",spa:"spa"},i={[n.pageViewEvent]:1,[n.pageViewTiming]:2,[n.metrics]:3,[n.jserrors]:4,[n.ajax]:5,[n.sessionTrace]:6,[n.pageAction]:7,[n.spa]:8,[n.sessionReplay]:9}}},n={};function i(e){var t=n[e];if(void 0!==t)return t.exports;var o=n[e]={exports:{}};return r[e](o,o.exports,i),o.exports}i.m=r,i.d=(e,t)=>{for(var r in t)i.o(t,r)&&!i.o(e,r)&&Object.defineProperty(e,r,{enumerable:!0,get:t[r]})},i.f={},i.e=e=>Promise.all(Object.keys(i.f).reduce(((t,r)=>(i.f[r](e,t),t)),[])),i.u=e=>(({78:"page_action-aggregate",147:"metrics-aggregate",242:"session-manager",317:"jserrors-aggregate",348:"page_view_timing-aggregate",412:"lazy-feature-loader",439:"async-api",538:"recorder",590:"session_replay-aggregate",675:"compressor",733:"session_trace-aggregate",786:"page_view_event-aggregate",873:"spa-aggregate",898:"ajax-aggregate"}[e]||e)+"."+{78:"ac76d497",147:"3dc53903",148:"1a20d5fe",242:"2a64278a",317:"49e41428",348:"bd6de33a",412:"2f55ce66",439:"30bd804e",538:"1b18459f",590:"cf0efb30",675:"ae9f91a8",733:"83105561",786:"06482edd",860:"03a8b7a5",873:"e6b09d52",898:"998ef92b"}[e]+"-1.236.0.min.js"),i.o=(e,t)=>Object.prototype.hasOwnProperty.call(e,t),e={},t="NRBA:",i.l=(r,n,o,a)=>{if(e[r])e[r].push(n);else{var s,c;if(void 0!==o)for(var u=document.getElementsByTagName("script"),d=0;d {s.onerror=s.onload=null,clearTimeout(h);var i=e[r];if(delete e[r],s.parentNode&&s.parentNode.removeChild(s),i&&i.forEach((e=>e(n))),t)return t(n)},h=setTimeout(l.bind(null,void 0,{type:"timeout",target:s}),12e4);s.onerror=l.bind(null,s.onerror),s.onload=l.bind(null,s.onload),c&&document.head.appendChild(s)}},i.r=e=>{"undefined"!=typeof Symbol&&Symbol.toStringTag&&Object.defineProperty(e,Symbol.toStringTag,{value:"Module"}),Object.defineProperty(e,"__esModule",{value:!0})},i.j=364,i.p="https://js-agent.newrelic.com/",(()=>{var e={364:0,953:0};i.f.j=(t,r)=>{var n=i.o(e,t)?e[t]:void 0;if(0!==n)if(n)r.push(n[2]);else{var o=new Promise(((r,i)=>n=e[t]=[r,i]));r.push(n[2]=o);var a=i.p+i.u(t),s=new Error;i.l(a,(r=>{if(i.o(e,t)&&(0!==(n=e[t])&&(e[t]=void 0),n)){var o=r&&("load"===r.type?"missing":r.type),a=r&&r.target&&r.target.src;s.message="Loading chunk "+t+" failed.\n("+o+": "+a+")",s.name="ChunkLoadError",s.type=o,s.request=a,n[1](s)}}),"chunk-"+t,t)}};var t=(t,r)=>{var n,o,[a,s,c]=r,u=0;if(a.some((t=>0!==e[t]))){for(n in s)i.o(s,n)&&(i.m[n]=s[n]);if(c)c(i)}for(t&&t(r);u {i.r(o);var e=i(3325),t=i(5763);const r=Object.values(e.D);function n(e){const n={};return r.forEach((r=>{n[r]=function(e,r){return!1!==(0,t.Mt)(r,"".concat(e,".enabled"))}(r,e)})),n}var a=i(9144);var s=i(5546),c=i(385),u=i(8e3),d=i(5938),f=i(3960),l=i(50);class h extends d.W{constructor(e,t,r){let n=!(arguments.length>3&&void 0!==arguments[3])||arguments[3];super(e,t,r),this.auto=n,this.abortHandler,this.featAggregate,this.onAggregateImported,n&&(0,u.R)(e,r)}importAggregator(){let e=arguments.length>0&&void 0!==arguments[0]?arguments[0]:{};if(this.featAggregate||!this.auto)return;const r=c.il&&!0===(0,t.Mt)(this.agentIdentifier,"privacy.cookies_enabled");let n;this.onAggregateImported=new Promise((e=>{n=e}));const o=async()=>{let t;try{if(r){const{setupAgentSession:e}=await Promise.all([i.e(860),i.e(242)]).then(i.bind(i,3228));t=e(this.agentIdentifier)}}catch(e){(0,l.Z)("A problem occurred when starting up session manager. This page will not start or extend any session.",e)}try{if(!this.shouldImportAgg(this.featureName,t))return void(0,u.L)(this.agentIdentifier,this.featureName);const{lazyFeatureLoader:r}=await i.e(412).then(i.bind(i,8582)),{Aggregate:o}=await r(this.featureName,"aggregate");this.featAggregate=new o(this.agentIdentifier,this.aggregator,e),n(!0)}catch(e){(0,l.Z)("Downloading and initializing ".concat(this.featureName," failed..."),e),this.abortHandler?.(),n(!1)}};c.il?(0,f.b)((()=>o()),!0):o()}shouldImportAgg(r,n){return r!==e.D.sessionReplay||!1!==(0,t.Mt)(this.agentIdentifier,"session_trace.enabled")&&(!!n?.isNew||!!n?.state.sessionReplay)}}var g=i(7633),p=i(7894);class m extends h{static featureName=g.t9;constructor(r,n){let i=!(arguments.length>2&&void 0!==arguments[2])||arguments[2];if(super(r,n,g.t9,i),("undefined"==typeof PerformanceNavigationTiming||c.Tt)&&"undefined"!=typeof PerformanceTiming){const n=(0,t.OP)(r);n[g.Dz]=Math.max(Date.now()-n.offset,0),(0,f.K)((()=>n[g.qw]=Math.max((0,p.z)()-n[g.Dz],0))),(0,f.b)((()=>{const t=(0,p.z)();n[g.OJ]=Math.max(t-n[g.Dz],0),(0,s.p)("timing",["load",t],void 0,e.D.pageViewTiming,this.ee)}))}this.importAggregator()}}var v=i(1117),b=i(1284);class y extends v.w{constructor(e){super(e),this.aggregatedData={}}store(e,t,r,n,i){var o=this.getBucket(e,t,r,i);return o.metrics=function(e,t){t||(t={count:0});return t.count+=1,(0,b.D)(e,(function(e,r){t[e]=w(r,t[e])})),t}(n,o.metrics),o}merge(e,t,r,n,i){var o=this.getBucket(e,t,n,i);if(o.metrics){var a=o.metrics;a.count+=r.count,(0,b.D)(r,(function(e,t){if("count"!==e){var n=a[e],i=r[e];i&&!i.c?a[e]=w(i.t,n):a[e]=function(e,t){if(!t)return e;t.c||(t=x(t.t));return t.min=Math.min(e.min,t.min),t.max=Math.max(e.max,t.max),t.t+=e.t,t.sos+=e.sos,t.c+=e.c,t}(i,a[e])}}))}else o.metrics=r}storeMetric(e,t,r,n){var i=this.getBucket(e,t,r);return i.stats=w(n,i.stats),i}getBucket(e,t,r,n){this.aggregatedData[e]||(this.aggregatedData[e]={});var i=this.aggregatedData[e][t];return i||(i=this.aggregatedData[e][t]={params:r||{}},n&&(i.custom=n)),i}get(e,t){return t?this.aggregatedData[e]&&this.aggregatedData[e][t]:this.aggregatedData[e]}take(e){for(var t={},r="",n=!1,i=0;i t.max&&(t.max=e),e 2&&void 0!==arguments[2])||arguments[2];super(e,r,j.t,n),c.il&&((0,t.OP)(e).initHidden=Boolean("hidden"===document.visibilityState),(0,N.N)((()=>(0,s.p)("docHidden",[(0,p.z)()],void 0,j.t,this.ee)),!0),(0,O.bP)("pagehide",(()=>(0,s.p)("winPagehide",[(0,p.z)()],void 0,j.t,this.ee))),this.importAggregator())}}var P=i(3081);class C extends h{static featureName=P.t9;constructor(e,t){let r=!(arguments.length>2&&void 0!==arguments[2])||arguments[2];super(e,t,P.t9,r),this.importAggregator()}}var R,I=i(2210),k=i(1214),H=i(2177),L={};try{R=localStorage.getItem("__nr_flags").split(","),console&&"function"==typeof console.log&&(L.console=!0,-1!==R.indexOf("dev")&&(L.dev=!0),-1!==R.indexOf("nr_dev")&&(L.nrDev=!0))}catch(e){}function z(e){try{L.console&&z(e)}catch(e){}}L.nrDev&&H.ee.on("internal-error",(function(e){z(e.stack)})),L.dev&&H.ee.on("fn-err",(function(e,t,r){z(r.stack)})),L.dev&&(z("NR AGENT IN DEVELOPMENT MODE"),z("flags: "+(0,b.D)(L,(function(e,t){return e})).join(", ")));var M=i(6660);class B extends h{static featureName=M.t;constructor(r,n){let i=!(arguments.length>2&&void 0!==arguments[2])||arguments[2];super(r,n,M.t,i),this.skipNext=0;try{this.removeOnAbort=new AbortController}catch(e){}const o=this;o.ee.on("fn-start",(function(e,t,r){o.abortHandler&&(o.skipNext+=1)})),o.ee.on("fn-err",(function(t,r,n){o.abortHandler&&!n[M.A]&&((0,I.X)(n,M.A,(function(){return!0})),this.thrown=!0,(0,s.p)("err",[n,(0,p.z)()],void 0,e.D.jserrors,o.ee))})),o.ee.on("fn-end",(function(){o.abortHandler&&!this.thrown&&o.skipNext>0&&(o.skipNext-=1)})),o.ee.on("internal-error",(function(t){(0,s.p)("ierr",[t,(0,p.z)(),!0],void 0,e.D.jserrors,o.ee)})),this.origOnerror=c._A.onerror,c._A.onerror=this.onerrorHandler.bind(this),c._A.addEventListener("unhandledrejection",(t=>{const r=function(e){let t="Unhandled Promise Rejection: ";if(e instanceof Error)try{return e.message=t+e.message,e}catch(t){return e}if(void 0===e)return new Error(t);try{return new Error(t+(0,D.P)(e))}catch(e){return new Error(t)}}(t.reason);(0,s.p)("err",[r,(0,p.z)(),!1,{unhandledPromiseRejection:1}],void 0,e.D.jserrors,this.ee)}),(0,O.m$)(!1,this.removeOnAbort?.signal)),(0,k.gy)(this.ee),(0,k.BV)(this.ee),(0,k.em)(this.ee),(0,t.OP)(r).xhrWrappable&&(0,k.Kf)(this.ee),this.abortHandler=this.#e,this.importAggregator()}#e(){this.removeOnAbort?.abort(),this.abortHandler=void 0}onerrorHandler(t,r,n,i,o){"function"==typeof this.origOnerror&&this.origOnerror(...arguments);try{this.skipNext?this.skipNext-=1:(0,s.p)("err",[o||new F(t,r,n),(0,p.z)()],void 0,e.D.jserrors,this.ee)}catch(t){try{(0,s.p)("ierr",[t,(0,p.z)(),!0],void 0,e.D.jserrors,this.ee)}catch(e){}}return!1}}function F(e,t,r){this.message=e||"Uncaught error with no additional information",this.sourceURL=t,this.line=r}let U=1;const q="nr@id";function G(e){const t=typeof e;return!e||"object"!==t&&"function"!==t?-1:e===c._A?0:(0,I.X)(e,q,(function(){return U++}))}function V(e){if("string"==typeof e&&e.length)return e.length;if("object"==typeof e){if("undefined"!=typeof ArrayBuffer&&e instanceof ArrayBuffer&&e.byteLength)return e.byteLength;if("undefined"!=typeof Blob&&e instanceof Blob&&e.size)return e.size;if(!("undefined"!=typeof FormData&&e instanceof FormData))try{return(0,D.P)(e).length}catch(e){return}}}var X=i(7243);class W{constructor(e){this.agentIdentifier=e,this.generateTracePayload=this.generateTracePayload.bind(this),this.shouldGenerateTrace=this.shouldGenerateTrace.bind(this)}generateTracePayload(e){if(!this.shouldGenerateTrace(e))return null;var r=(0,t.DL)(this.agentIdentifier);if(!r)return null;var n=(r.accountID||"").toString()||null,i=(r.agentID||"").toString()||null,o=(r.trustKey||"").toString()||null;if(!n||!i)return null;var a=(0,_.M)(),s=(0,_.Ht)(),c=Date.now(),u={spanId:a,traceId:s,timestamp:c};return(e.sameOrigin||this.isAllowedOrigin(e)&&this.useTraceContextHeadersForCors())&&(u.traceContextParentHeader=this.generateTraceContextParentHeader(a,s),u.traceContextStateHeader=this.generateTraceContextStateHeader(a,c,n,i,o)),(e.sameOrigin&&!this.excludeNewrelicHeader()||!e.sameOrigin&&this.isAllowedOrigin(e)&&this.useNewrelicHeaderForCors())&&(u.newrelicHeader=this.generateTraceHeader(a,s,c,n,i,o)),u}generateTraceContextParentHeader(e,t){return"00-"+t+"-"+e+"-01"}generateTraceContextStateHeader(e,t,r,n,i){return i+"@nr=0-1-"+r+"-"+n+"-"+e+"----"+t}generateTraceHeader(e,t,r,n,i,o){if(!("function"==typeof c._A?.btoa))return null;var a={v:[0,1],d:{ty:"Browser",ac:n,ap:i,id:e,tr:t,ti:r}};return o&&n!==o&&(a.d.tk=o),btoa((0,D.P)(a))}shouldGenerateTrace(e){return this.isDtEnabled()&&this.isAllowedOrigin(e)}isAllowedOrigin(e){var r=!1,n={};if((0,t.Mt)(this.agentIdentifier,"distributed_tracing")&&(n=(0,t.P_)(this.agentIdentifier).distributed_tracing),e.sameOrigin)r=!0;else if(n.allowed_origins instanceof Array)for(var i=0;i 2&&void 0!==arguments[2])||arguments[2];super(r,n,Z.t,i),(0,t.OP)(r).xhrWrappable&&(this.dt=new W(r),this.handler=(e,t,r,n)=>(0,s.p)(e,t,r,n,this.ee),(0,k.u5)(this.ee),(0,k.Kf)(this.ee),function(r,n,i,o){function a(e){var t=this;t.totalCbs=0,t.called=0,t.cbTime=0,t.end=E,t.ended=!1,t.xhrGuids={},t.lastSize=null,t.loadCaptureCalled=!1,t.params=this.params||{},t.metrics=this.metrics||{},e.addEventListener("load",(function(r){_(t,e)}),(0,O.m$)(!1)),c.IF||e.addEventListener("progress",(function(e){t.lastSize=e.loaded}),(0,O.m$)(!1))}function s(e){this.params={method:e[0]},T(this,e[1]),this.metrics={}}function u(e,n){var i=(0,t.DL)(r);i.xpid&&this.sameOrigin&&n.setRequestHeader("X-NewRelic-ID",i.xpid);var a=o.generateTracePayload(this.parsedOrigin);if(a){var s=!1;a.newrelicHeader&&(n.setRequestHeader("newrelic",a.newrelicHeader),s=!0),a.traceContextParentHeader&&(n.setRequestHeader("traceparent",a.traceContextParentHeader),a.traceContextStateHeader&&n.setRequestHeader("tracestate",a.traceContextStateHeader),s=!0),s&&(this.dt=a)}}function d(e,t){var r=this.metrics,i=e[0],o=this;if(r&&i){var a=V(i);a&&(r.txSize=a)}this.startTime=(0,p.z)(),this.listener=function(e){try{"abort"!==e.type||o.loadCaptureCalled||(o.params.aborted=!0),("load"!==e.type||o.called===o.totalCbs&&(o.onloadCalled||"function"!=typeof t.onload)&&"function"==typeof o.end)&&o.end(t)}catch(e){try{n.emit("internal-error",[e])}catch(e){}}};for(var s=0;s 1?e[1]=i:e.push(i)}else e[0]&&e[0].headers&&s(e[0].headers,n)&&(this.dt=n);function s(e,t){var r=!1;return t.newrelicHeader&&(e.set("newrelic",t.newrelicHeader),r=!0),t.traceContextParentHeader&&(e.set("traceparent",t.traceContextParentHeader),t.traceContextStateHeader&&e.set("tracestate",t.traceContextStateHeader),r=!0),r}}function x(e,t){this.params={},this.metrics={},this.startTime=(0,p.z)(),this.dt=t,e.length>=1&&(this.target=e[0]),e.length>=2&&(this.opts=e[1]);var r,n=this.opts||{},i=this.target;"string"==typeof i?r=i:"object"==typeof i&&i instanceof Y?r=i.url:c._A?.URL&&"object"==typeof i&&i instanceof URL&&(r=i.href),T(this,r);var o=(""+(i&&i instanceof Y&&i.method||n.method||"GET")).toUpperCase();this.params.method=o,this.txSize=V(n.body)||0}function A(t,r){var n;this.endTime=(0,p.z)(),this.params||(this.params={}),this.params.status=r?r.status:0,"string"==typeof this.rxSize&&this.rxSize.length>0&&(n=+this.rxSize);var o={txSize:this.txSize,rxSize:n,duration:(0,p.z)()-this.startTime};i("xhr",[this.params,o,this.startTime,this.endTime,"fetch"],this,e.D.ajax)}function E(t){var r=this.params,n=this.metrics;if(!this.ended){this.ended=!0;for(var o=0;o 2&&void 0!==arguments[2])||arguments[2];super(e,t,we.t,r),this.importAggregator()}}new class{constructor(e){let t=arguments.length>1&&void 0!==arguments[1]?arguments[1]:(0,_.ky)(16);c._A?(this.agentIdentifier=t,this.sharedAggregator=new y({agentIdentifier:this.agentIdentifier}),this.features={},this.desiredFeatures=new Set(e.features||[]),this.desiredFeatures.add(m),Object.assign(this,(0,a.j)(this.agentIdentifier,e,e.loaderType||"agent")),this.start()):(0,l.Z)("Failed to initial the agent. Could not determine the runtime environment.")}get config(){return{info:(0,t.C5)(this.agentIdentifier),init:(0,t.P_)(this.agentIdentifier),loader_config:(0,t.DL)(this.agentIdentifier),runtime:(0,t.OP)(this.agentIdentifier)}}start(){const t="features";try{const r=n(this.agentIdentifier),i=[...this.desiredFeatures];i.sort(((t,r)=>e.p[t.featureName]-e.p[r.featureName])),i.forEach((t=>{if(r[t.featureName]||t.featureName===e.D.pageViewEvent){const n=function(t){switch(t){case e.D.ajax:return[e.D.jserrors];case e.D.sessionTrace:return[e.D.ajax,e.D.pageViewEvent];case e.D.sessionReplay:return[e.D.sessionTrace];case e.D.pageViewTiming:return[e.D.pageViewEvent];default:return[]}}(t.featureName);n.every((e=>r[e]))||(0,l.Z)("".concat(t.featureName," is enabled but one or more dependent features has been disabled (").concat((0,D.P)(n),"). This may cause unintended consequences or missing data...")),this.features[t.featureName]=new t(this.agentIdentifier,this.sharedAggregator)}})),(0,T.Qy)(this.agentIdentifier,this.features,t)}catch(e){(0,l.Z)("Failed to initialize all enabled instrument classes (agent aborted) -",e);for(const e in this.features)this.features[e].abortHandler?.();const r=(0,T.fP)();return delete r.initializedAgents[this.agentIdentifier]?.api,delete r.initializedAgents[this.agentIdentifier]?.[t],delete this.sharedAggregator,r.ee?.abort(),delete r.ee?.get(this.agentIdentifier),!1}}}({features:[J,m,S,class extends h{static featureName=oe;constructor(t,r){if(super(t,r,oe,!(arguments.length>2&&void 0!==arguments[2])||arguments[2]),!c.il)return;const n=this.ee;let i;(0,k.QU)(n),this.eventsEE=(0,k.em)(n),this.eventsEE.on(se,(function(e,t){this.bstStart=(0,p.z)()})),this.eventsEE.on(ae,(function(t,r){(0,s.p)("bst",[t[0],r,this.bstStart,(0,p.z)()],void 0,e.D.sessionTrace,n)})),n.on(ce+ne,(function(e){this.time=(0,p.z)(),this.startPath=location.pathname+location.hash})),n.on(ce+ie,(function(t){(0,s.p)("bstHist",[location.pathname+location.hash,this.startPath,this.time],void 0,e.D.sessionTrace,n)}));try{i=new PerformanceObserver((t=>{const r=t.getEntries();(0,s.p)(te,[r],void 0,e.D.sessionTrace,n)})),i.observe({type:re,buffered:!0})}catch(e){}this.importAggregator({resourceObserver:i})}},C,xe,B,class extends h{static featureName=de;constructor(e,r){if(super(e,r,de,!(arguments.length>2&&void 0!==arguments[2])||arguments[2]),!c.il)return;if(!(0,t.OP)(e).xhrWrappable)return;try{this.removeOnAbort=new AbortController}catch(e){}let n,i=0;const o=this.ee.get("tracer"),a=(0,k._L)(this.ee),s=(0,k.Lg)(this.ee),u=(0,k.BV)(this.ee),d=(0,k.Kf)(this.ee),f=this.ee.get("events"),l=(0,k.u5)(this.ee),h=(0,k.QU)(this.ee),g=(0,k.Gm)(this.ee);function m(e,t){h.emit("newURL",[""+window.location,t])}function v(){i++,n=window.location.hash,this[ve]=(0,p.z)()}function b(){i--,window.location.hash!==n&&m(0,!0);var e=(0,p.z)();this[pe]=~~this[pe]+e-this[ve],this[ye]=e}function y(e,t){e.on(t,(function(){this[t]=(0,p.z)()}))}this.ee.on(ve,v),s.on(be,v),a.on(be,v),this.ee.on(ye,b),s.on(ge,b),a.on(ge,b),this.ee.buffer([ve,ye,"xhr-resolved"],this.featureName),f.buffer([ve],this.featureName),u.buffer(["setTimeout"+le,"clearTimeout"+fe,ve],this.featureName),d.buffer([ve,"new-xhr","send-xhr"+fe],this.featureName),l.buffer([me+fe,me+"-done",me+he+fe,me+he+le],this.featureName),h.buffer(["newURL"],this.featureName),g.buffer([ve],this.featureName),s.buffer(["propagate",be,ge,"executor-err","resolve"+fe],this.featureName),o.buffer([ve,"no-"+ve],this.featureName),a.buffer(["new-jsonp","cb-start","jsonp-error","jsonp-end"],this.featureName),y(l,me+fe),y(l,me+"-done"),y(a,"new-jsonp"),y(a,"jsonp-end"),y(a,"cb-start"),h.on("pushState-end",m),h.on("replaceState-end",m),window.addEventListener("hashchange",m,(0,O.m$)(!0,this.removeOnAbort?.signal)),window.addEventListener("load",m,(0,O.m$)(!0,this.removeOnAbort?.signal)),window.addEventListener("popstate",(function(){m(0,i>1)}),(0,O.m$)(!0,this.removeOnAbort?.signal)),this.abortHandler=this.#e,this.importAggregator()}#e(){this.removeOnAbort?.abort(),this.abortHandler=void 0}}],loaderType:"spa"})})(),window.NRBA=o})(); window.jQuery || document.write(' ') CKEDITOR_BASEPATH='https://f1000research.com/js/vendor/ckeditor/' window.reactTheme = 'research'; window.MathJax = { CommonHTML: { linebreaks: { automatic: true } }, 'HTML-CSS': { linebreaks: { automatic: true } }, SVG: { linebreaks: { automatic: true } }, AuthorInit: function() { MathJax.Hub.Register.MessageHook('End Process', function () { let timeout = false; // holder for timeout id const delay = 250; // delay after event is "complete" to run callback const reflowMath = function() { const dispFormulas = document.querySelectorAll('.disp-formula.panel'); if (!dispFormulas) { return; } for (const dispFormula of dispFormulas) { const child = dispFormula.querySelector('.MathJax_Preview').nextSibling.firstChild; const isMultiline = MathJax.Hub.getAllJax(dispFormula)[0].root.isMultiline; if (dispFormula.offsetWidth < child.offsetWidth || isMultiline) { MathJax.Hub.Queue(['Rerender', MathJax.Hub, dispFormula]); } } }; window.addEventListener('resize', function() { clearTimeout(timeout); // clear the timeout timeout = setTimeout(reflowMath, delay); // start timing for event "completion" }); }); }, }; if (window.location.hash == '#_=_'){ window.location = window.location.href.split('#')[0] } !function(f,b,e,v,n,t,s){if(f.fbq)return;n=f.fbq=function() {n.callMethod? n.callMethod.apply(n,arguments):n.queue.push(arguments)} ;if(!f._fbq)f._fbq=n; n.push=n;n.loaded=!0;n.version='2.0';n.queue=[];t=b.createElement(e);t.async=!0; t.src=v;s=b.getElementsByTagName(e)[0];s.parentNode.insertBefore(t,s)}(window, document,'script','https://connect.facebook.net/en_US/fbevents.js'); fbq('init', '1641728616063202'); fbq('track', "PixelInitialized", {}); (function(h,o,t,j,a,r){ h.hj=h.hj||function(){(h.hj.q=h.hj.q||[]).push(arguments)}; h._hjSettings={hjid:2318163,hjsv:6}; a=o.getElementsByTagName('head')[0]; r=o.createElement('script');r.async=1; r.src=t+h._hjSettings.hjid+j+h._hjSettings.hjsv; a.appendChild(r); })(window,document,'https://static.hotjar.com/c/hotjar-','.js?sv='); search file_upload Submit your research search menu close search Browse Gateways & Collections How to Publish Submit your Research My Submissions Article Guidelines Article Guidelines (New Versions) Open Data, Software and Code Guidelines Open Data and Accessible Source Materials Guidelines (HSS) Open Data, Software and Code Guidelines (PSE) Prepublication Checks Production Process Posters and Slides Guidelines Document Guidelines Article Processing Charges Peer Review Finding Article Reviewers About How it Works For Reviewers Our Advisors Policies Glossary FAQs For Developers Newsroom Contact My Research Submissions Content and Tracking Alerts My Details Sign In file_upload Submit your research { "@context": "https://schema.org", "@type": "ScholarlyArticle", "mainEntityOfPage": { "@type": "WebPage", "@id": "https://f1000research.com/articles/12-199" }, "headline": "Social distancing between personal belongings during the COVID-19 pandemic", "datePublished": "2023-02-20T17:24:48", "dateModified": "2025-02-05T16:32:13", "author": [ { "@type": "Person", "name": "Wen Guo" }, { "@type": "Person", "name": "Ayumi Ikeda" }, { "@type": "Person", "name": "Kaito Takashima" }, { "@type": "Person", "name": "Yoshitaka Masuda" }, { "@type": "Person", "name": "Kohei Ueda" }, { "@type": "Person", "name": "Atsunori Ariga" }, { "@type": "Person", "name": "Kyoshiro Sasaki" }, { "@type": "Person", "name": "Yuki Yamada" } ], "publisher": { "@type": "Organization", "name": "F1000Research", "logo": { "@type": "ImageObject", "url": "https://f1000research.com/img/AMP/F1000Research_image.png", "height": 480, "width": 60 } }, "image": { "@type": "ImageObject", "url": "https://f1000research.com/img/AMP/F1000Research_image.png", "height": 1200, "width": 150 }, "description": " Background The COVID-19 pandemic has led to instructions and suggestions from governments and experts to maintain social (physical) distance between people to prevent aerosol transmission of the virus, which is now becoming the norm. Thus, we examined whether the pandemic extended the distance between personal belongings. Methods We recruited 68 university students and instructed them to place their belongings on a long table following another participant (i.e., confederate). We measured the physical distance between the two belongings (i.e., the participant’s and the confederate’s). We collected data between June 10, 2022 and January 23, 2023. Pre-pandemic data was from Ariga (2016). Analysis was completed with one-tailed t-tests. Results Compared with the pre-pandemic results, via one-tailed t-test, the distance between the two belongings during the pandemic was significantly longer. Our results supported the hypothesis that the psychological framework for processing people’s belongings has dramatically changed during this pandemic. Conclusion This change may have been driven by social distancing practices or an increase in perceived vulnerability to disease. Our results provide new implications for future public spatial design, in other words, not only the distance between people, but also the distance between their belongings. " } { "@context": "http://schema.org", "@type": "BreadcrumbList", "itemListElement": [ { "@type": "ListItem", "position": "1", "item": { "@id": "https://f1000research.com/", "name": "Home" } }, { "@type": "ListItem", "position": "2", "item": { "@id": "https://f1000research.com/browse/articles", "name": "Browse" } }, { "@type": "ListItem", "position": "3", "item": { "@id": "https://f1000research.com/articles/12-199", "name": "Social distancing between personal belongings during the COVID-19..." } } ] } Home Browse Social distancing between personal belongings during the COVID-19... ALL Metrics - Views Downloads Get PDF Get XML Cite How to cite this article Guo W, Ikeda A, Takashima K et al. Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.12688/f1000research.130662.3 ) NOTE: If applicable, it is important to ensure the information in square brackets after the title is included in all citations of this article. Close Copy Citation Details Export Export Citation Sciwheel EndNote Ref. Manager Bibtex ProCite Sente EXPORT Select a format first Track Share ▬ ✚ Research Article Revised Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] Wen Guo https://orcid.org/0000-0002-5544-0033 1 , Ayumi Ikeda 1,2 , Kaito Takashima https://orcid.org/0000-0002-7489-5682 1 , [...] Yoshitaka Masuda 1 , Kohei Ueda https://orcid.org/0000-0003-1818-8366 1 , Atsunori Ariga 3 , Kyoshiro Sasaki https://orcid.org/0000-0002-5496-3748 4 , Yuki Yamada https://orcid.org/0000-0003-1431-568X 5 Wen Guo https://orcid.org/0000-0002-5544-0033 1 , Ayumi Ikeda 1,2 , [...] Kaito Takashima https://orcid.org/0000-0002-7489-5682 1 , Yoshitaka Masuda 1 , Kohei Ueda https://orcid.org/0000-0003-1818-8366 1 , Atsunori Ariga 3 , Kyoshiro Sasaki https://orcid.org/0000-0002-5496-3748 4 , Yuki Yamada https://orcid.org/0000-0003-1431-568X 5 PUBLISHED 05 Feb 2025 Author details Author details 1 Graduate School of Human-Environment Studies, Kyushu University, Fukuoka, Japan 2 Japan Society for the Promotion of Science, Tokyo, Japan 3 Faculty of letters, Chuo University, Hachioji, Japan 4 Faculty of Informatics, Kansai University, Takatsuki, Japan 5 Faculty of Arts and Science, Kyushu University, Fukuoka, Japan Wen Guo Roles: Conceptualization, Data Curation, Funding Acquisition, Investigation, Methodology, Writing – Original Draft Preparation, Writing – Review & Editing Ayumi Ikeda Roles: Conceptualization, Data Curation, Funding Acquisition, Investigation, Methodology, Resources, Visualization, Writing – Review & Editing Kaito Takashima Roles: Conceptualization, Data Curation, Formal Analysis, Funding Acquisition, Investigation, Methodology, Resources, Writing – Original Draft Preparation, Writing – Review & Editing Yoshitaka Masuda Roles: Conceptualization, Data Curation, Formal Analysis, Investigation, Methodology, Visualization, Writing – Original Draft Preparation, Writing – Review & Editing Kohei Ueda Roles: Conceptualization, Data Curation, Investigation, Methodology, Writing – Original Draft Preparation, Writing – Review & Editing Atsunori Ariga Roles: Methodology, Resources, Supervision, Writing – Review & Editing Kyoshiro Sasaki Roles: Conceptualization, Formal Analysis, Funding Acquisition, Supervision, Writing – Review & Editing Yuki Yamada Roles: Conceptualization, Data Curation, Funding Acquisition, Methodology, Project Administration, Supervision, Writing – Original Draft Preparation, Writing – Review & Editing OPEN PEER REVIEW DETAILS REVIEWER STATUS This article is included in the Emerging Diseases and Outbreaks gateway. This article is included in the Social Psychology gateway. This article is included in the Japan Institutional Gateway gateway. Abstract Background The COVID-19 pandemic has led to instructions and suggestions from governments and experts to maintain social (physical) distance between people to prevent aerosol transmission of the virus, which is now becoming the norm. Thus, we examined whether the pandemic extended the distance between personal belongings. Methods We recruited 68 university students and instructed them to place their belongings on a long table following another participant (i.e., confederate). We measured the physical distance between the two belongings (i.e., the participant’s and the confederate’s). We collected data between June 10, 2022 and January 23, 2023. Pre-pandemic data was from Ariga (2016). Analysis was completed with one-tailed t -tests. Results Compared with the pre-pandemic results, via one-tailed t -test, the distance between the two belongings during the pandemic was significantly longer. Our results supported the hypothesis that the psychological framework for processing people’s belongings has dramatically changed during this pandemic. Conclusion This change may have been driven by social distancing practices or an increase in perceived vulnerability to disease. Our results provide new implications for future public spatial design, in other words, not only the distance between people, but also the distance between their belongings. READ ALL READ LESS Keywords personal space, COVID-19, social distancing, perceived vulnerability to disease (PVD) Corresponding Author(s) Yuki Yamada ( [email protected] ) Close Corresponding author: Yuki Yamada Competing interests: No competing interests were disclosed. Grant information: This work was supported by the Japanese Psychological Association Grant for research and practical activities related to the spread of the novel coronavirus (21110) to YY; the Japanese Science and Technology Agency (JST) Support for pioneering Research Initiated by the Next Generation (SPRING) (JPMJSP2136) to WG and KT; the Japan Society for the Promotion of Science (JSPS) KAKENHI (JP19K14482) and (JP22K13881) to KS, (JP20H04581) and (JP22K18263) to YY, (JP21H03784) to KS and YY, and (JP20J21976) to A.I. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Copyright: © 2025 Guo W et al . This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. How to cite: Guo W, Ikeda A, Takashima K et al. Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.12688/f1000research.130662.3 ) First published: 20 Feb 2023, 12 :199 ( https://doi.org/10.12688/f1000research.130662.1 ) Latest published: 05 Feb 2025, 12 :199 ( https://doi.org/10.12688/f1000research.130662.3 ) Revised Amendments from Version 2 We added some new text, mainly including the clarification of the concept of personal space and the innovation of this study, as noted by the reviewers. In addition, some new prospects for future research were proposed in the discussion section. We added some new text, mainly including the clarification of the concept of personal space and the innovation of this study, as noted by the reviewers. In addition, some new prospects for future research were proposed in the discussion section. See the authors' detailed response to the review by Nur Givon-Benjio See the authors' detailed response to the review by Leon O. H Kroczek See the authors' detailed response to the review by Tomoko Isomura READ REVIEWER RESPONSES Introduction Social psychology and proxemics have long addressed personal space as the spatial range surrounding the individual ( Sommer, 1959 ; Hall, 1966 ). The space around the individual may exist in two forms. One is interpersonal distance, the area around the body that individuals maintain between themselves and others during social interactions ( Candini et al. , 2021 ). The other one is peripersonal space, which is an adaptive and flexible interface between the body and the environment, contributing to the organization of social life. For example, when this space is encroached by others, we may feel uncomfortable, or may prepare our bodies for defensive responses ( Hall, 1966 ; Coello and Cartaud, 2021 ). In our study, the concept of ‘personal space,’ as referenced later, aligns more closely with the notion of peripersonal space. This refers to the space immediately surrounding the body, within reach, centered on the individual, and typically protected from intrusion during social interactions. However, the center of personal space is oneself, but it is not restricted to the physical body; much evidence proposed that the concept of self is expanding in space and timeline. For example, the ‘cutaneous rabbit’ can be felt not only on one’s body but also on an object that one is grasping ( Miyazaki et al., 2010 ). The line of sight away from the eye can still be perceived as exerting force on the object ( Guterstam et al., 2019 ). Furthermore, the extension of body representations to objects has been observed in neuroscience ( Iriki et al., 1996 ). As a result, personal space boundaries also expand with the extension of body perception. One observed phenomenon is in some school situations where there are desk-mates; after an argument, desk-mates will avoid putting their stationery close to the other’s belongings. It is possible that people develop a tendency to recognize personal belonging as a representation of the self at an early age ( Pedersen, 1973 ). According to James (1890) , the self is the sum of all that he can call his, including all possessions, which gives him the same emotions. Briefly, we regard our possessions as part of ourselves. This intrinsic association between personal belongings and the self-forms the foundation for understanding how external objects, including tools and technologies, can become integrated into one’s sense of self, extending the boundaries of personal space. Studies on body ownership illusions suggest that the integration of external objects or virtual representations into one’s sense of self occurs through multisensory signals, highlighting the neural mechanisms underlying extended personal space ( Nilsson & Kalckert, 2021 ). Is this sense of ownership of objects related to personal space? Ariga (2016) reported that participants placed their own objects at a greater distance from the objects of those who were unfavorable. These findings suggest that individuals’ personal space extended to the space surrounding their belongings (i.e., extended personal space). The placement of such personal belongings can be considered the most significant evidence of an extension of personal space, as it shares the same characteristics with personal space ( Russell & Ward, 1982 ; Becker, 1973 ), that the variability depending on the level of familiarity with others. Moreover, recent studies have shown that object ownership influences the representation of peripersonal space. Specifically, self-owned objects within the peripersonal space are processed faster and perceived as more reachable compared to objects owned by others, suggesting an extension of peripersonal space representation around self belongings ( Lenglart et al. , 2023 ). This effect is particularly pronounced in individuals with higher interpersonal sensitivity, as their peripersonal space boundaries dynamically adapt in response to social contexts. Further supporting this perspective, Rabellino et al. (2020) highlight that peripersonal space is not only critical for physical interactions with the environment but also closely tied to bodily self-consciousness. They suggest that peripersonal space representation involves multisensory processing and serves both protective and social functions, allowing individuals to dynamically adjust to interactions with others. These findings further support the idea that ownership can extend personal space to include the area surrounding one’s possessions, reinforcing the concept of “extended personal space.” The COVID-19 pandemic has persisted for more than three years. Governments and experts have provided instructions and suggestions to maintain a certain social (physical) distance between people to prevent droplet and aerosol infection of the virus ( Yonemitsu et al., 2020 ; Yang et al., 2021 ), and this is now becoming the norm ( Yamada et al., 2021 ). Along with the research development, we know that aerosol is one of the transmission routes ( Anderson et al., 2020 ). Coronaviruses can be released into the surrounding air and exist for an extended period for long-distance transportation ( Jiang et al., 2021 ), which means that exposed people and objects may carry the coronavirus present in aerosols. Van Doremalen et al. (2020) compared the survivability of SARS-CoV-2 (leading to COVID-19) and SARS-CoV-1 on different surfaces. They found that the survival time of SARS-CoV-2 on different material surfaces ranged from a few hours to a few days; suggesting that the surface of an item can be one of the potential pathways for virus transmission. Centers for Disease Control and Prevention (CDC) Guidelines and the World Health Organization (WHO), in their information on COVID-19, also mentioned that the virus can be transmitted by direct contact with contaminated surfaces. Regardless of the purpose or function of a place, the dense gathering of many people must be avoided. Is it possible to receive such health guidance consistently and imperceptibly influence people’s social cognitive behavior? Recent studies have reported that interpersonal distance (IPD) increased during the COVID-19 pandemic ( Holt et al. , 2022 ; Iachini et al. , 2021 ), and enlarged IPD preferences were predicted to persist beyond the pandemic ( Welsch et al., 2021 ). However, it is important to note that the enlargement of IPD is not a universal phenomenon. As Iachini et al. (2021) observed, IPD increases only when subjective risk levels are high. Similarly, Givon-Benjio et al. (2024) demonstrated that subjective risk, rather than actual infection risk, predicted changes in preferred IPD. Cartaud et al. (2020) further supported this by showing that even under conditions of high actual risk, individuals’ preferred IPD remained unchanged unless subjective risk was elevated. The results of an experiment in Arabia revealed that in the post-epidemic era, 76% of the participants were already subjectively reluctant to share close physical distance or socially polite touch with others ( Khan et al., 2021 ). Responding to precautions, the external manifestation is that we have actively increased our physical distance, but in reality, personal space has also expanded accordingly. In several studies related to personal distance in COVID-19, Fini et al. (2021) showed that interpersonal distance is influenced by the perception of realistic threat measured through the COVID-19 threat. In addition, previous research proposed that not only the perception of infection will make the public practice social distancing, but the behavior of practicing social distancing is related to specific individuals as well as related to the social meaning of collective health ( Fazio et al ., 2021 ). How has the COVID-19 pandemic and countermeasures against it changed human-human and human-object interactions? Considering the findings of Ariga (2016) , one’s personal space extends to his/her belongings, leaving them with an ‘extended personal space’. The present study aimed to examine if the ‘extended personal space’ increased as well as the personal space that has been affected under the pandemic of COVID-19. The fear of infection during the COVID-19 pandemic is closely associated with interpersonal distance. Research indicates that this fear is linked to a tendency to prefer greater interpersonal distance and to underestimate interpersonal space. However, these tendencies stem from subjective perceptions of risk rather than an actual objective risk of infection ( Givon-Benjio et al. , 2024 ). On the other hand, personal belongings are more closely related to peripersonal distance. For instance, Lenglart et al. (2023) found that individuals perceive personal items as being more “within reach” compared to other objects, suggesting an expansion in the representation of peripersonal distance. Based on the Coello and Cartaud, they indicated that interpersonal and peripersonal distances are interlinked and together influence social behavior. Therefore, in this study, we innovatively combine these two concepts for the first time to explore the impact of the combination of these two forms of personal space on social actions. We initially tried to confirm that extended personal space would be larger during the COVID-19 pandemic than during pre-pandemic (i.e., before the pandemic). Maintaining a social (physical) distance from each other is valid for preventing viral infection by droplets and aerosols. Such avoidance of a close distance from other people over a long period modulates personal space ( Tootell et al., 2021 ; Welsch et al., 2021 ). Thus, if it is true that space surrounding one’s belongings is based on the interpersonal relationship of their owner ( Ariga, 2016 ), we predicted that extended personal space would be larger at the present time than at pre-pandemic (i.e., comparing extended personal space in the present time with that in Ariga’s study). Methods Pre-registration The present study was pre-registered on the Open Science Framework (OSF) prior to conducting the experiment ( Yamada et al., 2023 ). Ethical statement Ethical approval for this study was obtained from the Graduate School of Human-Environment Studies, Kyushu University (approval number:2021-030). Written informed consent was obtained from all participants prior to the experiment. Participants The experiment period was from June 10, 2022, to January 23, 2023. The students who participated in the experiment were recruited from the university. We recruited the students via some social networking services (SNS) such as Twitter and LINE. In addition, they contacted us to participate in the experiment by scanning the QR code on our recruitment poster or were directly recruited face-to-face by the experimenters on campus. The inclusion criteria were native Japanese or international students who could speak Japanese proficiently. They were paid 1000 yen to agree to participate. All participants were required to wear face masks throughout the experiment as part of standard COVID-19 precautions. As in Ariga (2016) , data were collected from equal numbers of male and female participants in each group. One of the three potential confederates (three of the authors) participated in the experiment in pairs with an external participant. Power analysis was performed using G*Power software ( Faul et al., 2007 ). We planned to perform a one-tailed t -test on the main hypothesis. There were no related studies; thus, it was difficult to estimate the effect size. In this case, adopting an unbiased effect size (i.e., medium effect size) for power analysis is widely accepted (e.g., Chen and Kao, 2012 ; Juristo and Moreno, 2003 ). Considering this and the point when the sample size of Ariga (2016) was N = 40, we performed a power analysis (Cohen’s d = 0.5, α = .05, 1-β = .80, allocation ratio N 2/ N 1 = 1.7), and consequently, the calculated sample sizes were N = 40 per group 1 and N = 68 per group 2. Therefore, we set N = 108 as the required sample size, and hence collected data from 68 participants. The pre-registered exclusion criterion was participants who did not place their own belongings on the table; their data were excluded, and additional participants were recruited until the available participants reached 68. Finally, we collected data from 70 participants; of these, two participants were excluded since they did not bring any belongings. Data from the remaining 68 (male = 34, female = 34, M = 20.9, SD = 2.2) participants were included in the analysis. All the participants provided written informed consent after a debriefing at the end of the experiment. Study design To examine our main hypothesis, we compared extended personal space before the COVID-19 pandemic (i.e., the pre-pandemic) using Ariga’s (2016) data with that during the pandemic (the present data). There was one between-participants factor in this hypothesis. In addition, to exploratorily investigate whether the data have the same tendency as Ariga (2016) , the experiment employed friendly confederate and unfriendly confederate conditions, which was a between-participants factor. Procedure The experimental setup is shown in Figure 1 . A participant entered the waiting room, where the confederate was already present, and sat next to the confederate’s chair. The distance between two chairs was roughly 30-40 cm. In the friendly condition, the confederate started to talk about the weather with the participant and then tried to continue chatting freely. However, in the unfriendly condition, the confederate ignored the participant’s conversation and sighed every 15 seconds. Then, in both conditions, the experimenter instructed the participant and the confederate to place their belongings on the table and leave the waiting room to the experimental room. The confederate put his belongings in first and then left the room. The experimenter measured the shortest distance between the two belongings and took pictures. Distance was used as the dependent variable: If both belongings were in contact, the distance was coded as 0. In the experimental room, the participants completed a fake task and a rating task of favorability for the other participant (i.e., confederate). After the experiment was completed, we asked the participants two questions: ‘Do you realize our manipulation of favorability for the confederate?’ and ‘Why did you put the belongings there?’ Figure 1. Experimental setting. Note. Left panel: A typical positioning of the belongings is depicted. In the experiment, the confederate and participant placed their personal belongings on the table sequentially (first, the confederate placed their backpack on the right side of the table every time). The experimenter measured the minimum distance between the two belongings (accurate to millimeters). Right panel: schematic representation of the experimental room. Two chairs were set up next to the room door: first, the confederate would sit on chair B and then, the participant was asked to sit on chair A, after entering the room. The table (W 60 cm × H 150 cm) for placing their belongings was facing the chairs. The width of the confederate’s belongings was about 36cm. The confederates were three graduate male students who took turns according to their schedules. Their average age was 23.6 years old (the confederate in the original experiment was a 21-years-old male). Analysis plan We planned to perform the following pre-registered analyses. Confirmatory analysis : First, as our study aims to explore the changes in expanded personal space from pre-pandemic to the pandemic, we compared our results with those of the original study ( Ariga, 2016 ), using their data. A one-tailed t -test was conducted to confirm whether the mean distance between the nearest edges of belongings ( Figure 1 , left) would be significantly longer in the present experiment (i.e., the pandemic condition) than in the original (i.e., the pre-pandemic condition). In this and subsequent analyses, the alpha level was set to α = .05 as the inference criterion. Exploratory analysis: For a manipulation check, we conducted a one-tailed t -test of the favorability scores for the confederates to confirm whether these scores would be significantly higher in the friendly condition than in the unfriendly condition. Additionally, to test whether there was a difference in the effect of interpersonal relationships on extended personal space between pre-pandemic and the pandemic, a two-way between-participants analysis of variance (ANOVA) with confederate (friendly vs. unfriendly) and experimental timing (pre-pandemic vs. pandemic) as between-participants factors on the mean distance between belongings was conducted. For ANOVA, a significant interaction between these factors would support the hypothesis that there is a difference in the effect of interpersonal relationships on extended personal space between pre-pandemic and the pandemic. Furthermore, the significant main effect of the confederate would indicate that we could have replicated the phenomenon of the original study ( Ariga, 2016 ). R 4.1.0 ( R Core Team, 2021 ) was used for all analyses in this study, and the analysis code is available at OSF ( https://osf.io/sr3x8 ). Effect size (Cohen’s d ) was calculated by effectsize package ( Ben-Shachar, Lüdecke, and Makowski, 2020 ) version 0.6.0.1. For ANOVA, we used the anovakun function ( Iseki, 2022 ) version 4.8.7. Results A total of 68 participants, 34 in the unfriendly condition (male = 17, female = 17, M = 20.83, SD = 2.22) and 34 in the friendly condition (male = 17, female = 17, M = 20.97, SD = 2.23), participated in the present study. Confirmatory analysis As pre-registered, we calculated the mean distance between the nearest edges of belongings ( Figure 2 ). Welch’s unpaired t -test showed that the mean distance was significantly longer in the pandemic condition ( M = 43.6, SD = 25.0) than in the pre-pandemic condition ( Ariga, 2016 ; M = 20.6, SD = 15.6) ( t (105.63) = 5.88, p < .001, d = 1.10). The results suggest that people place their belongings further away from others in the COVID-19 era, supporting our hypothesis. Figure 2. Violin plots and boxplots for the mean distance between belongings (pre-pandemic vs. pandemic). Note. Red circles show mean values. Exploratory analysis Next, to check whether our manipulation was successful, we calculated the mean favorability for each condition (friendly and unfriendly). Welch’s unpaired t -test showed that the friendly condition ( M = 8.21, SD = 1.43) had a significantly higher mean favorability than the unfriendly condition ( M = 5.15, SD = 1.52) ( t (65.76) = 8.54, p < .001, d = 2.07). These results suggest that the experimental manipulation was effective. In addition, we conducted an exploratory two-way between-participants ANOVA with the confederate (friendly vs. unfriendly) and experimental timing (pre-pandemic vs. pandemic) as between-participants factors on the distance between belongings ( Figure 3 ). The results showed a significant main effect of the experimental timing ( F (1, 104) = 27.39, p < .001, η G 2 = 0.21). However, neither a significant main effect of the confederate ( F (1, 104) = 1.66, p = .20, η G 2 = 0.02) nor an interaction ( F (1, 104) = 0.85, p = .36, η G 2 = 0.01) were found. These results suggest that people place more distance between their belongings and others’ in the COVID-19 era, regardless of whether the other participant (i.e., confederate) was friendly. Figure 3. Violin plots and boxplots for the mean distance between belongings (experimental timing × confederate). Note. Red circles show mean values. Discussion This study aimed to investigate whether the distance between personal belongings changed during the COVID-19 pandemic. We directly replicated the experiment on the phenomenon in which distance was governed by the interpersonal relationship between owners, called extended personal space ( Ariga, 2016 ), and explored the effect of COVID-19 on this phenomenon. Compared with the results for pre-pandemic from Ariga (2016) , the gross distance between personal belongings during the pandemic was significantly longer. The results suggest that our pre-registered hypothesis was supported; extended personal space increased during period of the COVID-19 pandemic, but we consider COVID-19 as one of the reasons for this change. The large effect size of the difference implies that the psychological framework for processing people’s own belongings changed dramatically during this pandemic. In this study, the procedure was directly repeated from the original experiment; the participants were Japanese university students, as in Ariga (2016) , which ensured that the significant increase in distance was not due to inherent differences in personal space based on ethnicity ( Hall, 1966 ) or age ( Fry and Willis, 1971 ). The two experiments differed in period (pre-pandemic vs. pandemic). Participants in this study were university students who were under the COVID-19 pandemic during their university years; they were required to maintain social distance and avoid unnecessary outings. Maintaining social distancing means reducing or minimizing human interactions ( Wilder-Smith and Freedman, 2020 ). Several studies have confirmed the increase in personal space during the COVID-19 pandemic and suggested the practice of social distancing attributed to the increase ( Fini, Tummolini, and Borghi, 2021 ; Fazio et al., 2021 ). Moreover, our study found that the distance between objects increased during the pandemic. Recent findings from studies on the psychological impact of the COVID-19 pandemic provide additional support for our findings. For example, Serino et al. (2021) demonstrated that the pandemic led to a sharpening of peripersonal space boundaries, with individuals adapting their spatial perceptions in response to increased health-related concerns. This phenomenon aligns with our observation that the distance between personal belongings increased during the pandemic. The findings suggest that participants might have subconsciously extended their spatial boundaries to maintain greater safety and reduce perceived risks associated with potential contamination. This adaptation, as highlighted by Serino et al. (2021) , may explain why people positioned their belongings farther away from other’s during the pandemic. Considering Ariga (2016) , personal belongings have the same personal space-like properties as the owner, belongings also maintain their social distance when they are placed. This distance could manifest in the elongated distance of personal belongings. One possibility is that the participants recognized the confederate and their belonging as carriers of an infectious disease. In Japan, perceived vulnerability to disease (PVD) has increased during the COVID-19 pandemic compared to pre-pandemic era ( Yonemitsu et al., 2020 ), and the perceived risk of COVID-19 infection is associated with increased personal space ( Holt et al., 2022 ). Since personal belongings also can be the source of infection through aerosols, the perceived risk of infection may extend to them. It is precisely due to the increased subjective perception of risk that, in the context of COVID-19, the extension of personal belongings comes to represent the characteristics of personal space, and the distance between personal belongings also increases. Participants without sufficient prior information could place their belongings at a distance from the confederate’s belongings to avoid contamination as they were unsure whether the stranger and their belongings were infected with viruses. Moreover, some previous studies declared that the confined spaces may enhance the feeling of personal space invasion, thereby increasing psychological stress and anxiety ( Aiello et al ., 1977 ; Evans, & Wener, 2007 ). In the present study, for strict replication and fair comparison, the chair distance was set to be the same as in the original experiment conducted in the pre-pandemic period, but the small distance between chairs may have created a sense of social anxiety and constriction at the beginning, making participants place belongings farther away to alleviate seated proximity in subsequent place sessions. No studies that have been done to illustrate the effect of physical proximity on the unraveling of the distance between items. Another possibility is that participants tried to be compliant. In the US, a 1% increase in new cases (deaths) in the last seven days is associated with a 3% (11%) increase in social distancing intensity ( Besley and Dray, 2022 ). In Japan, the number of cases and deaths is reported daily in the news which could maintain a high level of compliance (i.e., willingness to distance themselves socially). In fact, all valid participants in this study voluntarily wore face masks, which is a routine infection control measure. Beyond compliance, mask-wearing might have also influenced the observed spatial distancing behavior. Research has shown that wearing face masks can alter interpersonal perceptions and decrease interpersonal and peripersonal distances in certain contexts. For example, Cartaud et al. (2020) found that individuals perceived as wearing face masks are considered more trustworthy, leading to reduced physical distance. Similarly, Biggio et al. (2022) reported that mask-wearing shapes interpersonal space by fostering a sense of safety and reducing the need for extended spatial boundaries. In our study, while participants wore face masks during the experiment, the observed increase in distance between personal belongings suggests that compliance with infection control measures and risk-avoidance behaviors might interact differently when participants place objects instead of interacting directly with people. We speculated that participants may have maintained a distance between belongings to ensure compliance. This compliance-based explanation can coexist independently with the above explanation of infection avoidance. Intriguingly, our study did not find a significant effect of the confederate’s friendliness on participants’ behavior, as indicated by the lack of a significant interaction effect in the ANOVA. This result appears to be inconsistent with the findings from Ariga (2016) . One possible explanation for this discrepancy could be a ceiling effect, where participants’ behavior might have already reached its peak, limiting the observable impact of additional friendliness. In other words, the width of the desk (150 cm) was long enough in the pre-pandemic period ( Ariga, 2016 ), but may have been too short to study the effect of the confederate during the pandemic period (see Figure 1 ). Although the confederate experimenters tried to place their belongings as far as possible to the left corner of the desks, the space left to the participants was estimated to be about 110 cm. The size of 110 cm minus each participant’s belongings was the maximum distance that the participant could set. The distribution of the data in terms of the COVID-19 pandemic reached close to this maximum distance. If the desks were much longer, participants would have been able to place their belongings at a distance from the unfriendly person’s belongings without worrying about the risk of their belongings falling off. The replicability of the original phenomenon in the confederate itself needs to be confirmed by more replication studies. Although there is a large difference between the present study and Ariga (2016) in terms of the COVID-19 pandemic, other potential differences could have existed as hidden moderators, which might have impacted the results. For example, Rissho University, where the Ariga (2016) experiment was conducted, is in Tokyo, while Kyushu University, where we conducted the present study, is in the deep mountainous countryside. Many of the students at Rissho University, the sample from which the pre-pandemic data was generated, use fully crowded trains to commute to campus every day, possibly affecting one’s personal space. In addition, about a decade has passed since Ariga’s (2016) data collection and the present study. Therefore, we should consider that changes, unrelated to the pandemic, might have occurred in the long term. For example, in the 2010s, smartphones became widespread in Japan, and hence, social media and social networking services (SNS) have greatly developed ( Ministry of Internal Affairs and Communications, 2017 ). Although this is just a speculation, the distance for social interaction may have changed over time, as such communication without the effect of physical distance from the other person becomes mainstream. This issue can be addressed in the future by examining the relationship between personal spaces and SNS use. In addition, it would be important to consider other factors such as mood, interpersonal anxiety, and other person-related characteristics. To dissociate the factor of the pandemic from other potential factors, conducting the study using the same procedure again after the pandemic would be effective. Additionally, future studies should further examine how interpersonal and peripersonal distances interact in different contexts. For example, the level of perceived infectability (i.e., beliefs about one’s own susceptibility to infectious diseases) in 2023 has dropped to the same level as before the COVID-19 pandemic in Japan ( Ikeda et al. , 2024 ). Although the number of diagnosed COVID-19 cases remains high, people’s subjective risk perception has declined. The potential changes in sensitivity suggested by such reports provide us with numerous possibilities for discussion. Would the effect still emerge when the perceived risk of infection is low? Additionally, would it manifest if participants were asked to place items they do not own? Alternatively, the persistence of the effect—despite the lack of influence of the confederate’s friendliness—suggests that the expansion of peripersonal space during the pandemic might be independent of social cues. Furthermore, the perception of distance may be shaped by long-term societal and technological changes. The widespread use of smartphones and social media in the 2010s might have altered norms around physical proximity and social interaction. Future research could investigate whether personal space norms adapt to such technological shifts and how these changes interact with interpersonal and peripersonal distances. If future research compares the data of Ariga (2016) , the present research, and future research, such as a single case design (i.e., ABA design), they can extract the impact of the COVID-19 pandemic to our personal space more clearly than our study. Alternatively, examining the association between the impact and individual differences in disgust proneness ( Haidt, McCauley, and Rozin, 1994 ; Curtis, De Barra, and Aunger, 2011 ) or compliance ( Zajenkowski et al., 2020 ) might be helpful. This pandemic has inspired researchers worldwide, and too many papers were published ( Pai, 2020 ). However, it is essential to reverify scientific knowledge, including our study, in the post-COVID-19 era. This should lead to strong knowledge in preparation for the next pandemic. Conclusion In summary, this study examined expanded personal space during the COVID-19 pandemic. Personal space is modulated by several factors including gender, personality traits ( Khmiliar et al., 2020 ), mental status ( Park et al., 2009 ; Schoretsanitis et al., 2016 ; Kennedy et al. , 2009 ), and social function (e.g., social cognition; Holt et al., 2015 ). The distance of personal space serves as a mechanism to avoid disease when the body is threatened by a virus ( Park, 2015 ). Thus, specific conditions in which the threat of infection is extremely high, such as the COVID-19 pandemic, could motivate people to place belongings at increasing distances from others. Although the present study could not clarify the mechanism of this phenomenon and has several limitations discussed above, the results show that people significantly increased, with a large effect size, the distance between personal belongings during the COVID-19 pandemic. It is important to note, however, that the results of the present experiment do not fully demonstrate that COVID-19 was the only factor that affected the expanded personal space between belongings. Without regard to personal favorability, the distance between personal belongings now is already twice as great as that in pre-pandemic. Our results provide new insights into future spatial design of public spaces. Not only the social distance between people’s seats but also personal belongings need their ‘own space’ in open places. For example, but not limited to, lockers (or shelving) in gyms and large public baths should be increased in space to ensure the psychological safety and comfort of users. Data availability Underlying data Open Science Framework: The influence of the COVID-19 pandemic on personal space extends to belonging ( https://doi.org/10.17605/OSF.IO/SR3X8 ) ( Guo et al., 2023 ). This project contains the following underlying data: • Analysis code. (Analysis for t -tests and ANOVA of data). • Raw data.csv (Measurements of distance between each participant and confederate’s belongings for friendly and unfriendly settings for current study and Agriga 2016 data). • Picture of the distance between the two belongings.zip. (Pictures of belongings in friendly and unfriendly settings.) Data are available under the terms of the Creative Commons Attribution 4.0 International license (CC-BY 4.0). References Aiello JR, DeRisi DT, Epstein YM, et al. : Crowding and the role of interpersonal distance preference. Sociometry. 1977; 40 (3): 271–282. Publisher Full Text Anderson EL, Turnham P, Griffin JR, et al. : Consideration of the aerosol transmission for COVID-19 and public health. Risk Anal. 2020; 40 (5): 902–907. PubMed Abstract | Publisher Full Text | Free Full Text Ariga A: Expansive personal space: Distance between personal belongings reflects the interpersonal distance of their owners. Japanese J. Psychol. 2016; 87 : 186–190. PubMed Abstract | Publisher Full Text Becker FD: Study of spatial markers. J. Pers. Soc. Psychol. 1973; 26 : 439–445. Publisher Full Text Ben-Shachar MS, Lüdecke D, Makowski D: effectsize: Estimation of Effect Size Indices and Standardized Parameters. J. Open Source Softw. 2020; 5 (56): 2815. Publisher Full Text Besley T, Dray S: Pandemic responsiveness: Evidence from social distancing and lockdown policy during COVID-19. PLoS One. 2022; 17 (5): e0267611. PubMed Abstract | Publisher Full Text | Free Full Text Biggio M, Bisio A, Bruno V, et al. : Wearing a mask shapes interpersonal space during COVID-19 pandemic. Brain Sci. 2022; 12 (5): 682. PubMed Abstract | Publisher Full Text | Free Full Text Candini M, Battaglia S, Benassi M, et al. : The physiological correlates of interpersonal space. Sci. Rep. 2021; 11 (1): 2611. PubMed Abstract | Publisher Full Text | Free Full Text Cartaud A, Quesque F, Coello Y: Wearing a face mask against COVID-19 results in a reduction of social distancing. PLoS One. 2020; 15 (12): e0243023. PubMed Abstract | Publisher Full Text | Free Full Text Chen H, Kao LS: Success in academic surgery: Part 1. Springer Science & Business Media; 2012. Publisher Full Text Coello Y, Cartaud A: The interrelation between peripersonal action space and interpersonal social space: Psychophysiological evidence and clinical implications. Front. Hum. Neurosci. 2021; 15 : 636124. PubMed Abstract | Publisher Full Text | Free Full Text Curtis V, De Barra M, Aunger R: Disgust as an adaptive system for disease avoidance behaviour. Philos. Trans. R. Soc. Lond., B, Biol. Sci. 2011; 366 (1563): 389–401. PubMed Abstract | Publisher Full Text | Free Full Text Evans GW, Wener RE: Crowding and personal space invasion on the train: Please don’t make me sit in the middle. J. Environ. Psychol. 2007; 27 (1): 90–94. Publisher Full Text Faul F, Erdfelder E, Lang AG, et al. : G*Power 3: A flexible statistical power analysis program for the social, behavioral, and biomedical sciences. Behav. Res. Methods. 2007; 39 : 175–191. PubMed Abstract | Publisher Full Text Fazio RH, Ruisch BC, Moore CA, et al. : Social distancing decreases an individual’s likelihood of contracting COVID-19. Proc. Natl. Acad. Sci. 2021; 118 (8): e2023131118. PubMed Abstract | Publisher Full Text | Free Full Text Fini C, Tummolini L, Borghi AM: Contextual modulation of preferred social distance during the Covid-19 pandemic. Sci. Rep. 2021; 11 : 23726. PubMed Abstract | Publisher Full Text | Free Full Text Fry AM, Willis FN: Invasion of personal space as a function of the age of the invader. Psychol. Rec. 1971; 21 (3): 385–389. Publisher Full Text Givon-Benjio N, Sokolover H, Aderka IM, et al. : Perception of interpersonal distance and social distancing before and during COVID-19 pandemic. Sci. Rep. 2024; 14 (1): 4568. PubMed Abstract | Publisher Full Text | Free Full Text Guo W, Ikeda A, Takashima K, et al. : The influence of the COVID-19 pandemic on personal space extends to belonging.2023, February 11. Publisher Full Text Guterstam A, Kean HH, Webb TW, et al. : Implicit model of other people’s visual attention as an invisible, force-carrying beam projecting from the eyes. Proc. Natl. Acad. Sci. 2019; 116 (1): 328–333. PubMed Abstract | Publisher Full Text | Free Full Text Haidt J, McCauley C, Rozin P: Individual differences in sensitivity to disgust: A scale sampling seven domains of disgust elicitors. Personal. Individ. Differ. 1994; 16 (5): 701–713. Publisher Full Text Hall ET: The hidden dimension. Anchor; 1966; vol. 609 . . Holt DJ, Boeke EA, Coombs G III, et al. : Abnormalities in personal space and parietal–frontal function in schizophrenia. NeuroImage: Clinical. 2015; 9 : 233–243. PubMed Abstract | Publisher Full Text | Free Full Text Holt DJ, Zapetis SL, Babadi B, et al. : Personal space increases during the COVID-19 pandemic in response to real and virtual humans. Front. Psychol. 2022; 13 : 952998. PubMed Abstract | Publisher Full Text | Free Full Text Iachini T, Frassinetti F, Ruotolo F, et al. : Social Distance during the COVID-19 Pandemic Reflects Perceived Rather than Actual Risk. Int. J. Environ. Res. Public. Health. 2021; 18 :5504. PubMed Abstract | Publisher Full Text | Free Full Text Ikeda A, Sasaki K, Yamada Y: Evolution of perceived vulnerability to infection in Japan during the COVID-19 pandemic. Qeios. 2024; 6 . Publisher Full Text Iriki A, Tanaka M, Iwamura Y: Coding of modified body schema during tool use by macaque postcentral neurones. Neuroreport. 1996; 7 : 2325–2330. PubMed Abstract | Publisher Full Text Iseki R: anovakun.2022. Retrieved December 4, 2022. Reference Source James W: The principles of psychology. New York, NY: Holt; 1890. Jiang G, Wang C, Song L, et al. : Aerosol transmission, an indispensable route of COVID-19 spread: Case study of a department-store cluster. Front. Environ. Sci. Eng. 2021; 15 (3): 12–46. PubMed Abstract | Publisher Full Text | Free Full Text Juristo N, Moreno AM: Lecture Notes on Empirical Software Engineering. World Scientific; 2003. Kennedy DP, Gläscher J, Tyszka JM, et al. : Personal space regulation by the human amygdala. Nat. Neurosci. 2009; 12 (10): 1226–1227. PubMed Abstract | Publisher Full Text | Free Full Text Khan SQ, Al-Humaid J, Farooqi FA, et al. : The post-pandemic era: will physical distancing be a perceived way of life? F1000Res. 2021; 10 : 1090. PubMed Abstract | Publisher Full Text | Free Full Text Khmiliar О, Popovych I, Hrys A, et al. : Spatial regulation of personal behavior under conditions of the accelerating covid-19 pandemic. Revista Inclusiones. 2020; 289–306. Lenglart L, Cartaud A, Quesque F, et al. : Object coding in peripersonal space depends on object ownership. Q. J. Exp. Psychol. 2023; 76 (8): 1925–1939. PubMed Abstract | Publisher Full Text Ministry of Internal Affairs and Communications: Advent of the smart phone society. 2017. Reference Source Miyazaki M, Hirashima M, Nozaki D: The “cutaneous rabbit” hopping out of the body. J. Neurosci. 2010; 30 (5): 1856–1860. PubMed Abstract | Publisher Full Text | Free Full Text Nilsson M, Kalckert A: Region-of-interest analysis approaches in neuroimaging studies of body ownership: An activation likelihood estimation meta-analysis. Eur. J. Neurosci. 2021; 54 (11): 7974–7988. PubMed Abstract | Publisher Full Text Pai M: Covidization of research: What are the risks? Nat. Med. 2020; 26 (8): 1159. PubMed Abstract | Publisher Full Text Park JH: Introversion and human-contaminant disgust sensitivity predict personal space. Personal. Individ. Differ. 2015; 82 : 185–187. Publisher Full Text Park SH, Ku J, Kim JJ, et al. : Increased personal space of patients with schizophrenia in a virtual social environment. Psychiatry Res. 2009; 169 (3): 197–202. PubMed Abstract | Publisher Full Text Pedersen DM: Developmental trends in personal space. J. Psychol. 1973; 83 (1): 3–9. PubMed Abstract | Publisher Full Text R Core Team: R: A language and environment for statistical computing. Vienna, Austria: R Foundation for Statistical Computing; 2021. Reference Source Rabellino D, Frewen PA, McKinnon MC, et al. : Peripersonal space and bodily self-consciousness: implications for psychological trauma-related disorders. Front. Neurosci. 2020; 14 : 586605. PubMed Abstract | Publisher Full Text | Free Full Text Russell JA, Ward LM: Environmental psychology. Annu. Rev. Psychol. 1982; 33 : 651–689. Publisher Full Text Schoretsanitis G, Kutynia A, Stegmayer K, et al. : Keep at bay! Abnormal personal space regulation as marker of paranoia in schizophrenia. Eur. Psychiatry. 2016; 31 : 1–7. PubMed Abstract | Publisher Full Text Serino S, Trabanelli S, Jandus C, et al. : Sharpening of peripersonal space during the COVID-19 pandemic. Curr. Biol. 2021; 31 (14):R889–R890. PubMed Abstract | Publisher Full Text | Free Full Text Sommer R: Studies in personal space. Sociometry. 1959; 22 (3): 247–260. Publisher Full Text Tootell RB, Zapetis SL, Babadi B, et al. : Psychological and physiological evidence for an initial ‘Rough Sketch’ calculation of personal space. Sci. Rep. 2021; 11 (1): 20915–20960. PubMed Abstract | Publisher Full Text | Free Full Text Van Doremalen N, Bushmaker T, Morris DH, et al. : Aerosol and surface stability of SARS-CoV-2 as compared with SARS-CoV-1. N. Engl. J. Med. 2020; 382 (16):1564–1567. PubMed Abstract | Publisher Full Text | Free Full Text Welsch R, Wessels M, Bernhard C, et al. : Physical distancing and the perception of interpersonal distance in the COVID-19 crisis. Sci. Rep. 2021; 11 (1): 11485–11489. PubMed Abstract | Publisher Full Text | Free Full Text Wilder-Smith A, Freedman DO: Isolation, quarantine, social distancing and community containment: Pivotal role for old-style public health measures in the novel coronavirus (2019-nCoV) outbreak. J. Travel Med. 2020; 27 (2): taaa020. PubMed Abstract | Publisher Full Text | Free Full Text Yamada Y, Ikeda A, Takashima K, et al. : The influence of COVID-19 pandemic on the personal space extended to belongings.2023, February 1. Publisher Full Text Yamada Y, Ćepulić D-B, Coll-Martín T, et al. : COVIDiSTRESS Global Survey dataset on psychological and behavioural consequences of the COVID-19 outbreak. Scientific Data. 2021; 8 (1): 3. PubMed Abstract | Publisher Full Text | Free Full Text Yang J, Wu X, Sasaki K, et al. : No significant association of repeated messages with changes in health compliance in the COVID-19 pandemic: A registered report on the extended parallel process model. PeerJ. 2021; 9 : e11559. PubMed Abstract | Publisher Full Text | Free Full Text Yonemitsu F, Ikeda A, Yoshimura N, et al. : Warning ‘Don’t spread’ versus ‘Don’t be a spreader’ to prevent the COVID-19 pandemic. R. Soc. Open Sci. 2020; 7 (9): 200793. PubMed Abstract | Publisher Full Text | Free Full Text Zajenkowski M, Jonason PK, Leniarska M, et al. : Who complies with the restrictions to reduce the spread of COVID-19? Personality and perceptions of the COVID-19 situation. Personal. Individ. Differ. 2020; 166 : 110199. PubMed Abstract | Publisher Full Text | Free Full Text Comments on this article Comments (0) Version 3 VERSION 3 PUBLISHED 20 Feb 2023 ADD YOUR COMMENT Comment Author details Author details 1 Graduate School of Human-Environment Studies, Kyushu University, Fukuoka, Japan 2 Japan Society for the Promotion of Science, Tokyo, Japan 3 Faculty of letters, Chuo University, Hachioji, Japan 4 Faculty of Informatics, Kansai University, Takatsuki, Japan 5 Faculty of Arts and Science, Kyushu University, Fukuoka, Japan Wen Guo Roles: Conceptualization, Data Curation, Funding Acquisition, Investigation, Methodology, Writing – Original Draft Preparation, Writing – Review & Editing Ayumi Ikeda Roles: Conceptualization, Data Curation, Funding Acquisition, Investigation, Methodology, Resources, Visualization, Writing – Review & Editing Kaito Takashima Roles: Conceptualization, Data Curation, Formal Analysis, Funding Acquisition, Investigation, Methodology, Resources, Writing – Original Draft Preparation, Writing – Review & Editing Yoshitaka Masuda Roles: Conceptualization, Data Curation, Formal Analysis, Investigation, Methodology, Visualization, Writing – Original Draft Preparation, Writing – Review & Editing Kohei Ueda Roles: Conceptualization, Data Curation, Investigation, Methodology, Writing – Original Draft Preparation, Writing – Review & Editing Atsunori Ariga Roles: Methodology, Resources, Supervision, Writing – Review & Editing Kyoshiro Sasaki Roles: Conceptualization, Formal Analysis, Funding Acquisition, Supervision, Writing – Review & Editing Yuki Yamada Roles: Conceptualization, Data Curation, Funding Acquisition, Methodology, Project Administration, Supervision, Writing – Original Draft Preparation, Writing – Review & Editing Competing interests No competing interests were disclosed. Grant information This work was supported by the Japanese Psychological Association Grant for research and practical activities related to the spread of the novel coronavirus (21110) to YY; the Japanese Science and Technology Agency (JST) Support for pioneering Research Initiated by the Next Generation (SPRING) (JPMJSP2136) to WG and KT; the Japan Society for the Promotion of Science (JSPS) KAKENHI (JP19K14482) and (JP22K13881) to KS, (JP20H04581) and (JP22K18263) to YY, (JP21H03784) to KS and YY, and (JP20J21976) to A.I. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Article Versions (3) version 3 Revised Published: 05 Feb 2025, 12:199 https://doi.org/10.12688/f1000research.130662.3 version 2 Revised Published: 27 Aug 2024, 12:199 https://doi.org/10.12688/f1000research.130662.2 version 1 Published: 20 Feb 2023, 12:199 https://doi.org/10.12688/f1000research.130662.1 Copyright © 2025 Guo W et al . This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Download Export To Sciwheel Bibtex EndNote ProCite Ref. Manager (RIS) Sente metrics Views Downloads F1000Research - - PubMed Central info_outline Data from PMC are received and updated monthly. - - Citations open_in_new 0 open_in_new 0 open_in_new SEE MORE DETAILS CITE how to cite this article Guo W, Ikeda A, Takashima K et al. Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.12688/f1000research.130662.3 ) NOTE: If applicable, it is important to ensure the information in square brackets after the title is included in all citations of this article. COPY CITATION DETAILS track receive updates on this article Track an article to receive email alerts on any updates to this article. TRACK THIS ARTICLE Share Open Peer Review Current Reviewer Status: ? Key to Reviewer Statuses VIEW HIDE Approved The paper is scientifically sound in its current form and only minor, if any, improvements are suggested Approved with reservations A number of small changes, sometimes more significant revisions are required to address specific details and improve the papers academic merit. Not approved Fundamental flaws in the paper seriously undermine the findings and conclusions Version 3 VERSION 3 PUBLISHED 05 Feb 2025 Revised Views 0 Cite How to cite this report: Isomura T. Reviewer Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.177402.r364741 ) The direct URL for this report is: https://f1000research.com/articles/12-199/v3#referee-response-364741 NOTE: it is important to ensure the information in square brackets after the title is included in this citation. Close Copy Citation Details Reviewer Report 17 Feb 2025 Tomoko Isomura , Graduate School of Informatics, Nagoya University, Nagoya, Japan Approved with Reservations VIEWS 0 https://doi.org/10.5256/f1000research.177402.r364741 I sincerely apologize for my delayed response due to issues with receiving notifications. I appreciate the authors' efforts in addressing my concerns. One thing I am still wondering about is their raw data. While ... Continue reading READ ALL I sincerely apologize for my delayed response due to issues with receiving notifications. I appreciate the authors' efforts in addressing my concerns. One thing I am still wondering about is their raw data. While the authors mentioned that there are 68 data after excluding two participants who did not bring any belongings, I found that the raw data includes all 70 participants with "distance" data. What do the distance data from these two participants represent then? I have no further concerns beyond this. Competing Interests: No competing interests were disclosed. Reviewer Expertise: experimental psychology; embodied cognition; social cognition I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above. Close READ LESS CITE CITE HOW TO CITE THIS REPORT Isomura T. Reviewer Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.177402.r364741 ) The direct URL for this report is: https://f1000research.com/articles/12-199/v3#referee-response-364741 NOTE: it is important to ensure the information in square brackets after the title is included in all citations of this article. COPY CITATION DETAILS Report a concern Author Response 10 Mar 2025 Kaito Takashima , Graduate School of Human-Environment Studies, Kyushu University, Fukuoka, Japan 10 Mar 2025 Author Response We apologize for not describing this clearly. Two participants did not bring any personal belongings with them, but they took our flyer at the reception desk and placed them on ... Continue reading We apologize for not describing this clearly. Two participants did not bring any personal belongings with them, but they took our flyer at the reception desk and placed them on the table during the experiment, so we also measured the distance according to the experimental procedures. However, the flyer could not be counted as personal belongings. Therefore, even though we obtained these two participants’ data, we excluded the data of these two considering the definition of personal belongings in the experimental purpose. We apologize for not describing this clearly. Two participants did not bring any personal belongings with them, but they took our flyer at the reception desk and placed them on the table during the experiment, so we also measured the distance according to the experimental procedures. However, the flyer could not be counted as personal belongings. Therefore, even though we obtained these two participants’ data, we excluded the data of these two considering the definition of personal belongings in the experimental purpose. Competing Interests: No competing interests were disclosed. Close Report a concern Respond or Comment COMMENTS ON THIS REPORT Author Response 10 Mar 2025 Kaito Takashima , Graduate School of Human-Environment Studies, Kyushu University, Fukuoka, Japan 10 Mar 2025 Author Response We apologize for not describing this clearly. Two participants did not bring any personal belongings with them, but they took our flyer at the reception desk and placed them on ... Continue reading We apologize for not describing this clearly. Two participants did not bring any personal belongings with them, but they took our flyer at the reception desk and placed them on the table during the experiment, so we also measured the distance according to the experimental procedures. However, the flyer could not be counted as personal belongings. Therefore, even though we obtained these two participants’ data, we excluded the data of these two considering the definition of personal belongings in the experimental purpose. We apologize for not describing this clearly. Two participants did not bring any personal belongings with them, but they took our flyer at the reception desk and placed them on the table during the experiment, so we also measured the distance according to the experimental procedures. However, the flyer could not be counted as personal belongings. Therefore, even though we obtained these two participants’ data, we excluded the data of these two considering the definition of personal belongings in the experimental purpose. Competing Interests: No competing interests were disclosed. Close Report a concern COMMENT ON THIS REPORT Views 0 Cite How to cite this report: Miyazaki G. Reviewer Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.177402.r365484 ) The direct URL for this report is: https://f1000research.com/articles/12-199/v3#referee-response-365484 NOTE: it is important to ensure the information in square brackets after the title is included in this citation. Close Copy Citation Details Reviewer Report 17 Feb 2025 Genta Miyazaki , Gakushuin University, Tokyo, Japan Approved with Reservations VIEWS 0 https://doi.org/10.5256/f1000research.177402.r365484 Summary: This pre-registered study examined whether individuals placed their personal belongings at a greater distance from others’ belongings during the COVID-19 pandemic than before. The authors compared experimental results from the COVID-19 pandemic with those from the pre-pandemic (Ariga, ... Continue reading READ ALL Summary: This pre-registered study examined whether individuals placed their personal belongings at a greater distance from others’ belongings during the COVID-19 pandemic than before. The authors compared experimental results from the COVID-19 pandemic with those from the pre-pandemic (Ariga, 2016). They found that personal belongings were spaced farther during the pandemic than before. The authors interpreted these findings as suggesting that as personal space expanded during the COVID-19 pandemic, the extended personal space, represented by the distance between belongings, also increased. Review: This study is valuable because it carefully replicates the experimental procedures of the previous research (Ariga, 2016 [Ref-1]). Furthermore, it provides crucial data on extended personal spaces during the COVID-19 pandemic. However, as the authors acknowledged in their discussion, the present study did not provide definitive evidence that the observed differences were caused directly by the COVID-19 pandemic. It may be helpful to analyze the responses to the question, "Why did you put the belongings there?" as measured in the present study, to address this limitation. How many participants indicated concerns about COVID-19 or adherence to social distancing? This analysis could help reinforce the interpretation of the authors’ findings. In a previous study (Ariga, 2016 [Ref-1]), responses to the same question were analyzed. This revealed that among the 20 participants in the unfriendly condition, 16 stated that they placed their bags away from the confederate’s bag because they did not want to put their belongings close to it. This suggests that the participants could verbalize their reasons for maintaining distance between their belongings and those of the confederate. Minor Points: The variance in the distance between belongings appeared to be greater during the pandemic than during the pre-pandemic period. Please provide an interpretation of this result. The manuscript states, "Intriguingly, our study did not find a significant effect of the confederate’s friendliness on participants’ behavior, as indicated by the lack of a significant interaction effect in the ANOVA" (p. 9). However, if the present experiment observed an effect of the confederate’s friendliness similar to that in Ariga (2016 [Ref-1]), an interaction should not have been expected. Instead of stating "the lack of a significant interaction effect," the sentence should refer to "the lack of a significant main effect of the confederate’s friendliness". Is the work clearly and accurately presented and does it cite the current literature? Yes Is the study design appropriate and is the work technically sound? Partly Are sufficient details of methods and analysis provided to allow replication by others? Yes If applicable, is the statistical analysis and its interpretation appropriate? Yes Are all the source data underlying the results available to ensure full reproducibility? Yes Are the conclusions drawn adequately supported by the results? Partly References 1. Ariga A: [Expansive personal space: Distance between personal belongings reflects the interpersonal distance of their owners]. Shinrigaku Kenkyu . 2016; 87 (2): 186-90 PubMed Abstract | Publisher Full Text Competing Interests: No competing interests were disclosed. Reviewer Expertise: social psychology; interpersonal relationships I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above. Close READ LESS CITE CITE HOW TO CITE THIS REPORT Miyazaki G. Reviewer Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.177402.r365484 ) The direct URL for this report is: https://f1000research.com/articles/12-199/v3#referee-response-365484 NOTE: it is important to ensure the information in square brackets after the title is included in all citations of this article. COPY CITATION DETAILS Report a concern Respond or Comment COMMENT ON THIS REPORT Views 0 Cite How to cite this report: Givon-Benjio N. Reviewer Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.177402.r364740 ) The direct URL for this report is: https://f1000research.com/articles/12-199/v3#referee-response-364740 NOTE: it is important to ensure the information in square brackets after the title is included in this citation. Close Copy Citation Details Reviewer Report 12 Feb 2025 Nur Givon-Benjio , University of Haifa, Haifa, Israel Approved VIEWS 0 https://doi.org/10.5256/f1000research.177402.r364740 The authors have thoroughly ... Continue reading READ ALL The authors have thoroughly addressed all of my concerns. Competing Interests: No competing interests were disclosed. Reviewer Expertise: Interpersonal distance (preference, perception) in COVID-19 as well as in clinical populations (social anxiety, autism). I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard. Close READ LESS CITE CITE HOW TO CITE THIS REPORT Givon-Benjio N. Reviewer Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.177402.r364740 ) The direct URL for this report is: https://f1000research.com/articles/12-199/v3#referee-response-364740 NOTE: it is important to ensure the information in square brackets after the title is included in all citations of this article. COPY CITATION DETAILS Report a concern Respond or Comment COMMENT ON THIS REPORT Views 0 Cite How to cite this report: Kroczek LOH. Reviewer Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.177402.r364739 ) The direct URL for this report is: https://f1000research.com/articles/12-199/v3#referee-response-364739 NOTE: it is important to ensure the information in square brackets after the title is included in this citation. Close Copy Citation Details Reviewer Report 12 Feb 2025 Leon O. H Kroczek , University of Regensburg, Regensburg, Germany Approved VIEWS 0 https://doi.org/10.5256/f1000research.177402.r364739 The authors have responded to all of my comments. This includes more details with respect to the experimental setting ... Continue reading READ ALL The authors have responded to all of my comments. This includes more details with respect to the experimental setting and a more nuanced discussion of the results with respect to other factors which might have driven the effect. Competing Interests: No competing interests were disclosed. Reviewer Expertise: interpersonal distance, socio-affective behavior I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard. Close READ LESS CITE CITE HOW TO CITE THIS REPORT Kroczek LOH. Reviewer Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.177402.r364739 ) The direct URL for this report is: https://f1000research.com/articles/12-199/v3#referee-response-364739 NOTE: it is important to ensure the information in square brackets after the title is included in all citations of this article. COPY CITATION DETAILS Report a concern Respond or Comment COMMENT ON THIS REPORT Version 2 VERSION 2 PUBLISHED 27 Aug 2024 Revised Views 0 Cite How to cite this report: Givon-Benjio N. Reviewer Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.170298.r348889 ) The direct URL for this report is: https://f1000research.com/articles/12-199/v2#referee-response-348889 NOTE: it is important to ensure the information in square brackets after the title is included in this citation. Close Copy Citation Details Reviewer Report 31 Dec 2024 Nur Givon-Benjio , University of Haifa, Haifa, Israel Approved with Reservations VIEWS 0 https://doi.org/10.5256/f1000research.170298.r348889 The current study examined changes in the distance at which people placed their belongings before and after the COVID-19 outbreak in Japan. The authors employed an ecological task simulating a real-life scenario. The results suggest that the pandemic predicted an ... Continue reading READ ALL The current study examined changes in the distance at which people placed their belongings before and after the COVID-19 outbreak in Japan. The authors employed an ecological task simulating a real-life scenario. The results suggest that the pandemic predicted an enlargement (or expansion) of the distance people placed their belongings from those of a confederate. This effect was not explained by whether the confederate was friendly or hostile, nor by a time*confederate interaction. Overall, I found the study very interesting and with the potential to make a meaningful contribution to existing knowledge. However, there are several areas that warrant further clarification and consideration: 1. A clear distinction should be made between interpersonal distance, which refers to the space between people (as discussed by Hall), and peripersonal distance, the space immediately surrounding the body within reach (as explored by Coello and Cartaud). This differentiation is critical for framing the study's context. The fear of infection during the COVID-19 pandemic is primarily linked to interpersonal distance. Studies have shown that fear of infection correlates with a preference for greater interpersonal distance and an underestimation of interpersonal space. However, these effects are tied to subjective perceptions of risk rather than objective risk of infection (Givon-Benjio et al., 2024). On the other hand, personal belongings conceptually align more with peripersonal distance. For example, Lenglart et al. (2023) demonstrated that personal items are perceived as more "within reach" compared to other objects, indicating an expansion of peripersonal distance representation. The paper by Coello and Cartaud (2021), cited in the introduction, suggests that interpersonal and peripersonal distances are interlinked and together influence social behavior. I recommend moving this discussion to the end of the paragraph, after clarifying the distinction between the two concepts. Additionally, the innovative nature of this study should be explicitly mentioned—specifically, its combination of these two concepts, typically studied independently, to provide novel insights into how they are interconnected. This distinction and integration should also be revisited in the discussion section. Existing literature suggests that the perception of distance is highly context-dependent. For example, would the effect still emerge when the perceived risk is low? Would it manifest if participants were asked to place items they do not own? Or, on the other hand, could the effect persist, as suggested by the lack of influence of the confederate manipulation on the results? Addressing these contextual factors could be done as suggestions for future studies, as answering them may lead to different theoretical and practical conclusions. Lenglart, L., Cartaud, A., Quesque, F., Sampaio, A., & Coello, Y. (2023 [Ref - 1]). Object coding in peripersonal space depends on object ownership. Quarterly Journal of Experimental Psychology, 76(8), 1925-1939. Givon-Benjio, N., Sokolover, H., Aderka, I. M., Hadad, B. S., & Okon-Singer, H. (2024 [Ref -2]). Perception of interpersonal distance and social distancing before and during COVID-19 pandemic. Scientific Reports, 14(1), 4568. 2. If the authors use the term "personal space" to refer specifically to peripersonal distance, they should explicitly adopt this terminology throughout the manuscript and to update the literature review, especially after the first paragraph. Alternatively, if "personal space" is intended to mean something different from the space surrounding the body, they should clearly define the term. 3. The discussion on interpersonal distance (IPD) during COVID-19 in the introduction is incomplete. While the authors cite studies demonstrating an enlargement of IPD following the pandemic, the paragraph overlooks important nuances. For instance, Iachini et al. (2021), which is already cited, found that the increase in IPD occurred only when subjective risk was high. Similarly, Givon-Benjio et al. (2024) compared data from before and after the outbreak and observed that subjective risk, rather than actual risk (e.g., infection rate), predicted changes in preferred interpersonal distance. Even when the actual risk was high, preferred interpersonal distance remained unchanged. These findings are further supported Cartaud et al., 2020). The introduction should reflect that the enlargement of IPD is not a universal or conclusive effect but is highly dependent on subjective risk levels. While the authors touch on subjective risk in the discussion, particularly when discussing perceived vulnerability to disease (PVD), this concept should receive greater emphasis both in the introduction and discussion to provide a more nuanced understanding of the findings. Cartaud, A., Quesque, F. & Coello, Y. Wearing a face mask against Covid-19 results in a reduction of social distancing. Plos One 15(12), e0243023 (2020 [Ref-3]). 4. Supporting the findings is a study that found that COVID-19 is linked to reduction in peripersonal distance, which can help explain why people want to put their belonging further away. Serino, S. et al. Sharpening of peripersonal space during the COVID-19 pandemic. Curr. Biol. 31(14), R889–R890 (2021 [Ref - 4]). 5. The fact that participants wore face masks should be mentioned earlier in the text, specifically in the Methods section, as it is a relevant procedural detail. Additionally, this should be discussed further in the Discussion section, with reference to studies examining the relationship between mask-wearing and interpersonal or peripersonal distance. Minor: 6.I found the observations about the role of smartphones and their potential impact on personal space particularly insightful in the discussion. 7. I suggest reconsidering the inclusion of Figure 3, as it primarily displays the results of a manipulation check, and may not add value to the main narrative of the paper. Is the work clearly and accurately presented and does it cite the current literature? Partly Is the study design appropriate and is the work technically sound? Yes Are sufficient details of methods and analysis provided to allow replication by others? Partly If applicable, is the statistical analysis and its interpretation appropriate? Yes Are all the source data underlying the results available to ensure full reproducibility? No source data required Are the conclusions drawn adequately supported by the results? Partly References 1. Lenglart L, Cartaud A, Quesque F, Sampaio A, et al.: Object coding in peripersonal space depends on object ownership. Q J Exp Psychol (Hove) . 2023; 76 (8): 1925-1939 PubMed Abstract | Publisher Full Text 2. Givon-Benjio N, Sokolover H, Aderka IM, Hadad BS, et al.: Perception of interpersonal distance and social distancing before and during COVID-19 pandemic. Sci Rep . 2024; 14 (1): 4568 PubMed Abstract | Publisher Full Text 3. Cartaud A, Quesque F, Coello Y: Wearing a face mask against Covid-19 results in a reduction of social distancing. PLoS One . 2020; 15 (12): e0243023 PubMed Abstract | Publisher Full Text 4. Serino S, Trabanelli S, Jandus C, Fellrath J, et al.: Sharpening of peripersonal space during the COVID-19 pandemic. Curr Biol . 2021; 31 (14): R889-R890 PubMed Abstract | Publisher Full Text Competing Interests: No competing interests were disclosed. Reviewer Expertise: Interpersonal distance (preference, perception) in COVID-19 as well as in clinical populations (social anxiety, autism). I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above. Close READ LESS CITE CITE HOW TO CITE THIS REPORT Givon-Benjio N. Reviewer Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.170298.r348889 ) The direct URL for this report is: https://f1000research.com/articles/12-199/v2#referee-response-348889 NOTE: it is important to ensure the information in square brackets after the title is included in all citations of this article. COPY CITATION DETAILS Report a concern Author Response 05 Feb 2025 Kaito Takashima , Graduate School of Human-Environment Studies, Kyushu University, Fukuoka, Japan 05 Feb 2025 Author Response The current study examined changes in the distance at which people placed their belongings before and after the COVID-19 outbreak in Japan. The authors employed an ecological task simulating a ... Continue reading The current study examined changes in the distance at which people placed their belongings before and after the COVID-19 outbreak in Japan. The authors employed an ecological task simulating a real-life scenario. The results suggest that the pandemic predicted an enlargement (or expansion) of the distance people placed their belongings from those of a confederate. This effect was not explained by whether the confederate was friendly or hostile, nor by a time*confederate interaction. Overall, I found the study very interesting and with the potential to make a meaningful contribution to existing knowledge. However, there are several areas that warrant further clarification and consideration: 1. A clear distinction should be made between interpersonal distance, which refers to the space between people (as discussed by Hall), and peripersonal distance, the space immediately surrounding the body within reach (as explored by Coello and Cartaud). This differentiation is critical for framing the study's context. The fear of infection during the COVID-19 pandemic is primarily linked to interpersonal distance. Studies have shown that fear of infection correlates with a preference for greater interpersonal distance and an underestimation of interpersonal space. However, these effects are tied to subjective perceptions of risk rather than objective risk of infection (Givon-Benjio et al., 2024). On the other hand, personal belongings conceptually align more with peripersonal distance. For example, Lenglart et al. (2023) demonstrated that personal items are perceived as more "within reach" compared to other objects, indicating an expansion of peripersonal distance representation. The paper by Coello and Cartaud (2021), cited in the introduction, suggests that interpersonal and peripersonal distances are interlinked and together influence social behavior. I recommend moving this discussion to the end of the paragraph, after clarifying the distinction between the two concepts. Additionally, the innovative nature of this study should be explicitly mentioned—specifically, its combination of these two concepts, typically studied independently, to provide novel insights into how they are interconnected. This distinction and integration should also be revisited in the discussion section. Existing literature suggests that the perception of distance is highly context-dependent. For example, would the effect still emerge when the perceived risk is low? Would it manifest if participants were asked to place items they do not own? Or, on the other hand, could the effect persist, as suggested by the lack of influence of the confederate manipulation on the results? Addressing these contextual factors could be done as suggestions for future studies, as answering them may lead to different theoretical and practical conclusions. Lenglart, L., Cartaud, A., Quesque, F., Sampaio, A., & Coello, Y. (2023 [Ref - 1]). Object coding in peripersonal space depends on object ownership. Quarterly Journal of Experimental Psychology, 76(8), 1925-1939. Givon-Benjio, N., Sokolover, H., Aderka, I. M., Hadad, B. S., & Okon-Singer, H. (2024 [Ref -2]). Perception of interpersonal distance and social distancing before and during COVID-19 pandemic. Scientific Reports, 14(1), 4568. Response: Thank you for acknowledging the innovative aspects of our study, and highlighting the importance of clearly distinguishing between interpersonal distance (IPD) and peripersonal distance (PPD). Following your suggestion, we have made the following revisions. Firstly, in the first paragraph of introduction, we clearly define and describe interpersonal space and peripersonal space. Then, at the end of the introduction, the innovation point of this paper is added, that is, it combines these two concepts for the first time and discusses their influence on social behavior. Finally,we expanded the discussion on future research direction by incorporating new questions based on your suggestions to highlight how contextual factors may influence our findings.These additions provide a stronger foundation for future studies investigating how interpersonal and peripersonal space interact under different conditions. We sincerely appreciate your constructive feedback, as it has significantly enhanced the theoretical clarity and coherence of our manuscript. Revised version: use underline__ …Social psychology and proxemics have long addressed personal space as the spatial range surrounding the individual (Sommer, 1959; Hall, 1966). The space around the individual may exist in two forms. One is interpersonal distance, the area around the body that individuals maintain between themselves and others during social interactions (Candini et al., 2021). The other one is peripersonal space, which is an adaptive and flexible interface between the body and the environment The space around them represents a mediation zone between the body and the environment, contributing to the organization of social life. For example, when this space is encroached by others, we may feel uncomfortable or may prepare our bodies for defensive responses (Hall, 1966; Coello and Cartaud, 2021). ……… …How has the COVID-19 pandemic and countermeasures against it changed human-human and human-object interactions? Considering the findings of Ariga (2016), one’s personal space extends to his/her belongings, leaving them with an ‘extended personal space’. The present study aimed to examine if the ‘extended personal space’ increased as well as the personal space that has been affected under the pandemic of COVID-19. The fear of infection during the COVID-19 pandemic is closely associated with interpersonal distance. Research indicates that this fear is linked to a tendency to prefer greater interpersonal distance and to underestimate interpersonal space. However, these tendencies stem from subjective perceptions of risk rather than an actual objective risk of infection (Givon-Benjio et al., 2024). On the other hand, personal belongings are more closely related to peripersonal distance. For instance, Lenglart et al. (2023) found that individuals perceive personal items as being more "within reach" compared to other objects, suggesting an expansion in the representation of peripersonal distance. Based on the Coello and Cartaud, they indicated that interpersonal and peripersonal distances are interlinked and together influence social behavior. Therefore, in this study, we innovatively combine these two concepts for the first time to explore the impact of the combination of these two forms of personal space on social actions. Discussion: To dissociate the factor of the pandemic from other potential factors, conducting the study using the same procedure again after the pandemic would be effective. Additionally, future studies should further examine how interpersonal and peripersonal distances interact in different contexts. For example, the level of perceived infectability (i.e., beliefs about one’s own susceptibility to infectious diseases) in 2023 has dropped to the same level as before the COVID-19 pandemic in Japan (Ikeda et al., 2024). Although the number of diagnosed COVID-19 cases remains high, people's subjective risk perception has declined. The potential changes in sensitivity suggested by such reports provide us with numerous possibilities for discussion. Would the effect still emerge when the perceived risk of infection is low? Additionally, would it manifest if participants were asked to place items they do not own? Alternatively, the persistence of the effect—despite the lack of influence of the confederate’s friendliness—suggests that the expansion of peripersonal space during the pandemic might be independent of social cues. Furthermore, the perception of distance may be shaped by long-term societal and technological changes. The widespread use of smartphones and social media in the 2010s might have altered norms around physical proximity and social interaction. Future research could investigate whether personal space norms adapt to such technological shifts and how these changes interact with interpersonal and peripersonal distances. Added references: Candini, M., Battaglia, S., Benassi, M., di Pellegrino, G., & Frassinetti, F. (2021). The physiological correlates of interpersonal space. Scientific Reports , 11 (1), 2611. https://doi.org/10.1038/s41598-021-82223-2 Lenglart, L., Cartaud, A., Quesque, F., Sampaio, A., & Coello, Y. (2023). Object coding in peripersonal space depends on object ownership. Quarterly Journal of Experimental Psychology , 76 (8), 1925-1939. https://doi.org/10.1177/17470218221128306 Givon-Benjio, N., Sokolover, H., Aderka, I. M., Hadad, B. S., & Okon-Singer, H. (2024). Perception of interpersonal distance and social distancing before and during COVID-19 pandemic. Scientific Reports , 14 (1), 4568. https://doi.org/10.1038/s41598-024-55218-y Ikeda A, Sasaki K, Yamada Y.: Evolution of perceived vulnerability to infection in Japan during the COVID-19 pandemic. Qeios. 2024. https://doi.org/10.32388/4CO88Y.4 2. If the authors use the term "personal space" to refer specifically to peripersonal distance, they should explicitly adopt this terminology throughout the manuscript and to update the literature review, especially after the first paragraph. Alternatively, if "personal space" is intended to mean something different from the space surrounding the body, they should clearly define the term. Response： Thank you for confirming the uniformity of terms. In the present study, "personal space" refers to the surrounding space centered on one's body that is not invaded by others in social activities. Closer to the concept of peripersonal space. In addition, the personal space extended by personal belongings is also closer to the "peripersonal space". We clarified the definition of peripersonal space in the first paragraph of introduction and the reference to personal space in our manuscript to ensure the clear and consistent use of terms. Revised version: Social psychology and proxemics have long addressed personal space as the spatial range surrounding the individual ( Sommer, 1959; Hall, 1966). The space around the individual may exist in two forms. One is interpersonal distance, the area around the body that individuals maintain between themselves and others during social interactions (Candini et al., 2021). The other one is peripersonal space, which is an adaptive and flexible interface between the body and the environment, contributing to the organization of social life. For example, when this space is encroached by others, we may feel uncomfortable or may prepare our bodies for defensive responses ( Hall, 1966; Coello and Cartaud, 2021) . In our study, the concept of 'personal space,' as referenced later, aligns more closely with the notion of peripersonal space. This refers to the space immediately surrounding the body, within reach, centered on the individual, and typically protected from intrusion during social interactions. One observed phenomenon is in some school situations where there are desk-mates; after an argument, desk-mates will avoid putting their stationery close to the other’s belongings. It is possible that people develop a tendency to recognize personal belonging as a representation of the self at an early age ( Pedersen, 1973). According to James (1890), the self is the sum of all that he can call his, including all possessions, which gives him the same emotions. Briefly, we regard our possessions as part of ourselves. This intrinsic association between personal belongings and the self-forms the foundation for understanding how external objects, including tools and technologies, can become integrated into one’s sense of self, extending the boundaries of personal space. Studies on body ownership illusions suggest that the integration of external objects or virtual representations into one’s sense of self occurs through multisensory signals, highlighting the neural mechanisms underlying extended personal space (Nilsson & Kalckert, 2021). Is this sense of ownership of objects related to personal space? Ariga (2016) reported that participants placed their own objects at a greater distance from the objects of those who were unfavorable. These findings suggest that individuals’ personal space extended to the space surrounding their belongings (i.e., extended personal space). The placement of such personal belongings can be considered the most significant evidence of an extension of personal space, as it shares the same characteristics with personal space ( Russell & Ward, 1982; Becker, 1973), that the variability depending on the level of familiarity with others. Moreover, recent studies have shown that object ownership influences the representation of peripersonal space. Specifically, self-owned objects within the peripersonal space are processed faster and perceived as more reachable compared to objects owned by others, suggesting an extension of peripersonal space representation around self belongings (Lenglart et al., 2023). This effect is particularly pronounced in individuals with higher interpersonal sensitivity, as their peripersonal space boundaries dynamically adapt in response to social contexts. Further supporting this perspective, Rabellino et al. (2020) highlight that peripersonal space is not only critical for physical interactions with the environment but also closely tied to bodily self-consciousness. They suggest that peripersonal space representation involves multisensory processing and serves both protective and social functions, allowing individuals to dynamically adjust to interactions with others. These findings further support the idea that ownership can extend personal space to include the area surrounding one's possessions, reinforcing the concept of "extended personal space." Added references Lenglart, L., Cartaud, A., Quesque, F., Sampaio, A., & Coello, Y. (2023). Object coding in peripersonal space depends on object ownership. Quarterly Journal of Experimental Psychology , 76 (8), 1925-1939. https://doi.org/10.1177/17470218221128306 Nilsson, M., & Kalckert, A. (2021). Region‐of‐interest analysis approaches in neuroimaging studies of body ownership: An activation likelihood estimation meta‐analysis. European Journal of Neuroscience , 54 (11), 7974-7988. https://doi.org/10.1111/ejn.15534 Rabellino, D., Frewen, P. A., McKinnon, M. C., & Lanius, R. A. (2020). Peripersonal space and bodily self-consciousness: implications for psychological trauma-related disorders. Frontiers in Neuroscience , 14 , 586605. https://doi.org/10.3389/fnins.2020.586605 3. The discussion on interpersonal distance (IPD) during COVID-19 in the introduction is incomplete. While the authors cite studies demonstrating an enlargement of IPD following the pandemic, the paragraph overlooks important nuances. For instance, Iachini et al. (2021), which is already cited, found that the increase in IPD occurred only when subjective risk was high. Similarly, Givon-Benjio et al. (2024) compared data from before and after the outbreak and observed that subjective risk, rather than actual risk (e.g., infection rate), predicted changes in preferred interpersonal distance. Even when the actual risk was high, preferred interpersonal distance remained unchanged. These findings are further supported Cartaud et al., 2020). The introduction should reflect that the enlargement of IPD is not a universal or conclusive effect but is highly dependent on subjective risk levels. While the authors touch on subjective risk in the discussion, particularly when discussing perceived vulnerability to disease (PVD), this concept should receive greater emphasis both in the introduction and discussion to provide a more nuanced understanding of the findings. Cartaud, A., Quesque, F. & Coello, Y. Wearing a face mask against Covid-19 results in a reduction of social distancing. Plos One 15(12), e0243023 (2020 [Ref-3]). Response: We appreciate your insightful comments on the nuanced relationship between interpersonal distance and subjective risk during the COVID-19 pandemic. In response, we have revised the introduction to provide a more balanced discussion on the enlargement of interpersonal distance, emphasizing that this phenomenon is highly dependent on subjective risk levels rather than being a universal or conclusive effect. Specifically, we have incorporated findings from Iachini et al. (2021), Givon-Benjio et al. (2024), and Cartaud et al. (2020) to illustrate how subjective risk plays a crucial role in modulating interpersonal distance. Furthermore, we have strengthened the connection between subjective risk and the concept of extended personal space in the discussion part, which forms the core focus of our study. For details revise, please see "Revised version" Revised version: …Recent studies have reported that interpersonal distance (IPD) increased during the COVID-19 pandemic ( Holt et al. , 2022; Iachini et al. , 2021), and enlarged IPD preferences were predicted to persist beyond the pandemic ( Welsch et al., 2021). However, it is important to note that the enlargement of IPD is not a universal phenomenon. As Iachini et al. (2021) observed, IPD increases only when subjective risk levels are high. Similarly, Givon-Benjio et al. (2024) demonstrated that subjective risk, rather than actual infection risk, predicted changes in preferred IPD. Cartaud et al. (2020) further supported this by showing that even under conditions of high actual risk, individuals’ preferred IPD remained unchanged unless subjective risk was elevated. The results of an experiment in Arabia revealed that in the post-epidemic era, 76% of the participants were already subjectively reluctant to share close physical distance or socially polite touch with others ( Khan et al., 2021). Responding to precautions, the external manifestation is that we have actively increased our physical distance, but in reality, personal space has also expanded accordingly. In several studies related to personal distance in COVID-19, Fini et al. (2021)showed that interpersonal distance is influenced by the perception of realistic threat measured through the COVID-19 threat. In addition, previous research proposed that not only the perception of infection will make the public practice social distancing, but the behavior of practicing social distancing is related to specific individuals as well as related to the social meaning of collective health ( Fazio et al ., 2021). Discussion : Since personal belongings also can be the source of infection through aerosols, the perceived risk of infection may extend to them. It is precisely due to the increased subjective perception of risk that, in the context of COVID-19, the extension of personal belongings comes to represent the characteristics of personal space, and the distance between personal belongings also increases. Participants without sufficient prior information could place their belongings at a distance from the confederate’s belongings to avoid contamination as they were unsure whether the stranger and their belongings were infected with viruses. 4. Supporting the findings is a study that found that COVID-19 is linked to reduction in peripersonal distance, which can help explain why people want to put their belonging further away. Serino, S. et al. Sharpening of peripersonal space during the COVID-19 pandemic. Curr. Biol. 31(14), R889–R890 (2021 [Ref - 4]). Response: Thank you for pointing out this relevant study by Serino et al. (2021). We agree that their findings on the sharpening of peripersonal space during the COVID-19 pandemic provide valuable support for our study. We have incorporated this reference into the discussion section to further explain the increased distance observed between personal belongings. Specifically, we added the following paragraph as in the "Revised version". Revised Version: Several studies have confirmed the increase in personal space during the COVID-19 pandemic and suggested the practice of social distancing attributed to the increase (Fini, Tummolini, and Borghi, 2021; Fazio et al., 2021). Moreover, our study found that the distance between objects increased during the pandemic. Recent findings from studies on the psychological impact of the COVID-19 pandemic provide additional support for our findings. For example, Serino et al. (2021) demonstrated that the pandemic led to a sharpening of peripersonal space boundaries, with individuals adapting their spatial perceptions in response to increased health-related concerns. This phenomenon aligns with our observation that the distance between personal belongings increased during the pandemic. The findings suggest that participants might have subconsciously extended their spatial boundaries to maintain greater safety and reduce perceived risks associated with potential contamination. This adaptation, as highlighted by Serino et al. (2021), may explain why people positioned their belongings farther away from other's during the pandemic. Considering Ariga (2016), personal belongings have the same personal space-like properties as the owner, belongings also maintain their social distance when they are placed. This distance could manifest in the elongated distance of personal belongings. 5. The fact that participants wore face masks should be mentioned earlier in the text, specifically in the Methods section, as it is a relevant procedural detail. Additionally, this should be discussed further in the Discussion section, with reference to studies examining the relationship between mask-wearing and interpersonal or peripersonal distance. Response: We revised the Methods section to include this procedural detail. Additionally, we expanded the Discussion section to explore the potential influence of mask-wearing on interpersonal and peripersonal distance, supported by Cartaud et al.(2020). Revised version: Methods The inclusion criteria were native Japanese or international students who could speak Japanese proficiently. They were paid 1000 yen to agree to participate. All participants were required to wear face masks throughout the experiment as part of standard COVID-19 precautions. Discussion In fact, all valid participants in this study voluntarily wore face masks, which is a routine infection control measure. Beyond compliance, mask-wearing might have also influenced the observed spatial distancing behavior. Research has shown that wearing face masks can alter interpersonal perceptions and decrease interpersonal and peripersonal distances in certain contexts. For example, Cartaud et al. (2020) found that individuals perceived as wearing face masks are considered more trustworthy, leading to reduced physical distance. Similarly, Biggio et al. (2022) reported that mask-wearing shapes interpersonal space by fostering a sense of safety and reducing the need for extended spatial boundaries. In our study, while participants wore face masks during the experiment, the observed increase in distance between personal belongings suggests that compliance with infection control measures and risk-avoidance behaviors might interact differently when participants place objects instead of interacting directly with people. Minor: 6.I found the observations about the role of smartphones and their potential impact on personal space particularly insightful in the discussion. Response: Thank you for your feedback. Our manuscript mentions that smartphones and social media may affect interpersonal distance, but not in conjunction with the concept of interpersonal/intimate distance. To that end, we modified and expanded the section (the modifications here partly same as the response to the question 1, but we're still showing it to you here) : Revised Version: Furthermore, the perception of distance may be shaped by long-term societal and technological changes. The widespread use of smartphones and social media in the 2010s might have altered norms around physical proximity and social interaction. Future research could investigate whether personal space norms adapt to such technological shifts and how these changes interact with interpersonal and peripersonal distances. 7. I suggest reconsidering the inclusion of Figure 3, as it primarily displays the results of a manipulation check, and may not add value to the main narrative of the paper. Reponse: Thank you for your comments. Figure 3 includes part of the results described in the text but also provides a visualization of the data distribution for the manipulation check. To streamline the manuscript, we removed Figure 3 while retaining the textual description, as we believe that the results of the manipulation check are crucial for demonstrating the validity of our experiment design. Revised version: …we calculated the mean favorability for each condition (friendly and unfriendly). The current study examined changes in the distance at which people placed their belongings before and after the COVID-19 outbreak in Japan. The authors employed an ecological task simulating a real-life scenario. The results suggest that the pandemic predicted an enlargement (or expansion) of the distance people placed their belongings from those of a confederate. This effect was not explained by whether the confederate was friendly or hostile, nor by a time*confederate interaction. Overall, I found the study very interesting and with the potential to make a meaningful contribution to existing knowledge. However, there are several areas that warrant further clarification and consideration: 1. A clear distinction should be made between interpersonal distance, which refers to the space between people (as discussed by Hall), and peripersonal distance, the space immediately surrounding the body within reach (as explored by Coello and Cartaud). This differentiation is critical for framing the study's context. The fear of infection during the COVID-19 pandemic is primarily linked to interpersonal distance. Studies have shown that fear of infection correlates with a preference for greater interpersonal distance and an underestimation of interpersonal space. However, these effects are tied to subjective perceptions of risk rather than objective risk of infection (Givon-Benjio et al., 2024). On the other hand, personal belongings conceptually align more with peripersonal distance. For example, Lenglart et al. (2023) demonstrated that personal items are perceived as more "within reach" compared to other objects, indicating an expansion of peripersonal distance representation. The paper by Coello and Cartaud (2021), cited in the introduction, suggests that interpersonal and peripersonal distances are interlinked and together influence social behavior. I recommend moving this discussion to the end of the paragraph, after clarifying the distinction between the two concepts. Additionally, the innovative nature of this study should be explicitly mentioned—specifically, its combination of these two concepts, typically studied independently, to provide novel insights into how they are interconnected. This distinction and integration should also be revisited in the discussion section. Existing literature suggests that the perception of distance is highly context-dependent. For example, would the effect still emerge when the perceived risk is low? Would it manifest if participants were asked to place items they do not own? Or, on the other hand, could the effect persist, as suggested by the lack of influence of the confederate manipulation on the results? Addressing these contextual factors could be done as suggestions for future studies, as answering them may lead to different theoretical and practical conclusions. Lenglart, L., Cartaud, A., Quesque, F., Sampaio, A., & Coello, Y. (2023 [Ref - 1]). Object coding in peripersonal space depends on object ownership. Quarterly Journal of Experimental Psychology, 76(8), 1925-1939. Givon-Benjio, N., Sokolover, H., Aderka, I. M., Hadad, B. S., & Okon-Singer, H. (2024 [Ref -2]). Perception of interpersonal distance and social distancing before and during COVID-19 pandemic. Scientific Reports, 14(1), 4568. Response: Thank you for acknowledging the innovative aspects of our study, and highlighting the importance of clearly distinguishing between interpersonal distance (IPD) and peripersonal distance (PPD). Following your suggestion, we have made the following revisions. Firstly, in the first paragraph of introduction, we clearly define and describe interpersonal space and peripersonal space. Then, at the end of the introduction, the innovation point of this paper is added, that is, it combines these two concepts for the first time and discusses their influence on social behavior. Finally,we expanded the discussion on future research direction by incorporating new questions based on your suggestions to highlight how contextual factors may influence our findings.These additions provide a stronger foundation for future studies investigating how interpersonal and peripersonal space interact under different conditions. We sincerely appreciate your constructive feedback, as it has significantly enhanced the theoretical clarity and coherence of our manuscript. Revised version: use underline__ …Social psychology and proxemics have long addressed personal space as the spatial range surrounding the individual (Sommer, 1959; Hall, 1966). The space around the individual may exist in two forms. One is interpersonal distance, the area around the body that individuals maintain between themselves and others during social interactions (Candini et al., 2021). The other one is peripersonal space, which is an adaptive and flexible interface between the body and the environment The space around them represents a mediation zone between the body and the environment, contributing to the organization of social life. For example, when this space is encroached by others, we may feel uncomfortable or may prepare our bodies for defensive responses (Hall, 1966; Coello and Cartaud, 2021). ……… …How has the COVID-19 pandemic and countermeasures against it changed human-human and human-object interactions? Considering the findings of Ariga (2016), one’s personal space extends to his/her belongings, leaving them with an ‘extended personal space’. The present study aimed to examine if the ‘extended personal space’ increased as well as the personal space that has been affected under the pandemic of COVID-19. The fear of infection during the COVID-19 pandemic is closely associated with interpersonal distance. Research indicates that this fear is linked to a tendency to prefer greater interpersonal distance and to underestimate interpersonal space. However, these tendencies stem from subjective perceptions of risk rather than an actual objective risk of infection (Givon-Benjio et al., 2024). On the other hand, personal belongings are more closely related to peripersonal distance. For instance, Lenglart et al. (2023) found that individuals perceive personal items as being more "within reach" compared to other objects, suggesting an expansion in the representation of peripersonal distance. Based on the Coello and Cartaud, they indicated that interpersonal and peripersonal distances are interlinked and together influence social behavior. Therefore, in this study, we innovatively combine these two concepts for the first time to explore the impact of the combination of these two forms of personal space on social actions. Discussion: To dissociate the factor of the pandemic from other potential factors, conducting the study using the same procedure again after the pandemic would be effective. Additionally, future studies should further examine how interpersonal and peripersonal distances interact in different contexts. For example, the level of perceived infectability (i.e., beliefs about one’s own susceptibility to infectious diseases) in 2023 has dropped to the same level as before the COVID-19 pandemic in Japan (Ikeda et al., 2024). Although the number of diagnosed COVID-19 cases remains high, people's subjective risk perception has declined. The potential changes in sensitivity suggested by such reports provide us with numerous possibilities for discussion. Would the effect still emerge when the perceived risk of infection is low? Additionally, would it manifest if participants were asked to place items they do not own? Alternatively, the persistence of the effect—despite the lack of influence of the confederate’s friendliness—suggests that the expansion of peripersonal space during the pandemic might be independent of social cues. Furthermore, the perception of distance may be shaped by long-term societal and technological changes. The widespread use of smartphones and social media in the 2010s might have altered norms around physical proximity and social interaction. Future research could investigate whether personal space norms adapt to such technological shifts and how these changes interact with interpersonal and peripersonal distances. Added references: Candini, M., Battaglia, S., Benassi, M., di Pellegrino, G., & Frassinetti, F. (2021). The physiological correlates of interpersonal space. Scientific Reports , 11 (1), 2611. https://doi.org/10.1038/s41598-021-82223-2 Lenglart, L., Cartaud, A., Quesque, F., Sampaio, A., & Coello, Y. (2023). Object coding in peripersonal space depends on object ownership. Quarterly Journal of Experimental Psychology , 76 (8), 1925-1939. https://doi.org/10.1177/17470218221128306 Givon-Benjio, N., Sokolover, H., Aderka, I. M., Hadad, B. S., & Okon-Singer, H. (2024). Perception of interpersonal distance and social distancing before and during COVID-19 pandemic. Scientific Reports , 14 (1), 4568. https://doi.org/10.1038/s41598-024-55218-y Ikeda A, Sasaki K, Yamada Y.: Evolution of perceived vulnerability to infection in Japan during the COVID-19 pandemic. Qeios. 2024. https://doi.org/10.32388/4CO88Y.4 2. If the authors use the term "personal space" to refer specifically to peripersonal distance, they should explicitly adopt this terminology throughout the manuscript and to update the literature review, especially after the first paragraph. Alternatively, if "personal space" is intended to mean something different from the space surrounding the body, they should clearly define the term. Response： Thank you for confirming the uniformity of terms. In the present study, "personal space" refers to the surrounding space centered on one's body that is not invaded by others in social activities. Closer to the concept of peripersonal space. In addition, the personal space extended by personal belongings is also closer to the "peripersonal space". We clarified the definition of peripersonal space in the first paragraph of introduction and the reference to personal space in our manuscript to ensure the clear and consistent use of terms. Revised version: Social psychology and proxemics have long addressed personal space as the spatial range surrounding the individual ( Sommer, 1959; Hall, 1966). The space around the individual may exist in two forms. One is interpersonal distance, the area around the body that individuals maintain between themselves and others during social interactions (Candini et al., 2021). The other one is peripersonal space, which is an adaptive and flexible interface between the body and the environment, contributing to the organization of social life. For example, when this space is encroached by others, we may feel uncomfortable or may prepare our bodies for defensive responses ( Hall, 1966; Coello and Cartaud, 2021) . In our study, the concept of 'personal space,' as referenced later, aligns more closely with the notion of peripersonal space. This refers to the space immediately surrounding the body, within reach, centered on the individual, and typically protected from intrusion during social interactions. One observed phenomenon is in some school situations where there are desk-mates; after an argument, desk-mates will avoid putting their stationery close to the other’s belongings. It is possible that people develop a tendency to recognize personal belonging as a representation of the self at an early age ( Pedersen, 1973). According to James (1890), the self is the sum of all that he can call his, including all possessions, which gives him the same emotions. Briefly, we regard our possessions as part of ourselves. This intrinsic association between personal belongings and the self-forms the foundation for understanding how external objects, including tools and technologies, can become integrated into one’s sense of self, extending the boundaries of personal space. Studies on body ownership illusions suggest that the integration of external objects or virtual representations into one’s sense of self occurs through multisensory signals, highlighting the neural mechanisms underlying extended personal space (Nilsson & Kalckert, 2021). Is this sense of ownership of objects related to personal space? Ariga (2016) reported that participants placed their own objects at a greater distance from the objects of those who were unfavorable. These findings suggest that individuals’ personal space extended to the space surrounding their belongings (i.e., extended personal space). The placement of such personal belongings can be considered the most significant evidence of an extension of personal space, as it shares the same characteristics with personal space ( Russell & Ward, 1982; Becker, 1973), that the variability depending on the level of familiarity with others. Moreover, recent studies have shown that object ownership influences the representation of peripersonal space. Specifically, self-owned objects within the peripersonal space are processed faster and perceived as more reachable compared to objects owned by others, suggesting an extension of peripersonal space representation around self belongings (Lenglart et al., 2023). This effect is particularly pronounced in individuals with higher interpersonal sensitivity, as their peripersonal space boundaries dynamically adapt in response to social contexts. Further supporting this perspective, Rabellino et al. (2020) highlight that peripersonal space is not only critical for physical interactions with the environment but also closely tied to bodily self-consciousness. They suggest that peripersonal space representation involves multisensory processing and serves both protective and social functions, allowing individuals to dynamically adjust to interactions with others. These findings further support the idea that ownership can extend personal space to include the area surrounding one's possessions, reinforcing the concept of "extended personal space." Added references Lenglart, L., Cartaud, A., Quesque, F., Sampaio, A., & Coello, Y. (2023). Object coding in peripersonal space depends on object ownership. Quarterly Journal of Experimental Psychology , 76 (8), 1925-1939. https://doi.org/10.1177/17470218221128306 Nilsson, M., & Kalckert, A. (2021). Region‐of‐interest analysis approaches in neuroimaging studies of body ownership: An activation likelihood estimation meta‐analysis. European Journal of Neuroscience , 54 (11), 7974-7988. https://doi.org/10.1111/ejn.15534 Rabellino, D., Frewen, P. A., McKinnon, M. C., & Lanius, R. A. (2020). Peripersonal space and bodily self-consciousness: implications for psychological trauma-related disorders. Frontiers in Neuroscience , 14 , 586605. https://doi.org/10.3389/fnins.2020.586605 3. The discussion on interpersonal distance (IPD) during COVID-19 in the introduction is incomplete. While the authors cite studies demonstrating an enlargement of IPD following the pandemic, the paragraph overlooks important nuances. For instance, Iachini et al. (2021), which is already cited, found that the increase in IPD occurred only when subjective risk was high. Similarly, Givon-Benjio et al. (2024) compared data from before and after the outbreak and observed that subjective risk, rather than actual risk (e.g., infection rate), predicted changes in preferred interpersonal distance. Even when the actual risk was high, preferred interpersonal distance remained unchanged. These findings are further supported Cartaud et al., 2020). The introduction should reflect that the enlargement of IPD is not a universal or conclusive effect but is highly dependent on subjective risk levels. While the authors touch on subjective risk in the discussion, particularly when discussing perceived vulnerability to disease (PVD), this concept should receive greater emphasis both in the introduction and discussion to provide a more nuanced understanding of the findings. Cartaud, A., Quesque, F. & Coello, Y. Wearing a face mask against Covid-19 results in a reduction of social distancing. Plos One 15(12), e0243023 (2020 [Ref-3]). Response: We appreciate your insightful comments on the nuanced relationship between interpersonal distance and subjective risk during the COVID-19 pandemic. In response, we have revised the introduction to provide a more balanced discussion on the enlargement of interpersonal distance, emphasizing that this phenomenon is highly dependent on subjective risk levels rather than being a universal or conclusive effect. Specifically, we have incorporated findings from Iachini et al. (2021), Givon-Benjio et al. (2024), and Cartaud et al. (2020) to illustrate how subjective risk plays a crucial role in modulating interpersonal distance. Furthermore, we have strengthened the connection between subjective risk and the concept of extended personal space in the discussion part, which forms the core focus of our study. For details revise, please see "Revised version" Revised version: …Recent studies have reported that interpersonal distance (IPD) increased during the COVID-19 pandemic ( Holt et al. , 2022; Iachini et al. , 2021), and enlarged IPD preferences were predicted to persist beyond the pandemic ( Welsch et al., 2021). However, it is important to note that the enlargement of IPD is not a universal phenomenon. As Iachini et al. (2021) observed, IPD increases only when subjective risk levels are high. Similarly, Givon-Benjio et al. (2024) demonstrated that subjective risk, rather than actual infection risk, predicted changes in preferred IPD. Cartaud et al. (2020) further supported this by showing that even under conditions of high actual risk, individuals’ preferred IPD remained unchanged unless subjective risk was elevated. The results of an experiment in Arabia revealed that in the post-epidemic era, 76% of the participants were already subjectively reluctant to share close physical distance or socially polite touch with others ( Khan et al., 2021). Responding to precautions, the external manifestation is that we have actively increased our physical distance, but in reality, personal space has also expanded accordingly. In several studies related to personal distance in COVID-19, Fini et al. (2021)showed that interpersonal distance is influenced by the perception of realistic threat measured through the COVID-19 threat. In addition, previous research proposed that not only the perception of infection will make the public practice social distancing, but the behavior of practicing social distancing is related to specific individuals as well as related to the social meaning of collective health ( Fazio et al ., 2021). Discussion : Since personal belongings also can be the source of infection through aerosols, the perceived risk of infection may extend to them. It is precisely due to the increased subjective perception of risk that, in the context of COVID-19, the extension of personal belongings comes to represent the characteristics of personal space, and the distance between personal belongings also increases. Participants without sufficient prior information could place their belongings at a distance from the confederate’s belongings to avoid contamination as they were unsure whether the stranger and their belongings were infected with viruses. 4. Supporting the findings is a study that found that COVID-19 is linked to reduction in peripersonal distance, which can help explain why people want to put their belonging further away. Serino, S. et al. Sharpening of peripersonal space during the COVID-19 pandemic. Curr. Biol. 31(14), R889–R890 (2021 [Ref - 4]). Response: Thank you for pointing out this relevant study by Serino et al. (2021). We agree that their findings on the sharpening of peripersonal space during the COVID-19 pandemic provide valuable support for our study. We have incorporated this reference into the discussion section to further explain the increased distance observed between personal belongings. Specifically, we added the following paragraph as in the "Revised version". Revised Version: Several studies have confirmed the increase in personal space during the COVID-19 pandemic and suggested the practice of social distancing attributed to the increase (Fini, Tummolini, and Borghi, 2021; Fazio et al., 2021). Moreover, our study found that the distance between objects increased during the pandemic. Recent findings from studies on the psychological impact of the COVID-19 pandemic provide additional support for our findings. For example, Serino et al. (2021) demonstrated that the pandemic led to a sharpening of peripersonal space boundaries, with individuals adapting their spatial perceptions in response to increased health-related concerns. This phenomenon aligns with our observation that the distance between personal belongings increased during the pandemic. The findings suggest that participants might have subconsciously extended their spatial boundaries to maintain greater safety and reduce perceived risks associated with potential contamination. This adaptation, as highlighted by Serino et al. (2021), may explain why people positioned their belongings farther away from other's during the pandemic. Considering Ariga (2016), personal belongings have the same personal space-like properties as the owner, belongings also maintain their social distance when they are placed. This distance could manifest in the elongated distance of personal belongings. 5. The fact that participants wore face masks should be mentioned earlier in the text, specifically in the Methods section, as it is a relevant procedural detail. Additionally, this should be discussed further in the Discussion section, with reference to studies examining the relationship between mask-wearing and interpersonal or peripersonal distance. Response: We revised the Methods section to include this procedural detail. Additionally, we expanded the Discussion section to explore the potential influence of mask-wearing on interpersonal and peripersonal distance, supported by Cartaud et al.(2020). Revised version: Methods The inclusion criteria were native Japanese or international students who could speak Japanese proficiently. They were paid 1000 yen to agree to participate. All participants were required to wear face masks throughout the experiment as part of standard COVID-19 precautions. Discussion In fact, all valid participants in this study voluntarily wore face masks, which is a routine infection control measure. Beyond compliance, mask-wearing might have also influenced the observed spatial distancing behavior. Research has shown that wearing face masks can alter interpersonal perceptions and decrease interpersonal and peripersonal distances in certain contexts. For example, Cartaud et al. (2020) found that individuals perceived as wearing face masks are considered more trustworthy, leading to reduced physical distance. Similarly, Biggio et al. (2022) reported that mask-wearing shapes interpersonal space by fostering a sense of safety and reducing the need for extended spatial boundaries. In our study, while participants wore face masks during the experiment, the observed increase in distance between personal belongings suggests that compliance with infection control measures and risk-avoidance behaviors might interact differently when participants place objects instead of interacting directly with people. Minor: 6.I found the observations about the role of smartphones and their potential impact on personal space particularly insightful in the discussion. Response: Thank you for your feedback. Our manuscript mentions that smartphones and social media may affect interpersonal distance, but not in conjunction with the concept of interpersonal/intimate distance. To that end, we modified and expanded the section (the modifications here partly same as the response to the question 1, but we're still showing it to you here) : Revised Version: Furthermore, the perception of distance may be shaped by long-term societal and technological changes. The widespread use of smartphones and social media in the 2010s might have altered norms around physical proximity and social interaction. Future research could investigate whether personal space norms adapt to such technological shifts and how these changes interact with interpersonal and peripersonal distances. 7. I suggest reconsidering the inclusion of Figure 3, as it primarily displays the results of a manipulation check, and may not add value to the main narrative of the paper. Reponse: Thank you for your comments. Figure 3 includes part of the results described in the text but also provides a visualization of the data distribution for the manipulation check. To streamline the manuscript, we removed Figure 3 while retaining the textual description, as we believe that the results of the manipulation check are crucial for demonstrating the validity of our experiment design. Revised version: …we calculated the mean favorability for each condition (friendly and unfriendly). Competing Interests: No competing interests were disclosed. Close Report a concern Respond or Comment COMMENTS ON THIS REPORT Author Response 05 Feb 2025 Kaito Takashima , Graduate School of Human-Environment Studies, Kyushu University, Fukuoka, Japan 05 Feb 2025 Author Response The current study examined changes in the distance at which people placed their belongings before and after the COVID-19 outbreak in Japan. The authors employed an ecological task simulating a ... Continue reading The current study examined changes in the distance at which people placed their belongings before and after the COVID-19 outbreak in Japan. The authors employed an ecological task simulating a real-life scenario. The results suggest that the pandemic predicted an enlargement (or expansion) of the distance people placed their belongings from those of a confederate. This effect was not explained by whether the confederate was friendly or hostile, nor by a time*confederate interaction. Overall, I found the study very interesting and with the potential to make a meaningful contribution to existing knowledge. However, there are several areas that warrant further clarification and consideration: 1. A clear distinction should be made between interpersonal distance, which refers to the space between people (as discussed by Hall), and peripersonal distance, the space immediately surrounding the body within reach (as explored by Coello and Cartaud). This differentiation is critical for framing the study's context. The fear of infection during the COVID-19 pandemic is primarily linked to interpersonal distance. Studies have shown that fear of infection correlates with a preference for greater interpersonal distance and an underestimation of interpersonal space. However, these effects are tied to subjective perceptions of risk rather than objective risk of infection (Givon-Benjio et al., 2024). On the other hand, personal belongings conceptually align more with peripersonal distance. For example, Lenglart et al. (2023) demonstrated that personal items are perceived as more "within reach" compared to other objects, indicating an expansion of peripersonal distance representation. The paper by Coello and Cartaud (2021), cited in the introduction, suggests that interpersonal and peripersonal distances are interlinked and together influence social behavior. I recommend moving this discussion to the end of the paragraph, after clarifying the distinction between the two concepts. Additionally, the innovative nature of this study should be explicitly mentioned—specifically, its combination of these two concepts, typically studied independently, to provide novel insights into how they are interconnected. This distinction and integration should also be revisited in the discussion section. Existing literature suggests that the perception of distance is highly context-dependent. For example, would the effect still emerge when the perceived risk is low? Would it manifest if participants were asked to place items they do not own? Or, on the other hand, could the effect persist, as suggested by the lack of influence of the confederate manipulation on the results? Addressing these contextual factors could be done as suggestions for future studies, as answering them may lead to different theoretical and practical conclusions. Lenglart, L., Cartaud, A., Quesque, F., Sampaio, A., & Coello, Y. (2023 [Ref - 1]). Object coding in peripersonal space depends on object ownership. Quarterly Journal of Experimental Psychology, 76(8), 1925-1939. Givon-Benjio, N., Sokolover, H., Aderka, I. M., Hadad, B. S., & Okon-Singer, H. (2024 [Ref -2]). Perception of interpersonal distance and social distancing before and during COVID-19 pandemic. Scientific Reports, 14(1), 4568. Response: Thank you for acknowledging the innovative aspects of our study, and highlighting the importance of clearly distinguishing between interpersonal distance (IPD) and peripersonal distance (PPD). Following your suggestion, we have made the following revisions. Firstly, in the first paragraph of introduction, we clearly define and describe interpersonal space and peripersonal space. Then, at the end of the introduction, the innovation point of this paper is added, that is, it combines these two concepts for the first time and discusses their influence on social behavior. Finally,we expanded the discussion on future research direction by incorporating new questions based on your suggestions to highlight how contextual factors may influence our findings.These additions provide a stronger foundation for future studies investigating how interpersonal and peripersonal space interact under different conditions. We sincerely appreciate your constructive feedback, as it has significantly enhanced the theoretical clarity and coherence of our manuscript. Revised version: use underline__ …Social psychology and proxemics have long addressed personal space as the spatial range surrounding the individual (Sommer, 1959; Hall, 1966). The space around the individual may exist in two forms. One is interpersonal distance, the area around the body that individuals maintain between themselves and others during social interactions (Candini et al., 2021). The other one is peripersonal space, which is an adaptive and flexible interface between the body and the environment The space around them represents a mediation zone between the body and the environment, contributing to the organization of social life. For example, when this space is encroached by others, we may feel uncomfortable or may prepare our bodies for defensive responses (Hall, 1966; Coello and Cartaud, 2021). ……… …How has the COVID-19 pandemic and countermeasures against it changed human-human and human-object interactions? Considering the findings of Ariga (2016), one’s personal space extends to his/her belongings, leaving them with an ‘extended personal space’. The present study aimed to examine if the ‘extended personal space’ increased as well as the personal space that has been affected under the pandemic of COVID-19. The fear of infection during the COVID-19 pandemic is closely associated with interpersonal distance. Research indicates that this fear is linked to a tendency to prefer greater interpersonal distance and to underestimate interpersonal space. However, these tendencies stem from subjective perceptions of risk rather than an actual objective risk of infection (Givon-Benjio et al., 2024). On the other hand, personal belongings are more closely related to peripersonal distance. For instance, Lenglart et al. (2023) found that individuals perceive personal items as being more "within reach" compared to other objects, suggesting an expansion in the representation of peripersonal distance. Based on the Coello and Cartaud, they indicated that interpersonal and peripersonal distances are interlinked and together influence social behavior. Therefore, in this study, we innovatively combine these two concepts for the first time to explore the impact of the combination of these two forms of personal space on social actions. Discussion: To dissociate the factor of the pandemic from other potential factors, conducting the study using the same procedure again after the pandemic would be effective. Additionally, future studies should further examine how interpersonal and peripersonal distances interact in different contexts. For example, the level of perceived infectability (i.e., beliefs about one’s own susceptibility to infectious diseases) in 2023 has dropped to the same level as before the COVID-19 pandemic in Japan (Ikeda et al., 2024). Although the number of diagnosed COVID-19 cases remains high, people's subjective risk perception has declined. The potential changes in sensitivity suggested by such reports provide us with numerous possibilities for discussion. Would the effect still emerge when the perceived risk of infection is low? Additionally, would it manifest if participants were asked to place items they do not own? Alternatively, the persistence of the effect—despite the lack of influence of the confederate’s friendliness—suggests that the expansion of peripersonal space during the pandemic might be independent of social cues. Furthermore, the perception of distance may be shaped by long-term societal and technological changes. The widespread use of smartphones and social media in the 2010s might have altered norms around physical proximity and social interaction. Future research could investigate whether personal space norms adapt to such technological shifts and how these changes interact with interpersonal and peripersonal distances. Added references: Candini, M., Battaglia, S., Benassi, M., di Pellegrino, G., & Frassinetti, F. (2021). The physiological correlates of interpersonal space. Scientific Reports , 11 (1), 2611. https://doi.org/10.1038/s41598-021-82223-2 Lenglart, L., Cartaud, A., Quesque, F., Sampaio, A., & Coello, Y. (2023). Object coding in peripersonal space depends on object ownership. Quarterly Journal of Experimental Psychology , 76 (8), 1925-1939. https://doi.org/10.1177/17470218221128306 Givon-Benjio, N., Sokolover, H., Aderka, I. M., Hadad, B. S., & Okon-Singer, H. (2024). Perception of interpersonal distance and social distancing before and during COVID-19 pandemic. Scientific Reports , 14 (1), 4568. https://doi.org/10.1038/s41598-024-55218-y Ikeda A, Sasaki K, Yamada Y.: Evolution of perceived vulnerability to infection in Japan during the COVID-19 pandemic. Qeios. 2024. https://doi.org/10.32388/4CO88Y.4 2. If the authors use the term "personal space" to refer specifically to peripersonal distance, they should explicitly adopt this terminology throughout the manuscript and to update the literature review, especially after the first paragraph. Alternatively, if "personal space" is intended to mean something different from the space surrounding the body, they should clearly define the term. Response： Thank you for confirming the uniformity of terms. In the present study, "personal space" refers to the surrounding space centered on one's body that is not invaded by others in social activities. Closer to the concept of peripersonal space. In addition, the personal space extended by personal belongings is also closer to the "peripersonal space". We clarified the definition of peripersonal space in the first paragraph of introduction and the reference to personal space in our manuscript to ensure the clear and consistent use of terms. Revised version: Social psychology and proxemics have long addressed personal space as the spatial range surrounding the individual ( Sommer, 1959; Hall, 1966). The space around the individual may exist in two forms. One is interpersonal distance, the area around the body that individuals maintain between themselves and others during social interactions (Candini et al., 2021). The other one is peripersonal space, which is an adaptive and flexible interface between the body and the environment, contributing to the organization of social life. For example, when this space is encroached by others, we may feel uncomfortable or may prepare our bodies for defensive responses ( Hall, 1966; Coello and Cartaud, 2021) . In our study, the concept of 'personal space,' as referenced later, aligns more closely with the notion of peripersonal space. This refers to the space immediately surrounding the body, within reach, centered on the individual, and typically protected from intrusion during social interactions. One observed phenomenon is in some school situations where there are desk-mates; after an argument, desk-mates will avoid putting their stationery close to the other’s belongings. It is possible that people develop a tendency to recognize personal belonging as a representation of the self at an early age ( Pedersen, 1973). According to James (1890), the self is the sum of all that he can call his, including all possessions, which gives him the same emotions. Briefly, we regard our possessions as part of ourselves. This intrinsic association between personal belongings and the self-forms the foundation for understanding how external objects, including tools and technologies, can become integrated into one’s sense of self, extending the boundaries of personal space. Studies on body ownership illusions suggest that the integration of external objects or virtual representations into one’s sense of self occurs through multisensory signals, highlighting the neural mechanisms underlying extended personal space (Nilsson & Kalckert, 2021). Is this sense of ownership of objects related to personal space? Ariga (2016) reported that participants placed their own objects at a greater distance from the objects of those who were unfavorable. These findings suggest that individuals’ personal space extended to the space surrounding their belongings (i.e., extended personal space). The placement of such personal belongings can be considered the most significant evidence of an extension of personal space, as it shares the same characteristics with personal space ( Russell & Ward, 1982; Becker, 1973), that the variability depending on the level of familiarity with others. Moreover, recent studies have shown that object ownership influences the representation of peripersonal space. Specifically, self-owned objects within the peripersonal space are processed faster and perceived as more reachable compared to objects owned by others, suggesting an extension of peripersonal space representation around self belongings (Lenglart et al., 2023). This effect is particularly pronounced in individuals with higher interpersonal sensitivity, as their peripersonal space boundaries dynamically adapt in response to social contexts. Further supporting this perspective, Rabellino et al. (2020) highlight that peripersonal space is not only critical for physical interactions with the environment but also closely tied to bodily self-consciousness. They suggest that peripersonal space representation involves multisensory processing and serves both protective and social functions, allowing individuals to dynamically adjust to interactions with others. These findings further support the idea that ownership can extend personal space to include the area surrounding one's possessions, reinforcing the concept of "extended personal space." Added references Lenglart, L., Cartaud, A., Quesque, F., Sampaio, A., & Coello, Y. (2023). Object coding in peripersonal space depends on object ownership. Quarterly Journal of Experimental Psychology , 76 (8), 1925-1939. https://doi.org/10.1177/17470218221128306 Nilsson, M., & Kalckert, A. (2021). Region‐of‐interest analysis approaches in neuroimaging studies of body ownership: An activation likelihood estimation meta‐analysis. European Journal of Neuroscience , 54 (11), 7974-7988. https://doi.org/10.1111/ejn.15534 Rabellino, D., Frewen, P. A., McKinnon, M. C., & Lanius, R. A. (2020). Peripersonal space and bodily self-consciousness: implications for psychological trauma-related disorders. Frontiers in Neuroscience , 14 , 586605. https://doi.org/10.3389/fnins.2020.586605 3. The discussion on interpersonal distance (IPD) during COVID-19 in the introduction is incomplete. While the authors cite studies demonstrating an enlargement of IPD following the pandemic, the paragraph overlooks important nuances. For instance, Iachini et al. (2021), which is already cited, found that the increase in IPD occurred only when subjective risk was high. Similarly, Givon-Benjio et al. (2024) compared data from before and after the outbreak and observed that subjective risk, rather than actual risk (e.g., infection rate), predicted changes in preferred interpersonal distance. Even when the actual risk was high, preferred interpersonal distance remained unchanged. These findings are further supported Cartaud et al., 2020). The introduction should reflect that the enlargement of IPD is not a universal or conclusive effect but is highly dependent on subjective risk levels. While the authors touch on subjective risk in the discussion, particularly when discussing perceived vulnerability to disease (PVD), this concept should receive greater emphasis both in the introduction and discussion to provide a more nuanced understanding of the findings. Cartaud, A., Quesque, F. & Coello, Y. Wearing a face mask against Covid-19 results in a reduction of social distancing. Plos One 15(12), e0243023 (2020 [Ref-3]). Response: We appreciate your insightful comments on the nuanced relationship between interpersonal distance and subjective risk during the COVID-19 pandemic. In response, we have revised the introduction to provide a more balanced discussion on the enlargement of interpersonal distance, emphasizing that this phenomenon is highly dependent on subjective risk levels rather than being a universal or conclusive effect. Specifically, we have incorporated findings from Iachini et al. (2021), Givon-Benjio et al. (2024), and Cartaud et al. (2020) to illustrate how subjective risk plays a crucial role in modulating interpersonal distance. Furthermore, we have strengthened the connection between subjective risk and the concept of extended personal space in the discussion part, which forms the core focus of our study. For details revise, please see "Revised version" Revised version: …Recent studies have reported that interpersonal distance (IPD) increased during the COVID-19 pandemic ( Holt et al. , 2022; Iachini et al. , 2021), and enlarged IPD preferences were predicted to persist beyond the pandemic ( Welsch et al., 2021). However, it is important to note that the enlargement of IPD is not a universal phenomenon. As Iachini et al. (2021) observed, IPD increases only when subjective risk levels are high. Similarly, Givon-Benjio et al. (2024) demonstrated that subjective risk, rather than actual infection risk, predicted changes in preferred IPD. Cartaud et al. (2020) further supported this by showing that even under conditions of high actual risk, individuals’ preferred IPD remained unchanged unless subjective risk was elevated. The results of an experiment in Arabia revealed that in the post-epidemic era, 76% of the participants were already subjectively reluctant to share close physical distance or socially polite touch with others ( Khan et al., 2021). Responding to precautions, the external manifestation is that we have actively increased our physical distance, but in reality, personal space has also expanded accordingly. In several studies related to personal distance in COVID-19, Fini et al. (2021)showed that interpersonal distance is influenced by the perception of realistic threat measured through the COVID-19 threat. In addition, previous research proposed that not only the perception of infection will make the public practice social distancing, but the behavior of practicing social distancing is related to specific individuals as well as related to the social meaning of collective health ( Fazio et al ., 2021). Discussion : Since personal belongings also can be the source of infection through aerosols, the perceived risk of infection may extend to them. It is precisely due to the increased subjective perception of risk that, in the context of COVID-19, the extension of personal belongings comes to represent the characteristics of personal space, and the distance between personal belongings also increases. Participants without sufficient prior information could place their belongings at a distance from the confederate’s belongings to avoid contamination as they were unsure whether the stranger and their belongings were infected with viruses. 4. Supporting the findings is a study that found that COVID-19 is linked to reduction in peripersonal distance, which can help explain why people want to put their belonging further away. Serino, S. et al. Sharpening of peripersonal space during the COVID-19 pandemic. Curr. Biol. 31(14), R889–R890 (2021 [Ref - 4]). Response: Thank you for pointing out this relevant study by Serino et al. (2021). We agree that their findings on the sharpening of peripersonal space during the COVID-19 pandemic provide valuable support for our study. We have incorporated this reference into the discussion section to further explain the increased distance observed between personal belongings. Specifically, we added the following paragraph as in the "Revised version". Revised Version: Several studies have confirmed the increase in personal space during the COVID-19 pandemic and suggested the practice of social distancing attributed to the increase (Fini, Tummolini, and Borghi, 2021; Fazio et al., 2021). Moreover, our study found that the distance between objects increased during the pandemic. Recent findings from studies on the psychological impact of the COVID-19 pandemic provide additional support for our findings. For example, Serino et al. (2021) demonstrated that the pandemic led to a sharpening of peripersonal space boundaries, with individuals adapting their spatial perceptions in response to increased health-related concerns. This phenomenon aligns with our observation that the distance between personal belongings increased during the pandemic. The findings suggest that participants might have subconsciously extended their spatial boundaries to maintain greater safety and reduce perceived risks associated with potential contamination. This adaptation, as highlighted by Serino et al. (2021), may explain why people positioned their belongings farther away from other's during the pandemic. Considering Ariga (2016), personal belongings have the same personal space-like properties as the owner, belongings also maintain their social distance when they are placed. This distance could manifest in the elongated distance of personal belongings. 5. The fact that participants wore face masks should be mentioned earlier in the text, specifically in the Methods section, as it is a relevant procedural detail. Additionally, this should be discussed further in the Discussion section, with reference to studies examining the relationship between mask-wearing and interpersonal or peripersonal distance. Response: We revised the Methods section to include this procedural detail. Additionally, we expanded the Discussion section to explore the potential influence of mask-wearing on interpersonal and peripersonal distance, supported by Cartaud et al.(2020). Revised version: Methods The inclusion criteria were native Japanese or international students who could speak Japanese proficiently. They were paid 1000 yen to agree to participate. All participants were required to wear face masks throughout the experiment as part of standard COVID-19 precautions. Discussion In fact, all valid participants in this study voluntarily wore face masks, which is a routine infection control measure. Beyond compliance, mask-wearing might have also influenced the observed spatial distancing behavior. Research has shown that wearing face masks can alter interpersonal perceptions and decrease interpersonal and peripersonal distances in certain contexts. For example, Cartaud et al. (2020) found that individuals perceived as wearing face masks are considered more trustworthy, leading to reduced physical distance. Similarly, Biggio et al. (2022) reported that mask-wearing shapes interpersonal space by fostering a sense of safety and reducing the need for extended spatial boundaries. In our study, while participants wore face masks during the experiment, the observed increase in distance between personal belongings suggests that compliance with infection control measures and risk-avoidance behaviors might interact differently when participants place objects instead of interacting directly with people. Minor: 6.I found the observations about the role of smartphones and their potential impact on personal space particularly insightful in the discussion. Response: Thank you for your feedback. Our manuscript mentions that smartphones and social media may affect interpersonal distance, but not in conjunction with the concept of interpersonal/intimate distance. To that end, we modified and expanded the section (the modifications here partly same as the response to the question 1, but we're still showing it to you here) : Revised Version: Furthermore, the perception of distance may be shaped by long-term societal and technological changes. The widespread use of smartphones and social media in the 2010s might have altered norms around physical proximity and social interaction. Future research could investigate whether personal space norms adapt to such technological shifts and how these changes interact with interpersonal and peripersonal distances. 7. I suggest reconsidering the inclusion of Figure 3, as it primarily displays the results of a manipulation check, and may not add value to the main narrative of the paper. Reponse: Thank you for your comments. Figure 3 includes part of the results described in the text but also provides a visualization of the data distribution for the manipulation check. To streamline the manuscript, we removed Figure 3 while retaining the textual description, as we believe that the results of the manipulation check are crucial for demonstrating the validity of our experiment design. Revised version: …we calculated the mean favorability for each condition (friendly and unfriendly). The current study examined changes in the distance at which people placed their belongings before and after the COVID-19 outbreak in Japan. The authors employed an ecological task simulating a real-life scenario. The results suggest that the pandemic predicted an enlargement (or expansion) of the distance people placed their belongings from those of a confederate. This effect was not explained by whether the confederate was friendly or hostile, nor by a time*confederate interaction. Overall, I found the study very interesting and with the potential to make a meaningful contribution to existing knowledge. However, there are several areas that warrant further clarification and consideration: 1. A clear distinction should be made between interpersonal distance, which refers to the space between people (as discussed by Hall), and peripersonal distance, the space immediately surrounding the body within reach (as explored by Coello and Cartaud). This differentiation is critical for framing the study's context. The fear of infection during the COVID-19 pandemic is primarily linked to interpersonal distance. Studies have shown that fear of infection correlates with a preference for greater interpersonal distance and an underestimation of interpersonal space. However, these effects are tied to subjective perceptions of risk rather than objective risk of infection (Givon-Benjio et al., 2024). On the other hand, personal belongings conceptually align more with peripersonal distance. For example, Lenglart et al. (2023) demonstrated that personal items are perceived as more "within reach" compared to other objects, indicating an expansion of peripersonal distance representation. The paper by Coello and Cartaud (2021), cited in the introduction, suggests that interpersonal and peripersonal distances are interlinked and together influence social behavior. I recommend moving this discussion to the end of the paragraph, after clarifying the distinction between the two concepts. Additionally, the innovative nature of this study should be explicitly mentioned—specifically, its combination of these two concepts, typically studied independently, to provide novel insights into how they are interconnected. This distinction and integration should also be revisited in the discussion section. Existing literature suggests that the perception of distance is highly context-dependent. For example, would the effect still emerge when the perceived risk is low? Would it manifest if participants were asked to place items they do not own? Or, on the other hand, could the effect persist, as suggested by the lack of influence of the confederate manipulation on the results? Addressing these contextual factors could be done as suggestions for future studies, as answering them may lead to different theoretical and practical conclusions. Lenglart, L., Cartaud, A., Quesque, F., Sampaio, A., & Coello, Y. (2023 [Ref - 1]). Object coding in peripersonal space depends on object ownership. Quarterly Journal of Experimental Psychology, 76(8), 1925-1939. Givon-Benjio, N., Sokolover, H., Aderka, I. M., Hadad, B. S., & Okon-Singer, H. (2024 [Ref -2]). Perception of interpersonal distance and social distancing before and during COVID-19 pandemic. Scientific Reports, 14(1), 4568. Response: Thank you for acknowledging the innovative aspects of our study, and highlighting the importance of clearly distinguishing between interpersonal distance (IPD) and peripersonal distance (PPD). Following your suggestion, we have made the following revisions. Firstly, in the first paragraph of introduction, we clearly define and describe interpersonal space and peripersonal space. Then, at the end of the introduction, the innovation point of this paper is added, that is, it combines these two concepts for the first time and discusses their influence on social behavior. Finally,we expanded the discussion on future research direction by incorporating new questions based on your suggestions to highlight how contextual factors may influence our findings.These additions provide a stronger foundation for future studies investigating how interpersonal and peripersonal space interact under different conditions. We sincerely appreciate your constructive feedback, as it has significantly enhanced the theoretical clarity and coherence of our manuscript. Revised version: use underline__ …Social psychology and proxemics have long addressed personal space as the spatial range surrounding the individual (Sommer, 1959; Hall, 1966). The space around the individual may exist in two forms. One is interpersonal distance, the area around the body that individuals maintain between themselves and others during social interactions (Candini et al., 2021). The other one is peripersonal space, which is an adaptive and flexible interface between the body and the environment The space around them represents a mediation zone between the body and the environment, contributing to the organization of social life. For example, when this space is encroached by others, we may feel uncomfortable or may prepare our bodies for defensive responses (Hall, 1966; Coello and Cartaud, 2021). ……… …How has the COVID-19 pandemic and countermeasures against it changed human-human and human-object interactions? Considering the findings of Ariga (2016), one’s personal space extends to his/her belongings, leaving them with an ‘extended personal space’. The present study aimed to examine if the ‘extended personal space’ increased as well as the personal space that has been affected under the pandemic of COVID-19. The fear of infection during the COVID-19 pandemic is closely associated with interpersonal distance. Research indicates that this fear is linked to a tendency to prefer greater interpersonal distance and to underestimate interpersonal space. However, these tendencies stem from subjective perceptions of risk rather than an actual objective risk of infection (Givon-Benjio et al., 2024). On the other hand, personal belongings are more closely related to peripersonal distance. For instance, Lenglart et al. (2023) found that individuals perceive personal items as being more "within reach" compared to other objects, suggesting an expansion in the representation of peripersonal distance. Based on the Coello and Cartaud, they indicated that interpersonal and peripersonal distances are interlinked and together influence social behavior. Therefore, in this study, we innovatively combine these two concepts for the first time to explore the impact of the combination of these two forms of personal space on social actions. Discussion: To dissociate the factor of the pandemic from other potential factors, conducting the study using the same procedure again after the pandemic would be effective. Additionally, future studies should further examine how interpersonal and peripersonal distances interact in different contexts. For example, the level of perceived infectability (i.e., beliefs about one’s own susceptibility to infectious diseases) in 2023 has dropped to the same level as before the COVID-19 pandemic in Japan (Ikeda et al., 2024). Although the number of diagnosed COVID-19 cases remains high, people's subjective risk perception has declined. The potential changes in sensitivity suggested by such reports provide us with numerous possibilities for discussion. Would the effect still emerge when the perceived risk of infection is low? Additionally, would it manifest if participants were asked to place items they do not own? Alternatively, the persistence of the effect—despite the lack of influence of the confederate’s friendliness—suggests that the expansion of peripersonal space during the pandemic might be independent of social cues. Furthermore, the perception of distance may be shaped by long-term societal and technological changes. The widespread use of smartphones and social media in the 2010s might have altered norms around physical proximity and social interaction. Future research could investigate whether personal space norms adapt to such technological shifts and how these changes interact with interpersonal and peripersonal distances. Added references: Candini, M., Battaglia, S., Benassi, M., di Pellegrino, G., & Frassinetti, F. (2021). The physiological correlates of interpersonal space. Scientific Reports , 11 (1), 2611. https://doi.org/10.1038/s41598-021-82223-2 Lenglart, L., Cartaud, A., Quesque, F., Sampaio, A., & Coello, Y. (2023). Object coding in peripersonal space depends on object ownership. Quarterly Journal of Experimental Psychology , 76 (8), 1925-1939. https://doi.org/10.1177/17470218221128306 Givon-Benjio, N., Sokolover, H., Aderka, I. M., Hadad, B. S., & Okon-Singer, H. (2024). Perception of interpersonal distance and social distancing before and during COVID-19 pandemic. Scientific Reports , 14 (1), 4568. https://doi.org/10.1038/s41598-024-55218-y Ikeda A, Sasaki K, Yamada Y.: Evolution of perceived vulnerability to infection in Japan during the COVID-19 pandemic. Qeios. 2024. https://doi.org/10.32388/4CO88Y.4 2. If the authors use the term "personal space" to refer specifically to peripersonal distance, they should explicitly adopt this terminology throughout the manuscript and to update the literature review, especially after the first paragraph. Alternatively, if "personal space" is intended to mean something different from the space surrounding the body, they should clearly define the term. Response： Thank you for confirming the uniformity of terms. In the present study, "personal space" refers to the surrounding space centered on one's body that is not invaded by others in social activities. Closer to the concept of peripersonal space. In addition, the personal space extended by personal belongings is also closer to the "peripersonal space". We clarified the definition of peripersonal space in the first paragraph of introduction and the reference to personal space in our manuscript to ensure the clear and consistent use of terms. Revised version: Social psychology and proxemics have long addressed personal space as the spatial range surrounding the individual ( Sommer, 1959; Hall, 1966). The space around the individual may exist in two forms. One is interpersonal distance, the area around the body that individuals maintain between themselves and others during social interactions (Candini et al., 2021). The other one is peripersonal space, which is an adaptive and flexible interface between the body and the environment, contributing to the organization of social life. For example, when this space is encroached by others, we may feel uncomfortable or may prepare our bodies for defensive responses ( Hall, 1966; Coello and Cartaud, 2021) . In our study, the concept of 'personal space,' as referenced later, aligns more closely with the notion of peripersonal space. This refers to the space immediately surrounding the body, within reach, centered on the individual, and typically protected from intrusion during social interactions. One observed phenomenon is in some school situations where there are desk-mates; after an argument, desk-mates will avoid putting their stationery close to the other’s belongings. It is possible that people develop a tendency to recognize personal belonging as a representation of the self at an early age ( Pedersen, 1973). According to James (1890), the self is the sum of all that he can call his, including all possessions, which gives him the same emotions. Briefly, we regard our possessions as part of ourselves. This intrinsic association between personal belongings and the self-forms the foundation for understanding how external objects, including tools and technologies, can become integrated into one’s sense of self, extending the boundaries of personal space. Studies on body ownership illusions suggest that the integration of external objects or virtual representations into one’s sense of self occurs through multisensory signals, highlighting the neural mechanisms underlying extended personal space (Nilsson & Kalckert, 2021). Is this sense of ownership of objects related to personal space? Ariga (2016) reported that participants placed their own objects at a greater distance from the objects of those who were unfavorable. These findings suggest that individuals’ personal space extended to the space surrounding their belongings (i.e., extended personal space). The placement of such personal belongings can be considered the most significant evidence of an extension of personal space, as it shares the same characteristics with personal space ( Russell & Ward, 1982; Becker, 1973), that the variability depending on the level of familiarity with others. Moreover, recent studies have shown that object ownership influences the representation of peripersonal space. Specifically, self-owned objects within the peripersonal space are processed faster and perceived as more reachable compared to objects owned by others, suggesting an extension of peripersonal space representation around self belongings (Lenglart et al., 2023). This effect is particularly pronounced in individuals with higher interpersonal sensitivity, as their peripersonal space boundaries dynamically adapt in response to social contexts. Further supporting this perspective, Rabellino et al. (2020) highlight that peripersonal space is not only critical for physical interactions with the environment but also closely tied to bodily self-consciousness. They suggest that peripersonal space representation involves multisensory processing and serves both protective and social functions, allowing individuals to dynamically adjust to interactions with others. These findings further support the idea that ownership can extend personal space to include the area surrounding one's possessions, reinforcing the concept of "extended personal space." Added references Lenglart, L., Cartaud, A., Quesque, F., Sampaio, A., & Coello, Y. (2023). Object coding in peripersonal space depends on object ownership. Quarterly Journal of Experimental Psychology , 76 (8), 1925-1939. https://doi.org/10.1177/17470218221128306 Nilsson, M., & Kalckert, A. (2021). Region‐of‐interest analysis approaches in neuroimaging studies of body ownership: An activation likelihood estimation meta‐analysis. European Journal of Neuroscience , 54 (11), 7974-7988. https://doi.org/10.1111/ejn.15534 Rabellino, D., Frewen, P. A., McKinnon, M. C., & Lanius, R. A. (2020). Peripersonal space and bodily self-consciousness: implications for psychological trauma-related disorders. Frontiers in Neuroscience , 14 , 586605. https://doi.org/10.3389/fnins.2020.586605 3. The discussion on interpersonal distance (IPD) during COVID-19 in the introduction is incomplete. While the authors cite studies demonstrating an enlargement of IPD following the pandemic, the paragraph overlooks important nuances. For instance, Iachini et al. (2021), which is already cited, found that the increase in IPD occurred only when subjective risk was high. Similarly, Givon-Benjio et al. (2024) compared data from before and after the outbreak and observed that subjective risk, rather than actual risk (e.g., infection rate), predicted changes in preferred interpersonal distance. Even when the actual risk was high, preferred interpersonal distance remained unchanged. These findings are further supported Cartaud et al., 2020). The introduction should reflect that the enlargement of IPD is not a universal or conclusive effect but is highly dependent on subjective risk levels. While the authors touch on subjective risk in the discussion, particularly when discussing perceived vulnerability to disease (PVD), this concept should receive greater emphasis both in the introduction and discussion to provide a more nuanced understanding of the findings. Cartaud, A., Quesque, F. & Coello, Y. Wearing a face mask against Covid-19 results in a reduction of social distancing. Plos One 15(12), e0243023 (2020 [Ref-3]). Response: We appreciate your insightful comments on the nuanced relationship between interpersonal distance and subjective risk during the COVID-19 pandemic. In response, we have revised the introduction to provide a more balanced discussion on the enlargement of interpersonal distance, emphasizing that this phenomenon is highly dependent on subjective risk levels rather than being a universal or conclusive effect. Specifically, we have incorporated findings from Iachini et al. (2021), Givon-Benjio et al. (2024), and Cartaud et al. (2020) to illustrate how subjective risk plays a crucial role in modulating interpersonal distance. Furthermore, we have strengthened the connection between subjective risk and the concept of extended personal space in the discussion part, which forms the core focus of our study. For details revise, please see "Revised version" Revised version: …Recent studies have reported that interpersonal distance (IPD) increased during the COVID-19 pandemic ( Holt et al. , 2022; Iachini et al. , 2021), and enlarged IPD preferences were predicted to persist beyond the pandemic ( Welsch et al., 2021). However, it is important to note that the enlargement of IPD is not a universal phenomenon. As Iachini et al. (2021) observed, IPD increases only when subjective risk levels are high. Similarly, Givon-Benjio et al. (2024) demonstrated that subjective risk, rather than actual infection risk, predicted changes in preferred IPD. Cartaud et al. (2020) further supported this by showing that even under conditions of high actual risk, individuals’ preferred IPD remained unchanged unless subjective risk was elevated. The results of an experiment in Arabia revealed that in the post-epidemic era, 76% of the participants were already subjectively reluctant to share close physical distance or socially polite touch with others ( Khan et al., 2021). Responding to precautions, the external manifestation is that we have actively increased our physical distance, but in reality, personal space has also expanded accordingly. In several studies related to personal distance in COVID-19, Fini et al. (2021)showed that interpersonal distance is influenced by the perception of realistic threat measured through the COVID-19 threat. In addition, previous research proposed that not only the perception of infection will make the public practice social distancing, but the behavior of practicing social distancing is related to specific individuals as well as related to the social meaning of collective health ( Fazio et al ., 2021). Discussion : Since personal belongings also can be the source of infection through aerosols, the perceived risk of infection may extend to them. It is precisely due to the increased subjective perception of risk that, in the context of COVID-19, the extension of personal belongings comes to represent the characteristics of personal space, and the distance between personal belongings also increases. Participants without sufficient prior information could place their belongings at a distance from the confederate’s belongings to avoid contamination as they were unsure whether the stranger and their belongings were infected with viruses. 4. Supporting the findings is a study that found that COVID-19 is linked to reduction in peripersonal distance, which can help explain why people want to put their belonging further away. Serino, S. et al. Sharpening of peripersonal space during the COVID-19 pandemic. Curr. Biol. 31(14), R889–R890 (2021 [Ref - 4]). Response: Thank you for pointing out this relevant study by Serino et al. (2021). We agree that their findings on the sharpening of peripersonal space during the COVID-19 pandemic provide valuable support for our study. We have incorporated this reference into the discussion section to further explain the increased distance observed between personal belongings. Specifically, we added the following paragraph as in the "Revised version". Revised Version: Several studies have confirmed the increase in personal space during the COVID-19 pandemic and suggested the practice of social distancing attributed to the increase (Fini, Tummolini, and Borghi, 2021; Fazio et al., 2021). Moreover, our study found that the distance between objects increased during the pandemic. Recent findings from studies on the psychological impact of the COVID-19 pandemic provide additional support for our findings. For example, Serino et al. (2021) demonstrated that the pandemic led to a sharpening of peripersonal space boundaries, with individuals adapting their spatial perceptions in response to increased health-related concerns. This phenomenon aligns with our observation that the distance between personal belongings increased during the pandemic. The findings suggest that participants might have subconsciously extended their spatial boundaries to maintain greater safety and reduce perceived risks associated with potential contamination. This adaptation, as highlighted by Serino et al. (2021), may explain why people positioned their belongings farther away from other's during the pandemic. Considering Ariga (2016), personal belongings have the same personal space-like properties as the owner, belongings also maintain their social distance when they are placed. This distance could manifest in the elongated distance of personal belongings. 5. The fact that participants wore face masks should be mentioned earlier in the text, specifically in the Methods section, as it is a relevant procedural detail. Additionally, this should be discussed further in the Discussion section, with reference to studies examining the relationship between mask-wearing and interpersonal or peripersonal distance. Response: We revised the Methods section to include this procedural detail. Additionally, we expanded the Discussion section to explore the potential influence of mask-wearing on interpersonal and peripersonal distance, supported by Cartaud et al.(2020). Revised version: Methods The inclusion criteria were native Japanese or international students who could speak Japanese proficiently. They were paid 1000 yen to agree to participate. All participants were required to wear face masks throughout the experiment as part of standard COVID-19 precautions. Discussion In fact, all valid participants in this study voluntarily wore face masks, which is a routine infection control measure. Beyond compliance, mask-wearing might have also influenced the observed spatial distancing behavior. Research has shown that wearing face masks can alter interpersonal perceptions and decrease interpersonal and peripersonal distances in certain contexts. For example, Cartaud et al. (2020) found that individuals perceived as wearing face masks are considered more trustworthy, leading to reduced physical distance. Similarly, Biggio et al. (2022) reported that mask-wearing shapes interpersonal space by fostering a sense of safety and reducing the need for extended spatial boundaries. In our study, while participants wore face masks during the experiment, the observed increase in distance between personal belongings suggests that compliance with infection control measures and risk-avoidance behaviors might interact differently when participants place objects instead of interacting directly with people. Minor: 6.I found the observations about the role of smartphones and their potential impact on personal space particularly insightful in the discussion. Response: Thank you for your feedback. Our manuscript mentions that smartphones and social media may affect interpersonal distance, but not in conjunction with the concept of interpersonal/intimate distance. To that end, we modified and expanded the section (the modifications here partly same as the response to the question 1, but we're still showing it to you here) : Revised Version: Furthermore, the perception of distance may be shaped by long-term societal and technological changes. The widespread use of smartphones and social media in the 2010s might have altered norms around physical proximity and social interaction. Future research could investigate whether personal space norms adapt to such technological shifts and how these changes interact with interpersonal and peripersonal distances. 7. I suggest reconsidering the inclusion of Figure 3, as it primarily displays the results of a manipulation check, and may not add value to the main narrative of the paper. Reponse: Thank you for your comments. Figure 3 includes part of the results described in the text but also provides a visualization of the data distribution for the manipulation check. To streamline the manuscript, we removed Figure 3 while retaining the textual description, as we believe that the results of the manipulation check are crucial for demonstrating the validity of our experiment design. Revised version: …we calculated the mean favorability for each condition (friendly and unfriendly). Competing Interests: No competing interests were disclosed. Close Report a concern COMMENT ON THIS REPORT Version 1 VERSION 1 PUBLISHED 20 Feb 2023 Views 0 Cite How to cite this report: Isomura T. Reviewer Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.143432.r259293 ) The direct URL for this report is: https://f1000research.com/articles/12-199/v1#referee-response-259293 NOTE: it is important to ensure the information in square brackets after the title is included in this citation. Close Copy Citation Details Reviewer Report 14 May 2024 Tomoko Isomura , Graduate School of Informatics, Nagoya University, Nagoya, Japan Approved with Reservations VIEWS 0 https://doi.org/10.5256/f1000research.143432.r259293 Summary: This pre-registered study aimed to examine the effect of the COVID-19 pandemic on human behavior, specifically how long people prefer to keep their personal belongings distanced from others. The authors set up a scenario in which participants placed ... Continue reading READ ALL Summary: This pre-registered study aimed to examine the effect of the COVID-19 pandemic on human behavior, specifically how long people prefer to keep their personal belongings distanced from others. The authors set up a scenario in which participants placed their personal belongings on a desk after a confederate had done the same, without being aware of the study's purpose. They measured the physical distance between the belongings of the participant and the confederate. The obtained data were compared with those from a previous study (Ariga, 2016), conducted before the pandemic using identical procedures. The results showed that the distance between belongings in the present study was greater than reported in the previous study. The authors concluded that the pandemic has increased the personal space people maintain, which further extends the distance they keep from others' belongings. Additionally, although the authors manipulated the confederate’s friendliness—a factor that the previous study demonstrated had an effect—this manipulation did not induce any differences in the present study. I found this study interesting, particularly in that the methods they employed were well-designed to capture human’s implicit attitude for the boundaries of self and others. The manuscript is generally well written, and it is valuable that the authors pre-registered this study. However, I have some concerns about this manuscript in its current form, as follows. Firstly, I question whether the terms "extended" or "extension of" personal space accurately represent the phenomenon described. I acknowledge that our representation of the bodily self can be modulated when manipulating objects or interacting with others, potentially resulting in an "extension," enlargement, or prolongation—or even the opposite—of one's peri-personal or personal space. However, the mental attitude of keeping one's belongings separate from others', especially when the objects are placed away from the body (e.g., on a desk when temporarily leaving), does not seem to me to constitute an "extension" of personal space, although I agree that it reflects some processing of self-other boundaries. It would be advantageous if the authors could include additional literature to support this concept, beyond Ariga (2016). On a related but more minor point, the authors state in the second paragraph of the Introduction that Sasaki et al., 2018 demonstrated that a sense of body ownership is conferred to objects. However, I believe that this study is more appropriately interpreted as showing that the sense of "object ownership" is driven by body-related processing, and the authors' interpretation may be somewhat misleading. Secondly, and more importantly, I found it highly challenging to assert that the effect observed by the authors is truly driven by the COVID-19 pandemic, given the limited measures they collected. While I acknowledge the inherent challenges in proving such causation, I suggest that the authors provide more information and/or conduct additional analyses to make the study more persuasive. Firstly, the authors should clearly state the size of the table and the position of the chair, ensuring they are indeed identical to those used in Ariga (2016). The authors should include this information in the main text, not just within a figure. I assume that the relative position of the chairs to the table would affect the participant’s behavior, as people tend to place objects directly in front of where they are seated. Thus, it is essential that these parameters were controlled between the studies. I also suggest the authors provide more information about the confederates, including their sexes and ages, because Ariga (2016) demonstrated that the relationship between the confederates' and participants' sexes had a clear effect on the results. Furthermore, I speculate that the size or number of the participants' belongings could affect the distance measures. It seems that Ariga (2016) considered only the participant’s bag, but what was the case in this study? If the authors have pictures of the placement of the belongings, they might be able to conduct additional analyses that could potentially rule out the influence of the size/number of the participant’s belongings on the findings. Ideally, it would have been valuable if the authors had collected some subjective scales related to the pandemic, such as how afraid the participants were of or how cautious they were about the infection. This could be a subject to consider for future studies. Minor points: In the third paragraph of the Introduction, the authors reference Tootell et al., 2021, as a study that reported an increase in interpersonal distance during the pandemic. However, I believe that this study was conducted before the pandemic. Could it be that the authors intended to cite Holt et al., 2022 instead? The authors should clearly specify the timing of data collection within the Methods section of the main text. Upon reviewing the raw data provided by the authors, I noticed that it includes 70 data. If I understood correctly, there should only be 68 data since 2 participants did not bring any belongings. Please check this. This study did not find any effect of the confederate's friendliness on the participants' behavior. The authors claims that this result is inconsistent with findings from Ariga (2006), potentially due to a ceiling effect. However, since the ANOVA revealed only a main effect of experimental timing and the interaction was not significant, it may be misleading to definitively state that the findings are inconsistent regarding the effect of the confederate's friendliness. Is the work clearly and accurately presented and does it cite the current literature? Yes Is the study design appropriate and is the work technically sound? Partly Are sufficient details of methods and analysis provided to allow replication by others? Partly If applicable, is the statistical analysis and its interpretation appropriate? Partly Are all the source data underlying the results available to ensure full reproducibility? Partly Are the conclusions drawn adequately supported by the results? Partly Competing Interests: No competing interests were disclosed. Reviewer Expertise: experimental psychology; embodied cognition; social cognition I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above. Close READ LESS CITE CITE HOW TO CITE THIS REPORT Isomura T. Reviewer Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.143432.r259293 ) The direct URL for this report is: https://f1000research.com/articles/12-199/v1#referee-response-259293 NOTE: it is important to ensure the information in square brackets after the title is included in all citations of this article. COPY CITATION DETAILS Report a concern Author Response 27 Aug 2024 Kaito Takashima , Graduate School of Human-Environment Studies, Kyushu University, Fukuoka, Japan 27 Aug 2024 Author Response Replies to the comments by Dr.Tomoko Isomura (Graduate School of Informatics, Nagoya University, Nagoya, Japan): Reviewer Comments: “This pre-registered study aimed to examine the effect of the ... Continue reading Replies to the comments by Dr.Tomoko Isomura (Graduate School of Informatics, Nagoya University, Nagoya, Japan): Reviewer Comments: “This pre-registered study aimed to examine the effect of the COVID-19 pandemic on human behavior, specifically how long people prefer to keep their personal belongings distanced from others. The authors set up a scenario in which participants placed their personal belongings on a desk after a confederate had done the same, without being aware of the study's purpose. They measured the physical distance between the belongings of the participant and the confederate. The obtained data were compared with those from a previous study (Ariga, 2016), conducted before the pandemic using identical procedures. The results showed that the distance between belongings in the present study was greater than reported in the previous study. The authors concluded that the pandemic has increased the personal space people maintain, which further extends the distance they keep from others' belongings. Additionally, although the authors manipulated the confederate’s friendliness—a factor that the previous study demonstrated had an effect—this manipulation did not induce any differences in the present study. I found this study interesting, particularly in that the methods they employed were well-designed to capture human’s implicit attitude for the boundaries of self and others. The manuscript is generally well written, and it is valuable that the authors pre-registered this study. However, I have some concerns about this manuscript in its current form, as follows.” “Firstly, I question whether the terms "extended" or "extension of" personal space accurately represent the phenomenon described. I acknowledge that our representation of the bodily self can be modulated when manipulating objects or interacting with others, potentially resulting in an "extension," enlargement, or prolongation—or even the opposite—of one's peri-personal or personal space. However, the mental attitude of keeping one's belongings separate from others', especially when the objects are placed away from the body (e.g., on a desk when temporarily leaving), does not seem to me to constitute an "extension" of personal space, although I agree that it reflects some processing of self-other boundaries. It would be advantageous if the authors could include additional literature to support this concept, beyond Ariga (2016). On a related but more minor point, the authors state in the second paragraph of the Introduction that Sasaki et al., 2018 demonstrated that a sense of body ownership is conferred to objects. However, I believe that this study is more appropriately interpreted as showing that the sense of "object ownership" is driven by body-related processing, and the authors' interpretation may be somewhat misleading.” Author Reply: Thank you very much for your insightful comments. Before starting this study, we extensively debated the differences between the sense of ownership and personal space and territory, ultimately concluding that this phenomenon is related to personal space. Here, we outline our rationale: The most significant evidence that the extended space is part of personal space is its variability depending on the level of familiarity with others. The size of personal space is not fixed; it varies depending on the level of familiarity with others. Ariga (2016) reported that this feature is also reflected in owned objects. Our focus on this feature is why we use the term "personal space." While it is true that the "extension of personal space" shares similar characteristics with personal space in terms of variability based on familiarity with others, we agree with your point that the "extension of personal space" discussed in our study is not entirely the same as "personal space." As you pointed out, concepts such as the sense of ownership and territory are likely relevant to this phenomenon. To prevent readers from misunderstanding the same confusion as you, we have clarified the concept of “extension of personal space” in the original article: The end of the second paragraph in the introduction: “…extended to the space surrounding their belongings (i.e., extended personal space). The placement of such personal belongings can be considered the most significant evidence of an extension of personal space, as it shares the same characteristics with personal space (Russell & Ward, 1982; Becker, 1973), that the variability depending on the level of familiarity with others.” Additional references: Russell, J. A., & Ward, L. M. (1982). Environmental psychology. Annual Review of Psychology, 33, 651–688. https://doi.org/10.1146/annurev.ps.33.020182.003251 Becker, F. D. (1973). Study of spatial markers. Journal of Personality and Social Psychology, 26, 439–445. As for the second point you mentioned about the citation of Sasaki et al (2018), after checking, we agree that this citation is not optimal and potentially misleading here. The argument for this statement is also mentioned later in the paragraph, so we have deleted this sentence. Reviewer Comments: “Secondly, and more importantly, I found it highly challenging to assert that the effect observed by the authors is truly driven by the COVID-19 pandemic, given the limited measures they collected. While I acknowledge the inherent challenges in proving such causation, I suggest that the authors provide more information and/or conduct additional analyses to make the study more persuasive. Firstly, the authors should clearly state the size of the table and the position of the chair, ensuring they are indeed identical to those used in Ariga (2016). The authors should include this information in the main text, not just within a figure. I assume that the relative position of the chairs to the table would affect the participant’s behavior, as people tend to place objects directly in front of where they are seated. Thus, it is essential that these parameters were controlled between the studies. I also suggest the authors provide more information about the confederates, including their sexes and ages, because Ariga (2016) demonstrated that the relationship between the confederates' and participants' sexes had a clear effect on the results.” Author Reply: Thank you very much for pointing out the inadequacies in our description. For the purpose of controlling the possible influence of the experimental setting on the results, in the present experiment, we used a table of exactly the same size as Ariga (2016), and the positions of the chairs and table were exactly the same as in Ariga's (2016) study. Indeed, including these contents in the main text can help readers better eliminate concerns about the impact of experimental settings on the results, so we clearly stated the contents of this part in the main text. That said, we should consider other factors, than COVID-19, like mood, anxiety, or other person-related characteristics. Moreover, in our experiment, the confederates were three graduate male students who took turns according to their schedules. Their average age was 23.6 years old (the confederate in the original experiment was a 21-year-old male). We also added information about the gender and age of the confederates in the original text. Reviewer Comments: “Furthermore, I speculate that the size or number of the participants' belongings could affect the distance measures. It seems that Ariga (2016) considered only the participant’s bag, but what was the case in this study? If the authors have pictures of the placement of the belongings, they might be able to conduct additional analyses that could potentially rule out the influence of the size/number of the participant’s belongings on the findings.” Author Reply: Although we asked participants to come with their bags, we did not force them. Participants came with their bags, jackets, notebooks, and so on. Because we did not record the type of belongings as well as the size of them, it is difficult to analyze the effects of them. Instead, to control the effect of the size of the items on the results, we standardized the measurements by only measuring the minimum distance between two objects and did not include the size of the objects themselves. We believe that with this approach we can minimize the effect of object size on the results and make full use of the sample size. Reviewer Comments: “Ideally, it would have been valuable if the authors had collected some subjective scales related to the pandemic, such as how afraid the participants were of or how cautious they were about the infection. This could be a subject to consider for future studies.” Author Reply: Unfortunately, we did not measure subjective scales related to the pandemic. We added this point in the Discussion section for future research. Instead, the trend of the pandemic was added in the main text, following the other reviewer. Reviewer Comments: Minor points: “In the third paragraph of the Introduction, the authors reference Tootell et al., 2021, as a study that reported an increase in interpersonal distance during the pandemic. However, I believe that this study was conducted before the pandemic. Could it be that the authors intended to cite Holt et al., 2022 instead?” Author Reply: Thank you very much for pointing out our misunderstanding. Although this article (Tootell et al., 2021) was conducted during the period of COVID-19, the conclusion does not indicate the relationship between the increased interpersonal distance and COVID-19. Therefore, we accept your kind suggestion to cite Holt et al. (2022) and add a reference to Lachini et al. (2021) to increase the persuasiveness of the previous study. The details of the references are as follows: Iachini, T., Frassinetti, F., Ruotolo, F., Sbordone, F. L., Ferrara, A., Arioli, M., ... & Ruggiero, G. (2021). Social distance during the COVID-19 pandemic reflects perceived rather than actual risk. International Journal of Environmental Research and Public Health, 18 (11), 5504. Holt, D. J., Zapetis, S. L., Babadi, B., Zimmerman, J., & Tootell, R. B. (2022). Personal space increases during the COVID-19 pandemic in response to real and virtual humans. Frontiers in Psychology, 13 , 952998. We also revised our manuscript. Reviewer Comments: “The authors should clearly specify the timing of data collection within the Methods section of the main text.” Author Reply: Thank you for your advice. Although the experiment period was referred to in the abstract, we added the timeline of data collection in the method- participants part of the main text as follows: The experiment period was from June 10, 2022, to January 23, 2023. Reviewer Comments: “Upon reviewing the raw data provided by the authors, I noticed that it includes 70 data. If I understood correctly, there should only be 68 data since 2 participants did not bring any belongings. Please check this.” Author Reply: What you understand is correct. Two of the participants did not take any of their belongings to take part in the experiment. Therefore, the experimental conditions were not met, and we excluded the data from these two participants. Moreover, we have mentioned the exclusion in the main text as follows: we collected data from 70 participants; of these, two participants were excluded since they did not bring any belongings. Reviewer Comments: “This study did not find any effect of the confederate's friendliness on the participants' behavior. The authors claims that this result is inconsistent with findings from Ariga (2006), potentially due to a ceiling effect. However, since the ANOVA revealed only a main effect of experimental timing and the interaction was not significant, it may be misleading to definitively state that the findings are inconsistent regarding the effect of the confederate's friendliness.” Author Reply: Our study indeed did not find a significant effect of the confederate's friendliness on the participants' behavior, as indicated by the lack of a significant interaction in the ANOVA. We acknowledged this finding and compared it with the results from Ariga (2006), where friendliness did have an effect. In our discussion, we suggested that the inconsistency with Ariga (2006) might be due to a ceiling effect. The ceiling effect suggests that participants may have already reached a maximum level of performance or behavior, making it difficult to observe any additional effect of the confederate's friendliness. While this is a plausible explanation, we agree that it should be presented as a hypothesis rather than a definitive conclusion. To address your concern about the conclusiveness of our statement, we propose revising our discussion to indicate that the findings are suggestive rather than conclusive. Here is the revised statement: “Intriguingly, our study did not find a significant effect of the confederate's friendliness on participants' behavior, as indicated by the lack of a significant interaction effect in the ANOVA. This result appears to be inconsistent with the findings from Ariga (2016). One possible explanation for this discrepancy could be a ceiling effect, where participants' behavior might have already reached its peak, limiting the observable impact of additional friendliness.” Replies to the comments by Dr.Tomoko Isomura (Graduate School of Informatics, Nagoya University, Nagoya, Japan): Reviewer Comments: “This pre-registered study aimed to examine the effect of the COVID-19 pandemic on human behavior, specifically how long people prefer to keep their personal belongings distanced from others. The authors set up a scenario in which participants placed their personal belongings on a desk after a confederate had done the same, without being aware of the study's purpose. They measured the physical distance between the belongings of the participant and the confederate. The obtained data were compared with those from a previous study (Ariga, 2016), conducted before the pandemic using identical procedures. The results showed that the distance between belongings in the present study was greater than reported in the previous study. The authors concluded that the pandemic has increased the personal space people maintain, which further extends the distance they keep from others' belongings. Additionally, although the authors manipulated the confederate’s friendliness—a factor that the previous study demonstrated had an effect—this manipulation did not induce any differences in the present study. I found this study interesting, particularly in that the methods they employed were well-designed to capture human’s implicit attitude for the boundaries of self and others. The manuscript is generally well written, and it is valuable that the authors pre-registered this study. However, I have some concerns about this manuscript in its current form, as follows.” “Firstly, I question whether the terms "extended" or "extension of" personal space accurately represent the phenomenon described. I acknowledge that our representation of the bodily self can be modulated when manipulating objects or interacting with others, potentially resulting in an "extension," enlargement, or prolongation—or even the opposite—of one's peri-personal or personal space. However, the mental attitude of keeping one's belongings separate from others', especially when the objects are placed away from the body (e.g., on a desk when temporarily leaving), does not seem to me to constitute an "extension" of personal space, although I agree that it reflects some processing of self-other boundaries. It would be advantageous if the authors could include additional literature to support this concept, beyond Ariga (2016). On a related but more minor point, the authors state in the second paragraph of the Introduction that Sasaki et al., 2018 demonstrated that a sense of body ownership is conferred to objects. However, I believe that this study is more appropriately interpreted as showing that the sense of "object ownership" is driven by body-related processing, and the authors' interpretation may be somewhat misleading.” Author Reply: Thank you very much for your insightful comments. Before starting this study, we extensively debated the differences between the sense of ownership and personal space and territory, ultimately concluding that this phenomenon is related to personal space. Here, we outline our rationale: The most significant evidence that the extended space is part of personal space is its variability depending on the level of familiarity with others. The size of personal space is not fixed; it varies depending on the level of familiarity with others. Ariga (2016) reported that this feature is also reflected in owned objects. Our focus on this feature is why we use the term "personal space." While it is true that the "extension of personal space" shares similar characteristics with personal space in terms of variability based on familiarity with others, we agree with your point that the "extension of personal space" discussed in our study is not entirely the same as "personal space." As you pointed out, concepts such as the sense of ownership and territory are likely relevant to this phenomenon. To prevent readers from misunderstanding the same confusion as you, we have clarified the concept of “extension of personal space” in the original article: The end of the second paragraph in the introduction: “…extended to the space surrounding their belongings (i.e., extended personal space). The placement of such personal belongings can be considered the most significant evidence of an extension of personal space, as it shares the same characteristics with personal space (Russell & Ward, 1982; Becker, 1973), that the variability depending on the level of familiarity with others.” Additional references: Russell, J. A., & Ward, L. M. (1982). Environmental psychology. Annual Review of Psychology, 33, 651–688. https://doi.org/10.1146/annurev.ps.33.020182.003251 Becker, F. D. (1973). Study of spatial markers. Journal of Personality and Social Psychology, 26, 439–445. As for the second point you mentioned about the citation of Sasaki et al (2018), after checking, we agree that this citation is not optimal and potentially misleading here. The argument for this statement is also mentioned later in the paragraph, so we have deleted this sentence. Reviewer Comments: “Secondly, and more importantly, I found it highly challenging to assert that the effect observed by the authors is truly driven by the COVID-19 pandemic, given the limited measures they collected. While I acknowledge the inherent challenges in proving such causation, I suggest that the authors provide more information and/or conduct additional analyses to make the study more persuasive. Firstly, the authors should clearly state the size of the table and the position of the chair, ensuring they are indeed identical to those used in Ariga (2016). The authors should include this information in the main text, not just within a figure. I assume that the relative position of the chairs to the table would affect the participant’s behavior, as people tend to place objects directly in front of where they are seated. Thus, it is essential that these parameters were controlled between the studies. I also suggest the authors provide more information about the confederates, including their sexes and ages, because Ariga (2016) demonstrated that the relationship between the confederates' and participants' sexes had a clear effect on the results.” Author Reply: Thank you very much for pointing out the inadequacies in our description. For the purpose of controlling the possible influence of the experimental setting on the results, in the present experiment, we used a table of exactly the same size as Ariga (2016), and the positions of the chairs and table were exactly the same as in Ariga's (2016) study. Indeed, including these contents in the main text can help readers better eliminate concerns about the impact of experimental settings on the results, so we clearly stated the contents of this part in the main text. That said, we should consider other factors, than COVID-19, like mood, anxiety, or other person-related characteristics. Moreover, in our experiment, the confederates were three graduate male students who took turns according to their schedules. Their average age was 23.6 years old (the confederate in the original experiment was a 21-year-old male). We also added information about the gender and age of the confederates in the original text. Reviewer Comments: “Furthermore, I speculate that the size or number of the participants' belongings could affect the distance measures. It seems that Ariga (2016) considered only the participant’s bag, but what was the case in this study? If the authors have pictures of the placement of the belongings, they might be able to conduct additional analyses that could potentially rule out the influence of the size/number of the participant’s belongings on the findings.” Author Reply: Although we asked participants to come with their bags, we did not force them. Participants came with their bags, jackets, notebooks, and so on. Because we did not record the type of belongings as well as the size of them, it is difficult to analyze the effects of them. Instead, to control the effect of the size of the items on the results, we standardized the measurements by only measuring the minimum distance between two objects and did not include the size of the objects themselves. We believe that with this approach we can minimize the effect of object size on the results and make full use of the sample size. Reviewer Comments: “Ideally, it would have been valuable if the authors had collected some subjective scales related to the pandemic, such as how afraid the participants were of or how cautious they were about the infection. This could be a subject to consider for future studies.” Author Reply: Unfortunately, we did not measure subjective scales related to the pandemic. We added this point in the Discussion section for future research. Instead, the trend of the pandemic was added in the main text, following the other reviewer. Reviewer Comments: Minor points: “In the third paragraph of the Introduction, the authors reference Tootell et al., 2021, as a study that reported an increase in interpersonal distance during the pandemic. However, I believe that this study was conducted before the pandemic. Could it be that the authors intended to cite Holt et al., 2022 instead?” Author Reply: Thank you very much for pointing out our misunderstanding. Although this article (Tootell et al., 2021) was conducted during the period of COVID-19, the conclusion does not indicate the relationship between the increased interpersonal distance and COVID-19. Therefore, we accept your kind suggestion to cite Holt et al. (2022) and add a reference to Lachini et al. (2021) to increase the persuasiveness of the previous study. The details of the references are as follows: Iachini, T., Frassinetti, F., Ruotolo, F., Sbordone, F. L., Ferrara, A., Arioli, M., ... & Ruggiero, G. (2021). Social distance during the COVID-19 pandemic reflects perceived rather than actual risk. International Journal of Environmental Research and Public Health, 18 (11), 5504. Holt, D. J., Zapetis, S. L., Babadi, B., Zimmerman, J., & Tootell, R. B. (2022). Personal space increases during the COVID-19 pandemic in response to real and virtual humans. Frontiers in Psychology, 13 , 952998. We also revised our manuscript. Reviewer Comments: “The authors should clearly specify the timing of data collection within the Methods section of the main text.” Author Reply: Thank you for your advice. Although the experiment period was referred to in the abstract, we added the timeline of data collection in the method- participants part of the main text as follows: The experiment period was from June 10, 2022, to January 23, 2023. Reviewer Comments: “Upon reviewing the raw data provided by the authors, I noticed that it includes 70 data. If I understood correctly, there should only be 68 data since 2 participants did not bring any belongings. Please check this.” Author Reply: What you understand is correct. Two of the participants did not take any of their belongings to take part in the experiment. Therefore, the experimental conditions were not met, and we excluded the data from these two participants. Moreover, we have mentioned the exclusion in the main text as follows: we collected data from 70 participants; of these, two participants were excluded since they did not bring any belongings. Reviewer Comments: “This study did not find any effect of the confederate's friendliness on the participants' behavior. The authors claims that this result is inconsistent with findings from Ariga (2006), potentially due to a ceiling effect. However, since the ANOVA revealed only a main effect of experimental timing and the interaction was not significant, it may be misleading to definitively state that the findings are inconsistent regarding the effect of the confederate's friendliness.” Author Reply: Our study indeed did not find a significant effect of the confederate's friendliness on the participants' behavior, as indicated by the lack of a significant interaction in the ANOVA. We acknowledged this finding and compared it with the results from Ariga (2006), where friendliness did have an effect. In our discussion, we suggested that the inconsistency with Ariga (2006) might be due to a ceiling effect. The ceiling effect suggests that participants may have already reached a maximum level of performance or behavior, making it difficult to observe any additional effect of the confederate's friendliness. While this is a plausible explanation, we agree that it should be presented as a hypothesis rather than a definitive conclusion. To address your concern about the conclusiveness of our statement, we propose revising our discussion to indicate that the findings are suggestive rather than conclusive. Here is the revised statement: “Intriguingly, our study did not find a significant effect of the confederate's friendliness on participants' behavior, as indicated by the lack of a significant interaction effect in the ANOVA. This result appears to be inconsistent with the findings from Ariga (2016). One possible explanation for this discrepancy could be a ceiling effect, where participants' behavior might have already reached its peak, limiting the observable impact of additional friendliness.” Competing Interests: No competing interests were disclosed. Close Report a concern Respond or Comment COMMENTS ON THIS REPORT Author Response 27 Aug 2024 Kaito Takashima , Graduate School of Human-Environment Studies, Kyushu University, Fukuoka, Japan 27 Aug 2024 Author Response Replies to the comments by Dr.Tomoko Isomura (Graduate School of Informatics, Nagoya University, Nagoya, Japan): Reviewer Comments: “This pre-registered study aimed to examine the effect of the ... Continue reading Replies to the comments by Dr.Tomoko Isomura (Graduate School of Informatics, Nagoya University, Nagoya, Japan): Reviewer Comments: “This pre-registered study aimed to examine the effect of the COVID-19 pandemic on human behavior, specifically how long people prefer to keep their personal belongings distanced from others. The authors set up a scenario in which participants placed their personal belongings on a desk after a confederate had done the same, without being aware of the study's purpose. They measured the physical distance between the belongings of the participant and the confederate. The obtained data were compared with those from a previous study (Ariga, 2016), conducted before the pandemic using identical procedures. The results showed that the distance between belongings in the present study was greater than reported in the previous study. The authors concluded that the pandemic has increased the personal space people maintain, which further extends the distance they keep from others' belongings. Additionally, although the authors manipulated the confederate’s friendliness—a factor that the previous study demonstrated had an effect—this manipulation did not induce any differences in the present study. I found this study interesting, particularly in that the methods they employed were well-designed to capture human’s implicit attitude for the boundaries of self and others. The manuscript is generally well written, and it is valuable that the authors pre-registered this study. However, I have some concerns about this manuscript in its current form, as follows.” “Firstly, I question whether the terms "extended" or "extension of" personal space accurately represent the phenomenon described. I acknowledge that our representation of the bodily self can be modulated when manipulating objects or interacting with others, potentially resulting in an "extension," enlargement, or prolongation—or even the opposite—of one's peri-personal or personal space. However, the mental attitude of keeping one's belongings separate from others', especially when the objects are placed away from the body (e.g., on a desk when temporarily leaving), does not seem to me to constitute an "extension" of personal space, although I agree that it reflects some processing of self-other boundaries. It would be advantageous if the authors could include additional literature to support this concept, beyond Ariga (2016). On a related but more minor point, the authors state in the second paragraph of the Introduction that Sasaki et al., 2018 demonstrated that a sense of body ownership is conferred to objects. However, I believe that this study is more appropriately interpreted as showing that the sense of "object ownership" is driven by body-related processing, and the authors' interpretation may be somewhat misleading.” Author Reply: Thank you very much for your insightful comments. Before starting this study, we extensively debated the differences between the sense of ownership and personal space and territory, ultimately concluding that this phenomenon is related to personal space. Here, we outline our rationale: The most significant evidence that the extended space is part of personal space is its variability depending on the level of familiarity with others. The size of personal space is not fixed; it varies depending on the level of familiarity with others. Ariga (2016) reported that this feature is also reflected in owned objects. Our focus on this feature is why we use the term "personal space." While it is true that the "extension of personal space" shares similar characteristics with personal space in terms of variability based on familiarity with others, we agree with your point that the "extension of personal space" discussed in our study is not entirely the same as "personal space." As you pointed out, concepts such as the sense of ownership and territory are likely relevant to this phenomenon. To prevent readers from misunderstanding the same confusion as you, we have clarified the concept of “extension of personal space” in the original article: The end of the second paragraph in the introduction: “…extended to the space surrounding their belongings (i.e., extended personal space). The placement of such personal belongings can be considered the most significant evidence of an extension of personal space, as it shares the same characteristics with personal space (Russell & Ward, 1982; Becker, 1973), that the variability depending on the level of familiarity with others.” Additional references: Russell, J. A., & Ward, L. M. (1982). Environmental psychology. Annual Review of Psychology, 33, 651–688. https://doi.org/10.1146/annurev.ps.33.020182.003251 Becker, F. D. (1973). Study of spatial markers. Journal of Personality and Social Psychology, 26, 439–445. As for the second point you mentioned about the citation of Sasaki et al (2018), after checking, we agree that this citation is not optimal and potentially misleading here. The argument for this statement is also mentioned later in the paragraph, so we have deleted this sentence. Reviewer Comments: “Secondly, and more importantly, I found it highly challenging to assert that the effect observed by the authors is truly driven by the COVID-19 pandemic, given the limited measures they collected. While I acknowledge the inherent challenges in proving such causation, I suggest that the authors provide more information and/or conduct additional analyses to make the study more persuasive. Firstly, the authors should clearly state the size of the table and the position of the chair, ensuring they are indeed identical to those used in Ariga (2016). The authors should include this information in the main text, not just within a figure. I assume that the relative position of the chairs to the table would affect the participant’s behavior, as people tend to place objects directly in front of where they are seated. Thus, it is essential that these parameters were controlled between the studies. I also suggest the authors provide more information about the confederates, including their sexes and ages, because Ariga (2016) demonstrated that the relationship between the confederates' and participants' sexes had a clear effect on the results.” Author Reply: Thank you very much for pointing out the inadequacies in our description. For the purpose of controlling the possible influence of the experimental setting on the results, in the present experiment, we used a table of exactly the same size as Ariga (2016), and the positions of the chairs and table were exactly the same as in Ariga's (2016) study. Indeed, including these contents in the main text can help readers better eliminate concerns about the impact of experimental settings on the results, so we clearly stated the contents of this part in the main text. That said, we should consider other factors, than COVID-19, like mood, anxiety, or other person-related characteristics. Moreover, in our experiment, the confederates were three graduate male students who took turns according to their schedules. Their average age was 23.6 years old (the confederate in the original experiment was a 21-year-old male). We also added information about the gender and age of the confederates in the original text. Reviewer Comments: “Furthermore, I speculate that the size or number of the participants' belongings could affect the distance measures. It seems that Ariga (2016) considered only the participant’s bag, but what was the case in this study? If the authors have pictures of the placement of the belongings, they might be able to conduct additional analyses that could potentially rule out the influence of the size/number of the participant’s belongings on the findings.” Author Reply: Although we asked participants to come with their bags, we did not force them. Participants came with their bags, jackets, notebooks, and so on. Because we did not record the type of belongings as well as the size of them, it is difficult to analyze the effects of them. Instead, to control the effect of the size of the items on the results, we standardized the measurements by only measuring the minimum distance between two objects and did not include the size of the objects themselves. We believe that with this approach we can minimize the effect of object size on the results and make full use of the sample size. Reviewer Comments: “Ideally, it would have been valuable if the authors had collected some subjective scales related to the pandemic, such as how afraid the participants were of or how cautious they were about the infection. This could be a subject to consider for future studies.” Author Reply: Unfortunately, we did not measure subjective scales related to the pandemic. We added this point in the Discussion section for future research. Instead, the trend of the pandemic was added in the main text, following the other reviewer. Reviewer Comments: Minor points: “In the third paragraph of the Introduction, the authors reference Tootell et al., 2021, as a study that reported an increase in interpersonal distance during the pandemic. However, I believe that this study was conducted before the pandemic. Could it be that the authors intended to cite Holt et al., 2022 instead?” Author Reply: Thank you very much for pointing out our misunderstanding. Although this article (Tootell et al., 2021) was conducted during the period of COVID-19, the conclusion does not indicate the relationship between the increased interpersonal distance and COVID-19. Therefore, we accept your kind suggestion to cite Holt et al. (2022) and add a reference to Lachini et al. (2021) to increase the persuasiveness of the previous study. The details of the references are as follows: Iachini, T., Frassinetti, F., Ruotolo, F., Sbordone, F. L., Ferrara, A., Arioli, M., ... & Ruggiero, G. (2021). Social distance during the COVID-19 pandemic reflects perceived rather than actual risk. International Journal of Environmental Research and Public Health, 18 (11), 5504. Holt, D. J., Zapetis, S. L., Babadi, B., Zimmerman, J., & Tootell, R. B. (2022). Personal space increases during the COVID-19 pandemic in response to real and virtual humans. Frontiers in Psychology, 13 , 952998. We also revised our manuscript. Reviewer Comments: “The authors should clearly specify the timing of data collection within the Methods section of the main text.” Author Reply: Thank you for your advice. Although the experiment period was referred to in the abstract, we added the timeline of data collection in the method- participants part of the main text as follows: The experiment period was from June 10, 2022, to January 23, 2023. Reviewer Comments: “Upon reviewing the raw data provided by the authors, I noticed that it includes 70 data. If I understood correctly, there should only be 68 data since 2 participants did not bring any belongings. Please check this.” Author Reply: What you understand is correct. Two of the participants did not take any of their belongings to take part in the experiment. Therefore, the experimental conditions were not met, and we excluded the data from these two participants. Moreover, we have mentioned the exclusion in the main text as follows: we collected data from 70 participants; of these, two participants were excluded since they did not bring any belongings. Reviewer Comments: “This study did not find any effect of the confederate's friendliness on the participants' behavior. The authors claims that this result is inconsistent with findings from Ariga (2006), potentially due to a ceiling effect. However, since the ANOVA revealed only a main effect of experimental timing and the interaction was not significant, it may be misleading to definitively state that the findings are inconsistent regarding the effect of the confederate's friendliness.” Author Reply: Our study indeed did not find a significant effect of the confederate's friendliness on the participants' behavior, as indicated by the lack of a significant interaction in the ANOVA. We acknowledged this finding and compared it with the results from Ariga (2006), where friendliness did have an effect. In our discussion, we suggested that the inconsistency with Ariga (2006) might be due to a ceiling effect. The ceiling effect suggests that participants may have already reached a maximum level of performance or behavior, making it difficult to observe any additional effect of the confederate's friendliness. While this is a plausible explanation, we agree that it should be presented as a hypothesis rather than a definitive conclusion. To address your concern about the conclusiveness of our statement, we propose revising our discussion to indicate that the findings are suggestive rather than conclusive. Here is the revised statement: “Intriguingly, our study did not find a significant effect of the confederate's friendliness on participants' behavior, as indicated by the lack of a significant interaction effect in the ANOVA. This result appears to be inconsistent with the findings from Ariga (2016). One possible explanation for this discrepancy could be a ceiling effect, where participants' behavior might have already reached its peak, limiting the observable impact of additional friendliness.” Replies to the comments by Dr.Tomoko Isomura (Graduate School of Informatics, Nagoya University, Nagoya, Japan): Reviewer Comments: “This pre-registered study aimed to examine the effect of the COVID-19 pandemic on human behavior, specifically how long people prefer to keep their personal belongings distanced from others. The authors set up a scenario in which participants placed their personal belongings on a desk after a confederate had done the same, without being aware of the study's purpose. They measured the physical distance between the belongings of the participant and the confederate. The obtained data were compared with those from a previous study (Ariga, 2016), conducted before the pandemic using identical procedures. The results showed that the distance between belongings in the present study was greater than reported in the previous study. The authors concluded that the pandemic has increased the personal space people maintain, which further extends the distance they keep from others' belongings. Additionally, although the authors manipulated the confederate’s friendliness—a factor that the previous study demonstrated had an effect—this manipulation did not induce any differences in the present study. I found this study interesting, particularly in that the methods they employed were well-designed to capture human’s implicit attitude for the boundaries of self and others. The manuscript is generally well written, and it is valuable that the authors pre-registered this study. However, I have some concerns about this manuscript in its current form, as follows.” “Firstly, I question whether the terms "extended" or "extension of" personal space accurately represent the phenomenon described. I acknowledge that our representation of the bodily self can be modulated when manipulating objects or interacting with others, potentially resulting in an "extension," enlargement, or prolongation—or even the opposite—of one's peri-personal or personal space. However, the mental attitude of keeping one's belongings separate from others', especially when the objects are placed away from the body (e.g., on a desk when temporarily leaving), does not seem to me to constitute an "extension" of personal space, although I agree that it reflects some processing of self-other boundaries. It would be advantageous if the authors could include additional literature to support this concept, beyond Ariga (2016). On a related but more minor point, the authors state in the second paragraph of the Introduction that Sasaki et al., 2018 demonstrated that a sense of body ownership is conferred to objects. However, I believe that this study is more appropriately interpreted as showing that the sense of "object ownership" is driven by body-related processing, and the authors' interpretation may be somewhat misleading.” Author Reply: Thank you very much for your insightful comments. Before starting this study, we extensively debated the differences between the sense of ownership and personal space and territory, ultimately concluding that this phenomenon is related to personal space. Here, we outline our rationale: The most significant evidence that the extended space is part of personal space is its variability depending on the level of familiarity with others. The size of personal space is not fixed; it varies depending on the level of familiarity with others. Ariga (2016) reported that this feature is also reflected in owned objects. Our focus on this feature is why we use the term "personal space." While it is true that the "extension of personal space" shares similar characteristics with personal space in terms of variability based on familiarity with others, we agree with your point that the "extension of personal space" discussed in our study is not entirely the same as "personal space." As you pointed out, concepts such as the sense of ownership and territory are likely relevant to this phenomenon. To prevent readers from misunderstanding the same confusion as you, we have clarified the concept of “extension of personal space” in the original article: The end of the second paragraph in the introduction: “…extended to the space surrounding their belongings (i.e., extended personal space). The placement of such personal belongings can be considered the most significant evidence of an extension of personal space, as it shares the same characteristics with personal space (Russell & Ward, 1982; Becker, 1973), that the variability depending on the level of familiarity with others.” Additional references: Russell, J. A., & Ward, L. M. (1982). Environmental psychology. Annual Review of Psychology, 33, 651–688. https://doi.org/10.1146/annurev.ps.33.020182.003251 Becker, F. D. (1973). Study of spatial markers. Journal of Personality and Social Psychology, 26, 439–445. As for the second point you mentioned about the citation of Sasaki et al (2018), after checking, we agree that this citation is not optimal and potentially misleading here. The argument for this statement is also mentioned later in the paragraph, so we have deleted this sentence. Reviewer Comments: “Secondly, and more importantly, I found it highly challenging to assert that the effect observed by the authors is truly driven by the COVID-19 pandemic, given the limited measures they collected. While I acknowledge the inherent challenges in proving such causation, I suggest that the authors provide more information and/or conduct additional analyses to make the study more persuasive. Firstly, the authors should clearly state the size of the table and the position of the chair, ensuring they are indeed identical to those used in Ariga (2016). The authors should include this information in the main text, not just within a figure. I assume that the relative position of the chairs to the table would affect the participant’s behavior, as people tend to place objects directly in front of where they are seated. Thus, it is essential that these parameters were controlled between the studies. I also suggest the authors provide more information about the confederates, including their sexes and ages, because Ariga (2016) demonstrated that the relationship between the confederates' and participants' sexes had a clear effect on the results.” Author Reply: Thank you very much for pointing out the inadequacies in our description. For the purpose of controlling the possible influence of the experimental setting on the results, in the present experiment, we used a table of exactly the same size as Ariga (2016), and the positions of the chairs and table were exactly the same as in Ariga's (2016) study. Indeed, including these contents in the main text can help readers better eliminate concerns about the impact of experimental settings on the results, so we clearly stated the contents of this part in the main text. That said, we should consider other factors, than COVID-19, like mood, anxiety, or other person-related characteristics. Moreover, in our experiment, the confederates were three graduate male students who took turns according to their schedules. Their average age was 23.6 years old (the confederate in the original experiment was a 21-year-old male). We also added information about the gender and age of the confederates in the original text. Reviewer Comments: “Furthermore, I speculate that the size or number of the participants' belongings could affect the distance measures. It seems that Ariga (2016) considered only the participant’s bag, but what was the case in this study? If the authors have pictures of the placement of the belongings, they might be able to conduct additional analyses that could potentially rule out the influence of the size/number of the participant’s belongings on the findings.” Author Reply: Although we asked participants to come with their bags, we did not force them. Participants came with their bags, jackets, notebooks, and so on. Because we did not record the type of belongings as well as the size of them, it is difficult to analyze the effects of them. Instead, to control the effect of the size of the items on the results, we standardized the measurements by only measuring the minimum distance between two objects and did not include the size of the objects themselves. We believe that with this approach we can minimize the effect of object size on the results and make full use of the sample size. Reviewer Comments: “Ideally, it would have been valuable if the authors had collected some subjective scales related to the pandemic, such as how afraid the participants were of or how cautious they were about the infection. This could be a subject to consider for future studies.” Author Reply: Unfortunately, we did not measure subjective scales related to the pandemic. We added this point in the Discussion section for future research. Instead, the trend of the pandemic was added in the main text, following the other reviewer. Reviewer Comments: Minor points: “In the third paragraph of the Introduction, the authors reference Tootell et al., 2021, as a study that reported an increase in interpersonal distance during the pandemic. However, I believe that this study was conducted before the pandemic. Could it be that the authors intended to cite Holt et al., 2022 instead?” Author Reply: Thank you very much for pointing out our misunderstanding. Although this article (Tootell et al., 2021) was conducted during the period of COVID-19, the conclusion does not indicate the relationship between the increased interpersonal distance and COVID-19. Therefore, we accept your kind suggestion to cite Holt et al. (2022) and add a reference to Lachini et al. (2021) to increase the persuasiveness of the previous study. The details of the references are as follows: Iachini, T., Frassinetti, F., Ruotolo, F., Sbordone, F. L., Ferrara, A., Arioli, M., ... & Ruggiero, G. (2021). Social distance during the COVID-19 pandemic reflects perceived rather than actual risk. International Journal of Environmental Research and Public Health, 18 (11), 5504. Holt, D. J., Zapetis, S. L., Babadi, B., Zimmerman, J., & Tootell, R. B. (2022). Personal space increases during the COVID-19 pandemic in response to real and virtual humans. Frontiers in Psychology, 13 , 952998. We also revised our manuscript. Reviewer Comments: “The authors should clearly specify the timing of data collection within the Methods section of the main text.” Author Reply: Thank you for your advice. Although the experiment period was referred to in the abstract, we added the timeline of data collection in the method- participants part of the main text as follows: The experiment period was from June 10, 2022, to January 23, 2023. Reviewer Comments: “Upon reviewing the raw data provided by the authors, I noticed that it includes 70 data. If I understood correctly, there should only be 68 data since 2 participants did not bring any belongings. Please check this.” Author Reply: What you understand is correct. Two of the participants did not take any of their belongings to take part in the experiment. Therefore, the experimental conditions were not met, and we excluded the data from these two participants. Moreover, we have mentioned the exclusion in the main text as follows: we collected data from 70 participants; of these, two participants were excluded since they did not bring any belongings. Reviewer Comments: “This study did not find any effect of the confederate's friendliness on the participants' behavior. The authors claims that this result is inconsistent with findings from Ariga (2006), potentially due to a ceiling effect. However, since the ANOVA revealed only a main effect of experimental timing and the interaction was not significant, it may be misleading to definitively state that the findings are inconsistent regarding the effect of the confederate's friendliness.” Author Reply: Our study indeed did not find a significant effect of the confederate's friendliness on the participants' behavior, as indicated by the lack of a significant interaction in the ANOVA. We acknowledged this finding and compared it with the results from Ariga (2006), where friendliness did have an effect. In our discussion, we suggested that the inconsistency with Ariga (2006) might be due to a ceiling effect. The ceiling effect suggests that participants may have already reached a maximum level of performance or behavior, making it difficult to observe any additional effect of the confederate's friendliness. While this is a plausible explanation, we agree that it should be presented as a hypothesis rather than a definitive conclusion. To address your concern about the conclusiveness of our statement, we propose revising our discussion to indicate that the findings are suggestive rather than conclusive. Here is the revised statement: “Intriguingly, our study did not find a significant effect of the confederate's friendliness on participants' behavior, as indicated by the lack of a significant interaction effect in the ANOVA. This result appears to be inconsistent with the findings from Ariga (2016). One possible explanation for this discrepancy could be a ceiling effect, where participants' behavior might have already reached its peak, limiting the observable impact of additional friendliness.” Competing Interests: No competing interests were disclosed. Close Report a concern COMMENT ON THIS REPORT Views 0 Cite How to cite this report: Kroczek LOH. Reviewer Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.143432.r186686 ) The direct URL for this report is: https://f1000research.com/articles/12-199/v1#referee-response-186686 NOTE: it is important to ensure the information in square brackets after the title is included in this citation. Close Copy Citation Details Reviewer Report 24 Jul 2023 Leon O. H Kroczek , University of Regensburg, Regensburg, Germany Not Approved VIEWS 0 https://doi.org/10.5256/f1000research.143432.r186686 Summary: In the present, pre-registered study, participants were asked to place their belongings on a table together with the belongings of a confederate while the physical distance between personal belongings is measured as an outcome variable. These data are then ... Continue reading READ ALL Summary: In the present, pre-registered study, participants were asked to place their belongings on a table together with the belongings of a confederate while the physical distance between personal belongings is measured as an outcome variable. These data are then compared to pre-pandemic data of the same paradigm from Ariga (2016). The authors find an increase in physical distance in the current compared to the original study and interpret these findings in the light of changes of social distances induced by the Covid-19 pandemic. The authors also investigate a within-subject manipulation, i.e. the influence of confederate friendliness on distance between belongings but do not find a significant effect and thus cannot replicate the results of Ariga (2016). Review: I think the present study uses an interesting and unobtrusive way to study interpersonal distance. I also applaud the authors for pre-registering their study. However, one major limitation of this study is that the main comparison is with respect to an unmatched group of participants almost 10 years ago, at a different university. The effects *could* be driven by changes in social distancing introduced by the Covid-19 pandemic, but there are also several other effects that could influence the data. The authors report that the sample had the same sex ratio as the original study, but what about other factors like mood, (social) anxiety, age, other person-related characteristics? Also trivial points, like whether the same kind of belongings were used between studies (jackets or handbags) might have influenced the results (e.g. jackets might fall from the table when placed too close to the border). Some of this is already discussed in the limitations but needs to be highlighted when making claims about Covid-19 related changes of behavior. In my view, it would be much more convincing if the authors could show that distance is influenced by a subjective variable related to perceived vulnerability to Covid-19 (e.g. individual fear of an infection, belief about importance of social distancing as a policy against spread of infection, fear for family members,…, but also belief about whether belonging can be the source of infections) or an objective variable like cases reported in the news, number of active restrictions due to the pandemic, availability of vaccines. It seems also to be the case that standard deviations were bigger in the present study, suggesting a stronger influence of individual characteristics. Anyway, this point needs to be made more clearly throughout the manuscript and should even be reported in the abstract. Side note: Looking in the pre-registration the effect of the within-subject factor “alcohol disinfection” could be also informative about that. As a related point, it would be great to get more information on the state of the pandemic at the test center during the test period. How many new infections were reported during this time? What were the active policies against spread of infections, was the topic very present in the media? I ask this because in Germany, in the second half of 2022 the pandemic was less of a topic than in the years before and there were (almost) no impacts of Covid-19 related restriction in everyday life. I wonder whether similar claims could be made about Japan during this time? In addition, it would strengthen the argument of the authors to describe how the actual distance between persons was related to the distance between belongings. Was the distance in belonging correlated to actual distancing? Please also include more details on the paradigm here: How big was the distance between chairs in the experimental setting? Was it closer or further than a minimum recommended distance? Could this influence the placing of belongings? The authors suggest that a ceiling effect precluded them from finding an effect of friendliness as in Ariga 2016. Looking at the distributions most of the distances were below 60 cm with the table being 150 cm wide (but please state where exactly on the table the belongings of the confederate where located), and original effect being around 10 cm. These data seem to suggest that the effect would have been observable if present. Another interpretation might therefore be that the belongings may not reflect personal space after all (contrary to Ariga, 2016). This should be discussed. Minor: I suggest to change the wording “peacetime” to “pre-pandemic” throughout I had difficulties understanding the first paragraph, maybe consider rephrasing it. Also there is more recent evidence on the relation of peripersonal space and interpersonal distance (e.g. see works of Yann Coello) Is the work clearly and accurately presented and does it cite the current literature? Partly Is the study design appropriate and is the work technically sound? No Are sufficient details of methods and analysis provided to allow replication by others? Partly If applicable, is the statistical analysis and its interpretation appropriate? Yes Are all the source data underlying the results available to ensure full reproducibility? Yes Are the conclusions drawn adequately supported by the results? No Competing Interests: No competing interests were disclosed. Reviewer Expertise: experimental psychology, social interaction research I confirm that I have read this submission and believe that I have an appropriate level of expertise to state that I do not consider it to be of an acceptable scientific standard, for reasons outlined above. Close READ LESS CITE CITE HOW TO CITE THIS REPORT Kroczek LOH. Reviewer Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.143432.r186686 ) The direct URL for this report is: https://f1000research.com/articles/12-199/v1#referee-response-186686 NOTE: it is important to ensure the information in square brackets after the title is included in all citations of this article. COPY CITATION DETAILS Report a concern Author Response 27 Aug 2024 Kaito Takashima , Graduate School of Human-Environment Studies, Kyushu University, Fukuoka, Japan 27 Aug 2024 Author Response Replies to the comments by Dr. Leon O. H Kroczek (University of Regensburg, Regensburg, Germany): Reviewer Comment: “I think the present study uses an interesting and unobtrusive way to ... Continue reading Replies to the comments by Dr. Leon O. H Kroczek (University of Regensburg, Regensburg, Germany): Reviewer Comment: “I think the present study uses an interesting and unobtrusive way to study interpersonal distance. I also applaud the authors for pre-registering their study. However, one major limitation of this study is that the main comparison is with respect to an unmatched group of participants almost 10 years ago, at a different university. The effects *could* be driven by changes in social distancing introduced by the Covid-19 pandemic, but there are also several other effects that could influence the data. The authors report that the sample had the same sex ratio as the original study, but what about other factors like mood, (social) anxiety, age, other person-related characteristics? Also trivial points, like whether the same kind of belongings were used between studies (jackets or handbags) might have influenced the results (e.g. jackets might fall from the table when placed too close to the border). Some of this is already discussed in the limitations but needs to be highlighted when making claims about Covid-19 related changes of behavior.” Author Reply: Thank you for your comments. Unfortunately, the current evidence cannot assess the possibility that differences in data collection year, person-related characteristics, and university might influence the distance between inter-belongings. In addition, although the participants’ belongings were limited to bags in the previous study (Ariga, 2016), in the present study, we did not restrict participants to carry only bags. We agree with your comment that it is important to highlight this information when making claims about COVID-19-related changes in behavior. Thus, in the conclusion part, we added, “…the results show that people significantly increased, with a large effect size, the distance between personal belongings during the COVID-19 pandemic. It is important to note, however, that the results of the present experiment do not fully demonstrate that COVID-19 was the only factor that affected the expanded personal space between belongings.” As we stated in the Discussion section, our hypothesis was that the distance between objects to which the interpersonal relationship expands increased during the COVID-19 period, but we considered COVID-19 as just one possible reason for this. To avoid misunderstanding among readers and other researchers, we adjusted the tone of the descriptions related to the plausible explanations of our results in the Discussion section of the revised manuscript:" ... extended personal space increased during the period of COVID-19 pandemic, but we consider COVID-19 as one of the reasons for this change. " Reviewer Comment: “In my view, it would be much more convincing if the authors could show that distance is influenced by a subjective variable related to perceived vulnerability to Covid-19 (e.g. individual fear of an infection, belief about importance of social distancing as a policy against spread of infection, fear for family members,…, but also belief about whether belonging can be the source of infections) or an objective variable like cases reported in the news, number of active restrictions due to the pandemic, availability of vaccines. It seems also to be the case that standard deviations were bigger in the present study, suggesting a stronger influence of individual characteristics. Anyway, this point needs to be made more clearly throughout the manuscript and should even be reported in the abstract. Side note: Looking in the pre-registration the effect of the within-subject factor “alcohol disinfection” could be also informative about that.” Author Reply: Several studies related to personal distance during COVID-19, such as Fini et al. (2021), have shown that interpersonal distance is influenced by the perception of Realistic Threat, as measured through the COVID-19 threat. Moreover, previous research suggests that the public's practice of social distancing is not solely driven by the perception of infection but also by the social meaning of collective health (Fazio et al., 2021). We have added the following to the third paragraph of the introduction: “... which means that exposed people and objects may carry the coronavirus present in aerosols. Doremalen et al. (2020) compared the survivability of SARS-CoV-2 (leading to COVID-19) and SARS-CoV-1 on different surfaces. They found that the survival time of SARS-CoV-2 on various material surfaces ranged from a few hours to a few days, suggesting that the surface of an item can be a potential pathway for virus transmission. Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) have also mentioned that the virus can be transmitted through direct contact with contaminated surfaces.” We greatly appreciate your suggestion to include these previous research findings in the manuscript and the abstract. This will help clarify to readers that the increased distance between belongings during COVID-19 may be influenced by the perceived threat that objects can also be a source of infection. Regarding the “alcohol disinfection” condition, it belonged to another experiment in our lab. For this experiment, we can only provide the results, which indicate that expanded personal space does not change depending on hand disinfection. Reviewer Comment: “As a related point, it would be great to get more information on the state of the pandemic at the test center during the test period. How many new infections were reported during this time? What were the active policies against spread of infections, was the topic very present in the media? I ask this because in Germany, in the second half of 2022 the pandemic was less of a topic than in the years before and there were (almost) no impacts of Covid-19 related restriction in everyday life. I wonder whether similar claims could be made about Japan during this time?” Author Reply: We utilized Google Trends to track the frequency of the keyword "コロナ" (Japanese term for COVID-19) in Google searches. The data revealed that media coverage of COVID-19 in Japan fluctuated significantly, with the peak occurring at the onset of the pandemic in early 2020. Our experiment took place from June 2022 to January 2023, during which time the final wave of COVID-19 peaked, and media coverage remained high. However, by January 2023, media coverage started to decrease. Additionally, COVID-19-related information was widely disseminated not only through news and entertainment media but also in public places such as restaurants and shopping malls, where social distancing and health and safety measures were prominently displayed. According to Japanese news reports [Please refer to the below links for Image 1 and Image 2] , the number of new COVID-19 infections across Japan exceeded 40,000 per day starting in June 2022, reaching over 100,000 per day by July 2022. This marked the highest number of cases since the initial outbreak of COVID-19 in Japan in 2020. Image 1 Reference link: https://f1000research.s3.amazonaws.com/linked/669428.Image_1.pdf Image 2 Reference link: https://f1000research.s3.amazonaws.com/linked/669429.Image_2.pdf Reviewer Comment: “In addition, it would strengthen the argument of the authors to describe how the actual distance between persons was related to the distance between belongings. Was the distance in belonging correlated to actual distancing?” Author Reply: While we believe that our current findings reflect the physical distance between the confederate and the participant, we did not measure this distance during the actual experiment. Instead, we fixed their physical distance to eliminate any potential influence that physical distance might have had on the placement of objects, as it could have affected the results. Reviewer Comment: “Please also include more details on the paradigm here: How big was the distance between chairs in the experimental setting? Was it closer or further than a minimum recommended distance? Could this influence the placing of belongings?” Author Reply: The distance between the two chairs was approximately 30-40 cm, significantly less than the recommended social distancing measure of 2 meters due to the constraints of the experiment room's size and layout. The small distance between chairs may have created a sense of social anxiety and constriction at the beginning, making participants place belongings farther away to alleviate seated proximity in subsequent place sessions. No studies have been done to illustrate the effect of physical proximity on the unraveling of the distance between items. We added this part of the influence of chair distance on the distance of placing objects in the limitation part. "... as they were unsure whether the stranger and their belongings were infected with viruses. Moreover, some previous studies declared that the confined spaces may enhance the feeling of personal space invasion, thereby increasing psychological stress and anxiety (Aiello et al ., 1977; Evans, & Wener, 2007). In the present study, for strict replication and fair comparison, the chair distance was set to be the same as in the original experiment conducted in the pre-pandemic period, but the small distance between chairs may have created a sense of social anxiety and constriction at the beginning, making participants place belongings farther away to alleviate seated proximity in subsequent place sessions. No studies that have been done to illustrate the effect of physical proximity on the unraveling of the distance between items. "... and sat next to the confederate’s chair. The distance between two chairs was roughly 30-40 cm." in the Procedure section. Reviewer Comment: “The authors suggest that a ceiling effect precluded them from finding an effect of friendliness as in Ariga 2016. Looking at the distributions most of the distances were below 60 cm with the table being 150 cm wide (but please state where exactly on the table the belongings of the confederate where located), and original effect being around 10 cm. These data seem to suggest that the effect would have been observable if present. Another interpretation might therefore be that the belongings may not reflect personal space after all (contrary to Ariga, 2016). This should be discussed.” Author Reply: Thank you for your insightful comment. Our manuscript lacked a crucial piece of information: the size of the confederate's belongings, which is approximately 36 cm wide. We have now included this detail in our manuscript. Although the confederate experimenters tried to place their belongings as far as possible to the left corner of the desks, the space left for the participants was estimated to be around 100-110 cm. Additionally, the maximum distance between the belongings would be approximately 60 cm, assuming the participant's belongings were about 40 cm wide. Attempting to increase the distance by 10 cm from the unfriendly confederate's belongings to the average brings it close to the maximum possible distance. Participants might have avoided placing their belongings in the corners due to concerns about them falling. We believe that if the desks had been longer, participants could have placed their belongings further from the unfriendly confederate's belongings without the risk of them falling. Based on this context, we interpreted the results as being influenced by a ceiling effect. Your comment helped us identify and address this missing information. Reviewer Comment: Minor: “I suggest to change the wording “peacetime” to “pre-pandemic” throughout.” Author Reply: We changed it to “pre-pandemic”. Reviewer Comment: “I had difficulties understanding the first paragraph, maybe consider rephrasing it. Also there is more recent evidence on the relation of peripersonal space and interpersonal distance (e.g. see works of Yann Coello)” Author Reply: Thank you for your comments. We have rewritten the first paragraph and added new studies to help clarify our logic for you and the readers. “Social psychology and proxemics have long addressed personal space as the spatial range surrounding the individual (Sommer, 1959; Hall, 1966). The space around them represents a mediation zone between the body and the environment, contributing to the organization of social life. For example, when this space is encroached by others, we may feel uncomfortable or may prepare our bodies for defensive responses (Hall, 1966; Coello and Cartaud, 2021). However, the center of personal space is oneself, but it is not restricted to the physical body; much evidence proposed that the concept of self is expanding in space and timeline. For example, the ‘cutaneous rabbit’ can be felt not only on one’s body but also on an object that one is grasping (Miyazaki et al., 2010). The line of sight away from the eye can still be perceived as exerting force on the object (Guterstam et al., 2019). Furthermore, the extension of body representations to objects has been observed in neuroscience (Iriki et al., 1996). As a result, personal space boundaries also expand with the extension of body perception.” Replies to the comments by Dr. Leon O. H Kroczek (University of Regensburg, Regensburg, Germany): Reviewer Comment: “I think the present study uses an interesting and unobtrusive way to study interpersonal distance. I also applaud the authors for pre-registering their study. However, one major limitation of this study is that the main comparison is with respect to an unmatched group of participants almost 10 years ago, at a different university. The effects *could* be driven by changes in social distancing introduced by the Covid-19 pandemic, but there are also several other effects that could influence the data. The authors report that the sample had the same sex ratio as the original study, but what about other factors like mood, (social) anxiety, age, other person-related characteristics? Also trivial points, like whether the same kind of belongings were used between studies (jackets or handbags) might have influenced the results (e.g. jackets might fall from the table when placed too close to the border). Some of this is already discussed in the limitations but needs to be highlighted when making claims about Covid-19 related changes of behavior.” Author Reply: Thank you for your comments. Unfortunately, the current evidence cannot assess the possibility that differences in data collection year, person-related characteristics, and university might influence the distance between inter-belongings. In addition, although the participants’ belongings were limited to bags in the previous study (Ariga, 2016), in the present study, we did not restrict participants to carry only bags. We agree with your comment that it is important to highlight this information when making claims about COVID-19-related changes in behavior. Thus, in the conclusion part, we added, “…the results show that people significantly increased, with a large effect size, the distance between personal belongings during the COVID-19 pandemic. It is important to note, however, that the results of the present experiment do not fully demonstrate that COVID-19 was the only factor that affected the expanded personal space between belongings.” As we stated in the Discussion section, our hypothesis was that the distance between objects to which the interpersonal relationship expands increased during the COVID-19 period, but we considered COVID-19 as just one possible reason for this. To avoid misunderstanding among readers and other researchers, we adjusted the tone of the descriptions related to the plausible explanations of our results in the Discussion section of the revised manuscript:" ... extended personal space increased during the period of COVID-19 pandemic, but we consider COVID-19 as one of the reasons for this change. " Reviewer Comment: “In my view, it would be much more convincing if the authors could show that distance is influenced by a subjective variable related to perceived vulnerability to Covid-19 (e.g. individual fear of an infection, belief about importance of social distancing as a policy against spread of infection, fear for family members,…, but also belief about whether belonging can be the source of infections) or an objective variable like cases reported in the news, number of active restrictions due to the pandemic, availability of vaccines. It seems also to be the case that standard deviations were bigger in the present study, suggesting a stronger influence of individual characteristics. Anyway, this point needs to be made more clearly throughout the manuscript and should even be reported in the abstract. Side note: Looking in the pre-registration the effect of the within-subject factor “alcohol disinfection” could be also informative about that.” Author Reply: Several studies related to personal distance during COVID-19, such as Fini et al. (2021), have shown that interpersonal distance is influenced by the perception of Realistic Threat, as measured through the COVID-19 threat. Moreover, previous research suggests that the public's practice of social distancing is not solely driven by the perception of infection but also by the social meaning of collective health (Fazio et al., 2021). We have added the following to the third paragraph of the introduction: “... which means that exposed people and objects may carry the coronavirus present in aerosols. Doremalen et al. (2020) compared the survivability of SARS-CoV-2 (leading to COVID-19) and SARS-CoV-1 on different surfaces. They found that the survival time of SARS-CoV-2 on various material surfaces ranged from a few hours to a few days, suggesting that the surface of an item can be a potential pathway for virus transmission. Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) have also mentioned that the virus can be transmitted through direct contact with contaminated surfaces.” We greatly appreciate your suggestion to include these previous research findings in the manuscript and the abstract. This will help clarify to readers that the increased distance between belongings during COVID-19 may be influenced by the perceived threat that objects can also be a source of infection. Regarding the “alcohol disinfection” condition, it belonged to another experiment in our lab. For this experiment, we can only provide the results, which indicate that expanded personal space does not change depending on hand disinfection. Reviewer Comment: “As a related point, it would be great to get more information on the state of the pandemic at the test center during the test period. How many new infections were reported during this time? What were the active policies against spread of infections, was the topic very present in the media? I ask this because in Germany, in the second half of 2022 the pandemic was less of a topic than in the years before and there were (almost) no impacts of Covid-19 related restriction in everyday life. I wonder whether similar claims could be made about Japan during this time?” Author Reply: We utilized Google Trends to track the frequency of the keyword "コロナ" (Japanese term for COVID-19) in Google searches. The data revealed that media coverage of COVID-19 in Japan fluctuated significantly, with the peak occurring at the onset of the pandemic in early 2020. Our experiment took place from June 2022 to January 2023, during which time the final wave of COVID-19 peaked, and media coverage remained high. However, by January 2023, media coverage started to decrease. Additionally, COVID-19-related information was widely disseminated not only through news and entertainment media but also in public places such as restaurants and shopping malls, where social distancing and health and safety measures were prominently displayed. According to Japanese news reports [Please refer to the below links for Image 1 and Image 2] , the number of new COVID-19 infections across Japan exceeded 40,000 per day starting in June 2022, reaching over 100,000 per day by July 2022. This marked the highest number of cases since the initial outbreak of COVID-19 in Japan in 2020. Image 1 Reference link: https://f1000research.s3.amazonaws.com/linked/669428.Image_1.pdf Image 2 Reference link: https://f1000research.s3.amazonaws.com/linked/669429.Image_2.pdf Reviewer Comment: “In addition, it would strengthen the argument of the authors to describe how the actual distance between persons was related to the distance between belongings. Was the distance in belonging correlated to actual distancing?” Author Reply: While we believe that our current findings reflect the physical distance between the confederate and the participant, we did not measure this distance during the actual experiment. Instead, we fixed their physical distance to eliminate any potential influence that physical distance might have had on the placement of objects, as it could have affected the results. Reviewer Comment: “Please also include more details on the paradigm here: How big was the distance between chairs in the experimental setting? Was it closer or further than a minimum recommended distance? Could this influence the placing of belongings?” Author Reply: The distance between the two chairs was approximately 30-40 cm, significantly less than the recommended social distancing measure of 2 meters due to the constraints of the experiment room's size and layout. The small distance between chairs may have created a sense of social anxiety and constriction at the beginning, making participants place belongings farther away to alleviate seated proximity in subsequent place sessions. No studies have been done to illustrate the effect of physical proximity on the unraveling of the distance between items. We added this part of the influence of chair distance on the distance of placing objects in the limitation part. "... as they were unsure whether the stranger and their belongings were infected with viruses. Moreover, some previous studies declared that the confined spaces may enhance the feeling of personal space invasion, thereby increasing psychological stress and anxiety (Aiello et al ., 1977; Evans, & Wener, 2007). In the present study, for strict replication and fair comparison, the chair distance was set to be the same as in the original experiment conducted in the pre-pandemic period, but the small distance between chairs may have created a sense of social anxiety and constriction at the beginning, making participants place belongings farther away to alleviate seated proximity in subsequent place sessions. No studies that have been done to illustrate the effect of physical proximity on the unraveling of the distance between items. "... and sat next to the confederate’s chair. The distance between two chairs was roughly 30-40 cm." in the Procedure section. Reviewer Comment: “The authors suggest that a ceiling effect precluded them from finding an effect of friendliness as in Ariga 2016. Looking at the distributions most of the distances were below 60 cm with the table being 150 cm wide (but please state where exactly on the table the belongings of the confederate where located), and original effect being around 10 cm. These data seem to suggest that the effect would have been observable if present. Another interpretation might therefore be that the belongings may not reflect personal space after all (contrary to Ariga, 2016). This should be discussed.” Author Reply: Thank you for your insightful comment. Our manuscript lacked a crucial piece of information: the size of the confederate's belongings, which is approximately 36 cm wide. We have now included this detail in our manuscript. Although the confederate experimenters tried to place their belongings as far as possible to the left corner of the desks, the space left for the participants was estimated to be around 100-110 cm. Additionally, the maximum distance between the belongings would be approximately 60 cm, assuming the participant's belongings were about 40 cm wide. Attempting to increase the distance by 10 cm from the unfriendly confederate's belongings to the average brings it close to the maximum possible distance. Participants might have avoided placing their belongings in the corners due to concerns about them falling. We believe that if the desks had been longer, participants could have placed their belongings further from the unfriendly confederate's belongings without the risk of them falling. Based on this context, we interpreted the results as being influenced by a ceiling effect. Your comment helped us identify and address this missing information. Reviewer Comment: Minor: “I suggest to change the wording “peacetime” to “pre-pandemic” throughout.” Author Reply: We changed it to “pre-pandemic”. Reviewer Comment: “I had difficulties understanding the first paragraph, maybe consider rephrasing it. Also there is more recent evidence on the relation of peripersonal space and interpersonal distance (e.g. see works of Yann Coello)” Author Reply: Thank you for your comments. We have rewritten the first paragraph and added new studies to help clarify our logic for you and the readers. “Social psychology and proxemics have long addressed personal space as the spatial range surrounding the individual (Sommer, 1959; Hall, 1966). The space around them represents a mediation zone between the body and the environment, contributing to the organization of social life. For example, when this space is encroached by others, we may feel uncomfortable or may prepare our bodies for defensive responses (Hall, 1966; Coello and Cartaud, 2021). However, the center of personal space is oneself, but it is not restricted to the physical body; much evidence proposed that the concept of self is expanding in space and timeline. For example, the ‘cutaneous rabbit’ can be felt not only on one’s body but also on an object that one is grasping (Miyazaki et al., 2010). The line of sight away from the eye can still be perceived as exerting force on the object (Guterstam et al., 2019). Furthermore, the extension of body representations to objects has been observed in neuroscience (Iriki et al., 1996). As a result, personal space boundaries also expand with the extension of body perception.” Competing Interests: No competing interests were disclosed. Close Report a concern Respond or Comment COMMENTS ON THIS REPORT Author Response 27 Aug 2024 Kaito Takashima , Graduate School of Human-Environment Studies, Kyushu University, Fukuoka, Japan 27 Aug 2024 Author Response Replies to the comments by Dr. Leon O. H Kroczek (University of Regensburg, Regensburg, Germany): Reviewer Comment: “I think the present study uses an interesting and unobtrusive way to ... Continue reading Replies to the comments by Dr. Leon O. H Kroczek (University of Regensburg, Regensburg, Germany): Reviewer Comment: “I think the present study uses an interesting and unobtrusive way to study interpersonal distance. I also applaud the authors for pre-registering their study. However, one major limitation of this study is that the main comparison is with respect to an unmatched group of participants almost 10 years ago, at a different university. The effects *could* be driven by changes in social distancing introduced by the Covid-19 pandemic, but there are also several other effects that could influence the data. The authors report that the sample had the same sex ratio as the original study, but what about other factors like mood, (social) anxiety, age, other person-related characteristics? Also trivial points, like whether the same kind of belongings were used between studies (jackets or handbags) might have influenced the results (e.g. jackets might fall from the table when placed too close to the border). Some of this is already discussed in the limitations but needs to be highlighted when making claims about Covid-19 related changes of behavior.” Author Reply: Thank you for your comments. Unfortunately, the current evidence cannot assess the possibility that differences in data collection year, person-related characteristics, and university might influence the distance between inter-belongings. In addition, although the participants’ belongings were limited to bags in the previous study (Ariga, 2016), in the present study, we did not restrict participants to carry only bags. We agree with your comment that it is important to highlight this information when making claims about COVID-19-related changes in behavior. Thus, in the conclusion part, we added, “…the results show that people significantly increased, with a large effect size, the distance between personal belongings during the COVID-19 pandemic. It is important to note, however, that the results of the present experiment do not fully demonstrate that COVID-19 was the only factor that affected the expanded personal space between belongings.” As we stated in the Discussion section, our hypothesis was that the distance between objects to which the interpersonal relationship expands increased during the COVID-19 period, but we considered COVID-19 as just one possible reason for this. To avoid misunderstanding among readers and other researchers, we adjusted the tone of the descriptions related to the plausible explanations of our results in the Discussion section of the revised manuscript:" ... extended personal space increased during the period of COVID-19 pandemic, but we consider COVID-19 as one of the reasons for this change. " Reviewer Comment: “In my view, it would be much more convincing if the authors could show that distance is influenced by a subjective variable related to perceived vulnerability to Covid-19 (e.g. individual fear of an infection, belief about importance of social distancing as a policy against spread of infection, fear for family members,…, but also belief about whether belonging can be the source of infections) or an objective variable like cases reported in the news, number of active restrictions due to the pandemic, availability of vaccines. It seems also to be the case that standard deviations were bigger in the present study, suggesting a stronger influence of individual characteristics. Anyway, this point needs to be made more clearly throughout the manuscript and should even be reported in the abstract. Side note: Looking in the pre-registration the effect of the within-subject factor “alcohol disinfection” could be also informative about that.” Author Reply: Several studies related to personal distance during COVID-19, such as Fini et al. (2021), have shown that interpersonal distance is influenced by the perception of Realistic Threat, as measured through the COVID-19 threat. Moreover, previous research suggests that the public's practice of social distancing is not solely driven by the perception of infection but also by the social meaning of collective health (Fazio et al., 2021). We have added the following to the third paragraph of the introduction: “... which means that exposed people and objects may carry the coronavirus present in aerosols. Doremalen et al. (2020) compared the survivability of SARS-CoV-2 (leading to COVID-19) and SARS-CoV-1 on different surfaces. They found that the survival time of SARS-CoV-2 on various material surfaces ranged from a few hours to a few days, suggesting that the surface of an item can be a potential pathway for virus transmission. Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) have also mentioned that the virus can be transmitted through direct contact with contaminated surfaces.” We greatly appreciate your suggestion to include these previous research findings in the manuscript and the abstract. This will help clarify to readers that the increased distance between belongings during COVID-19 may be influenced by the perceived threat that objects can also be a source of infection. Regarding the “alcohol disinfection” condition, it belonged to another experiment in our lab. For this experiment, we can only provide the results, which indicate that expanded personal space does not change depending on hand disinfection. Reviewer Comment: “As a related point, it would be great to get more information on the state of the pandemic at the test center during the test period. How many new infections were reported during this time? What were the active policies against spread of infections, was the topic very present in the media? I ask this because in Germany, in the second half of 2022 the pandemic was less of a topic than in the years before and there were (almost) no impacts of Covid-19 related restriction in everyday life. I wonder whether similar claims could be made about Japan during this time?” Author Reply: We utilized Google Trends to track the frequency of the keyword "コロナ" (Japanese term for COVID-19) in Google searches. The data revealed that media coverage of COVID-19 in Japan fluctuated significantly, with the peak occurring at the onset of the pandemic in early 2020. Our experiment took place from June 2022 to January 2023, during which time the final wave of COVID-19 peaked, and media coverage remained high. However, by January 2023, media coverage started to decrease. Additionally, COVID-19-related information was widely disseminated not only through news and entertainment media but also in public places such as restaurants and shopping malls, where social distancing and health and safety measures were prominently displayed. According to Japanese news reports [Please refer to the below links for Image 1 and Image 2] , the number of new COVID-19 infections across Japan exceeded 40,000 per day starting in June 2022, reaching over 100,000 per day by July 2022. This marked the highest number of cases since the initial outbreak of COVID-19 in Japan in 2020. Image 1 Reference link: https://f1000research.s3.amazonaws.com/linked/669428.Image_1.pdf Image 2 Reference link: https://f1000research.s3.amazonaws.com/linked/669429.Image_2.pdf Reviewer Comment: “In addition, it would strengthen the argument of the authors to describe how the actual distance between persons was related to the distance between belongings. Was the distance in belonging correlated to actual distancing?” Author Reply: While we believe that our current findings reflect the physical distance between the confederate and the participant, we did not measure this distance during the actual experiment. Instead, we fixed their physical distance to eliminate any potential influence that physical distance might have had on the placement of objects, as it could have affected the results. Reviewer Comment: “Please also include more details on the paradigm here: How big was the distance between chairs in the experimental setting? Was it closer or further than a minimum recommended distance? Could this influence the placing of belongings?” Author Reply: The distance between the two chairs was approximately 30-40 cm, significantly less than the recommended social distancing measure of 2 meters due to the constraints of the experiment room's size and layout. The small distance between chairs may have created a sense of social anxiety and constriction at the beginning, making participants place belongings farther away to alleviate seated proximity in subsequent place sessions. No studies have been done to illustrate the effect of physical proximity on the unraveling of the distance between items. We added this part of the influence of chair distance on the distance of placing objects in the limitation part. "... as they were unsure whether the stranger and their belongings were infected with viruses. Moreover, some previous studies declared that the confined spaces may enhance the feeling of personal space invasion, thereby increasing psychological stress and anxiety (Aiello et al ., 1977; Evans, & Wener, 2007). In the present study, for strict replication and fair comparison, the chair distance was set to be the same as in the original experiment conducted in the pre-pandemic period, but the small distance between chairs may have created a sense of social anxiety and constriction at the beginning, making participants place belongings farther away to alleviate seated proximity in subsequent place sessions. No studies that have been done to illustrate the effect of physical proximity on the unraveling of the distance between items. "... and sat next to the confederate’s chair. The distance between two chairs was roughly 30-40 cm." in the Procedure section. Reviewer Comment: “The authors suggest that a ceiling effect precluded them from finding an effect of friendliness as in Ariga 2016. Looking at the distributions most of the distances were below 60 cm with the table being 150 cm wide (but please state where exactly on the table the belongings of the confederate where located), and original effect being around 10 cm. These data seem to suggest that the effect would have been observable if present. Another interpretation might therefore be that the belongings may not reflect personal space after all (contrary to Ariga, 2016). This should be discussed.” Author Reply: Thank you for your insightful comment. Our manuscript lacked a crucial piece of information: the size of the confederate's belongings, which is approximately 36 cm wide. We have now included this detail in our manuscript. Although the confederate experimenters tried to place their belongings as far as possible to the left corner of the desks, the space left for the participants was estimated to be around 100-110 cm. Additionally, the maximum distance between the belongings would be approximately 60 cm, assuming the participant's belongings were about 40 cm wide. Attempting to increase the distance by 10 cm from the unfriendly confederate's belongings to the average brings it close to the maximum possible distance. Participants might have avoided placing their belongings in the corners due to concerns about them falling. We believe that if the desks had been longer, participants could have placed their belongings further from the unfriendly confederate's belongings without the risk of them falling. Based on this context, we interpreted the results as being influenced by a ceiling effect. Your comment helped us identify and address this missing information. Reviewer Comment: Minor: “I suggest to change the wording “peacetime” to “pre-pandemic” throughout.” Author Reply: We changed it to “pre-pandemic”. Reviewer Comment: “I had difficulties understanding the first paragraph, maybe consider rephrasing it. Also there is more recent evidence on the relation of peripersonal space and interpersonal distance (e.g. see works of Yann Coello)” Author Reply: Thank you for your comments. We have rewritten the first paragraph and added new studies to help clarify our logic for you and the readers. “Social psychology and proxemics have long addressed personal space as the spatial range surrounding the individual (Sommer, 1959; Hall, 1966). The space around them represents a mediation zone between the body and the environment, contributing to the organization of social life. For example, when this space is encroached by others, we may feel uncomfortable or may prepare our bodies for defensive responses (Hall, 1966; Coello and Cartaud, 2021). However, the center of personal space is oneself, but it is not restricted to the physical body; much evidence proposed that the concept of self is expanding in space and timeline. For example, the ‘cutaneous rabbit’ can be felt not only on one’s body but also on an object that one is grasping (Miyazaki et al., 2010). The line of sight away from the eye can still be perceived as exerting force on the object (Guterstam et al., 2019). Furthermore, the extension of body representations to objects has been observed in neuroscience (Iriki et al., 1996). As a result, personal space boundaries also expand with the extension of body perception.” Replies to the comments by Dr. Leon O. H Kroczek (University of Regensburg, Regensburg, Germany): Reviewer Comment: “I think the present study uses an interesting and unobtrusive way to study interpersonal distance. I also applaud the authors for pre-registering their study. However, one major limitation of this study is that the main comparison is with respect to an unmatched group of participants almost 10 years ago, at a different university. The effects *could* be driven by changes in social distancing introduced by the Covid-19 pandemic, but there are also several other effects that could influence the data. The authors report that the sample had the same sex ratio as the original study, but what about other factors like mood, (social) anxiety, age, other person-related characteristics? Also trivial points, like whether the same kind of belongings were used between studies (jackets or handbags) might have influenced the results (e.g. jackets might fall from the table when placed too close to the border). Some of this is already discussed in the limitations but needs to be highlighted when making claims about Covid-19 related changes of behavior.” Author Reply: Thank you for your comments. Unfortunately, the current evidence cannot assess the possibility that differences in data collection year, person-related characteristics, and university might influence the distance between inter-belongings. In addition, although the participants’ belongings were limited to bags in the previous study (Ariga, 2016), in the present study, we did not restrict participants to carry only bags. We agree with your comment that it is important to highlight this information when making claims about COVID-19-related changes in behavior. Thus, in the conclusion part, we added, “…the results show that people significantly increased, with a large effect size, the distance between personal belongings during the COVID-19 pandemic. It is important to note, however, that the results of the present experiment do not fully demonstrate that COVID-19 was the only factor that affected the expanded personal space between belongings.” As we stated in the Discussion section, our hypothesis was that the distance between objects to which the interpersonal relationship expands increased during the COVID-19 period, but we considered COVID-19 as just one possible reason for this. To avoid misunderstanding among readers and other researchers, we adjusted the tone of the descriptions related to the plausible explanations of our results in the Discussion section of the revised manuscript:" ... extended personal space increased during the period of COVID-19 pandemic, but we consider COVID-19 as one of the reasons for this change. " Reviewer Comment: “In my view, it would be much more convincing if the authors could show that distance is influenced by a subjective variable related to perceived vulnerability to Covid-19 (e.g. individual fear of an infection, belief about importance of social distancing as a policy against spread of infection, fear for family members,…, but also belief about whether belonging can be the source of infections) or an objective variable like cases reported in the news, number of active restrictions due to the pandemic, availability of vaccines. It seems also to be the case that standard deviations were bigger in the present study, suggesting a stronger influence of individual characteristics. Anyway, this point needs to be made more clearly throughout the manuscript and should even be reported in the abstract. Side note: Looking in the pre-registration the effect of the within-subject factor “alcohol disinfection” could be also informative about that.” Author Reply: Several studies related to personal distance during COVID-19, such as Fini et al. (2021), have shown that interpersonal distance is influenced by the perception of Realistic Threat, as measured through the COVID-19 threat. Moreover, previous research suggests that the public's practice of social distancing is not solely driven by the perception of infection but also by the social meaning of collective health (Fazio et al., 2021). We have added the following to the third paragraph of the introduction: “... which means that exposed people and objects may carry the coronavirus present in aerosols. Doremalen et al. (2020) compared the survivability of SARS-CoV-2 (leading to COVID-19) and SARS-CoV-1 on different surfaces. They found that the survival time of SARS-CoV-2 on various material surfaces ranged from a few hours to a few days, suggesting that the surface of an item can be a potential pathway for virus transmission. Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) have also mentioned that the virus can be transmitted through direct contact with contaminated surfaces.” We greatly appreciate your suggestion to include these previous research findings in the manuscript and the abstract. This will help clarify to readers that the increased distance between belongings during COVID-19 may be influenced by the perceived threat that objects can also be a source of infection. Regarding the “alcohol disinfection” condition, it belonged to another experiment in our lab. For this experiment, we can only provide the results, which indicate that expanded personal space does not change depending on hand disinfection. Reviewer Comment: “As a related point, it would be great to get more information on the state of the pandemic at the test center during the test period. How many new infections were reported during this time? What were the active policies against spread of infections, was the topic very present in the media? I ask this because in Germany, in the second half of 2022 the pandemic was less of a topic than in the years before and there were (almost) no impacts of Covid-19 related restriction in everyday life. I wonder whether similar claims could be made about Japan during this time?” Author Reply: We utilized Google Trends to track the frequency of the keyword "コロナ" (Japanese term for COVID-19) in Google searches. The data revealed that media coverage of COVID-19 in Japan fluctuated significantly, with the peak occurring at the onset of the pandemic in early 2020. Our experiment took place from June 2022 to January 2023, during which time the final wave of COVID-19 peaked, and media coverage remained high. However, by January 2023, media coverage started to decrease. Additionally, COVID-19-related information was widely disseminated not only through news and entertainment media but also in public places such as restaurants and shopping malls, where social distancing and health and safety measures were prominently displayed. According to Japanese news reports [Please refer to the below links for Image 1 and Image 2] , the number of new COVID-19 infections across Japan exceeded 40,000 per day starting in June 2022, reaching over 100,000 per day by July 2022. This marked the highest number of cases since the initial outbreak of COVID-19 in Japan in 2020. Image 1 Reference link: https://f1000research.s3.amazonaws.com/linked/669428.Image_1.pdf Image 2 Reference link: https://f1000research.s3.amazonaws.com/linked/669429.Image_2.pdf Reviewer Comment: “In addition, it would strengthen the argument of the authors to describe how the actual distance between persons was related to the distance between belongings. Was the distance in belonging correlated to actual distancing?” Author Reply: While we believe that our current findings reflect the physical distance between the confederate and the participant, we did not measure this distance during the actual experiment. Instead, we fixed their physical distance to eliminate any potential influence that physical distance might have had on the placement of objects, as it could have affected the results. Reviewer Comment: “Please also include more details on the paradigm here: How big was the distance between chairs in the experimental setting? Was it closer or further than a minimum recommended distance? Could this influence the placing of belongings?” Author Reply: The distance between the two chairs was approximately 30-40 cm, significantly less than the recommended social distancing measure of 2 meters due to the constraints of the experiment room's size and layout. The small distance between chairs may have created a sense of social anxiety and constriction at the beginning, making participants place belongings farther away to alleviate seated proximity in subsequent place sessions. No studies have been done to illustrate the effect of physical proximity on the unraveling of the distance between items. We added this part of the influence of chair distance on the distance of placing objects in the limitation part. "... as they were unsure whether the stranger and their belongings were infected with viruses. Moreover, some previous studies declared that the confined spaces may enhance the feeling of personal space invasion, thereby increasing psychological stress and anxiety (Aiello et al ., 1977; Evans, & Wener, 2007). In the present study, for strict replication and fair comparison, the chair distance was set to be the same as in the original experiment conducted in the pre-pandemic period, but the small distance between chairs may have created a sense of social anxiety and constriction at the beginning, making participants place belongings farther away to alleviate seated proximity in subsequent place sessions. No studies that have been done to illustrate the effect of physical proximity on the unraveling of the distance between items. "... and sat next to the confederate’s chair. The distance between two chairs was roughly 30-40 cm." in the Procedure section. Reviewer Comment: “The authors suggest that a ceiling effect precluded them from finding an effect of friendliness as in Ariga 2016. Looking at the distributions most of the distances were below 60 cm with the table being 150 cm wide (but please state where exactly on the table the belongings of the confederate where located), and original effect being around 10 cm. These data seem to suggest that the effect would have been observable if present. Another interpretation might therefore be that the belongings may not reflect personal space after all (contrary to Ariga, 2016). This should be discussed.” Author Reply: Thank you for your insightful comment. Our manuscript lacked a crucial piece of information: the size of the confederate's belongings, which is approximately 36 cm wide. We have now included this detail in our manuscript. Although the confederate experimenters tried to place their belongings as far as possible to the left corner of the desks, the space left for the participants was estimated to be around 100-110 cm. Additionally, the maximum distance between the belongings would be approximately 60 cm, assuming the participant's belongings were about 40 cm wide. Attempting to increase the distance by 10 cm from the unfriendly confederate's belongings to the average brings it close to the maximum possible distance. Participants might have avoided placing their belongings in the corners due to concerns about them falling. We believe that if the desks had been longer, participants could have placed their belongings further from the unfriendly confederate's belongings without the risk of them falling. Based on this context, we interpreted the results as being influenced by a ceiling effect. Your comment helped us identify and address this missing information. Reviewer Comment: Minor: “I suggest to change the wording “peacetime” to “pre-pandemic” throughout.” Author Reply: We changed it to “pre-pandemic”. Reviewer Comment: “I had difficulties understanding the first paragraph, maybe consider rephrasing it. Also there is more recent evidence on the relation of peripersonal space and interpersonal distance (e.g. see works of Yann Coello)” Author Reply: Thank you for your comments. We have rewritten the first paragraph and added new studies to help clarify our logic for you and the readers. “Social psychology and proxemics have long addressed personal space as the spatial range surrounding the individual (Sommer, 1959; Hall, 1966). The space around them represents a mediation zone between the body and the environment, contributing to the organization of social life. For example, when this space is encroached by others, we may feel uncomfortable or may prepare our bodies for defensive responses (Hall, 1966; Coello and Cartaud, 2021). However, the center of personal space is oneself, but it is not restricted to the physical body; much evidence proposed that the concept of self is expanding in space and timeline. For example, the ‘cutaneous rabbit’ can be felt not only on one’s body but also on an object that one is grasping (Miyazaki et al., 2010). The line of sight away from the eye can still be perceived as exerting force on the object (Guterstam et al., 2019). Furthermore, the extension of body representations to objects has been observed in neuroscience (Iriki et al., 1996). As a result, personal space boundaries also expand with the extension of body perception.” Competing Interests: No competing interests were disclosed. Close Report a concern COMMENT ON THIS REPORT Comments on this article Comments (0) Version 3 VERSION 3 PUBLISHED 20 Feb 2023 ADD YOUR COMMENT Comment keyboard_arrow_left keyboard_arrow_right Open Peer Review Reviewer Status info_outline Alongside their report, reviewers assign a status to the article: Approved The paper is scientifically sound in its current form and only minor, if any, improvements are suggested Approved with reservations A number of small changes, sometimes more significant revisions are required to address specific details and improve the papers academic merit. Not approved Fundamental flaws in the paper seriously undermine the findings and conclusions Reviewer Reports Invited Reviewers 1 2 3 4 Version 3 (revision) 05 Feb 25 read read read read Version 2 (revision) 27 Aug 24 read Version 1 20 Feb 23 read read Leon O. H Kroczek , University of Regensburg, Regensburg, Germany Tomoko Isomura , Nagoya University, Nagoya, Japan Nur Givon-Benjio , University of Haifa, Haifa, Israel Genta Miyazaki , Gakushuin University, Tokyo, Japan Comments on this article All Comments (0) Add a comment Sign up for content alerts Sign Up You are now signed up to receive this alert Browse by related subjects keyboard_arrow_left Back to all reports Reviewer Report 0 Views copyright © 2025 Isomura T. This is an open access peer review report distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 17 Feb 2025 | for Version 3 Tomoko Isomura , Graduate School of Informatics, Nagoya University, Nagoya, Japan 0 Views copyright © 2025 Isomura T. This is an open access peer review report distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. format_quote Cite this report speaker_notes Responses (1) Approved With Reservations info_outline Alongside their report, reviewers assign a status to the article: Approved The paper is scientifically sound in its current form and only minor, if any, improvements are suggested Approved with reservations A number of small changes, sometimes more significant revisions are required to address specific details and improve the papers academic merit. Not approved Fundamental flaws in the paper seriously undermine the findings and conclusions I sincerely apologize for my delayed response due to issues with receiving notifications. I appreciate the authors' efforts in addressing my concerns. One thing I am still wondering about is their raw data. While the authors mentioned that there are 68 data after excluding two participants who did not bring any belongings, I found that the raw data includes all 70 participants with "distance" data. What do the distance data from these two participants represent then? I have no further concerns beyond this. Competing Interests No competing interests were disclosed. Reviewer Expertise experimental psychology; embodied cognition; social cognition I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above. reply Respond to this report Responses (1) Author Response 10 Mar 2025 Kaito Takashima, Graduate School of Human-Environment Studies, Kyushu University, Fukuoka, Japan We apologize for not describing this clearly. Two participants did not bring any personal belongings with them, but they took our flyer at the reception desk and placed them on the table during the experiment, so we also measured the distance according to the experimental procedures. However, the flyer could not be counted as personal belongings. Therefore, even though we obtained these two participants’ data, we excluded the data of these two considering the definition of personal belongings in the experimental purpose. View more View less Competing Interests No competing interests were disclosed. reply Respond Report a concern Isomura T. Peer Review Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.177402.r364741) NOTE: it is important to ensure the information in square brackets after the title is included in this citation. The direct URL for this report is: https://f1000research.com/articles/12-199/v3#referee-response-364741 keyboard_arrow_left Back to all reports Reviewer Report 0 Views copyright © 2025 Miyazaki G. This is an open access peer review report distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 17 Feb 2025 | for Version 3 Genta Miyazaki , Gakushuin University, Tokyo, Japan 0 Views copyright © 2025 Miyazaki G. This is an open access peer review report distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. format_quote Cite this report speaker_notes Responses (0) Approved With Reservations info_outline Alongside their report, reviewers assign a status to the article: Approved The paper is scientifically sound in its current form and only minor, if any, improvements are suggested Approved with reservations A number of small changes, sometimes more significant revisions are required to address specific details and improve the papers academic merit. Not approved Fundamental flaws in the paper seriously undermine the findings and conclusions Summary: This pre-registered study examined whether individuals placed their personal belongings at a greater distance from others’ belongings during the COVID-19 pandemic than before. The authors compared experimental results from the COVID-19 pandemic with those from the pre-pandemic (Ariga, 2016). They found that personal belongings were spaced farther during the pandemic than before. The authors interpreted these findings as suggesting that as personal space expanded during the COVID-19 pandemic, the extended personal space, represented by the distance between belongings, also increased. Review: This study is valuable because it carefully replicates the experimental procedures of the previous research (Ariga, 2016 [Ref-1]). Furthermore, it provides crucial data on extended personal spaces during the COVID-19 pandemic. However, as the authors acknowledged in their discussion, the present study did not provide definitive evidence that the observed differences were caused directly by the COVID-19 pandemic. It may be helpful to analyze the responses to the question, "Why did you put the belongings there?" as measured in the present study, to address this limitation. How many participants indicated concerns about COVID-19 or adherence to social distancing? This analysis could help reinforce the interpretation of the authors’ findings. In a previous study (Ariga, 2016 [Ref-1]), responses to the same question were analyzed. This revealed that among the 20 participants in the unfriendly condition, 16 stated that they placed their bags away from the confederate’s bag because they did not want to put their belongings close to it. This suggests that the participants could verbalize their reasons for maintaining distance between their belongings and those of the confederate. Minor Points: The variance in the distance between belongings appeared to be greater during the pandemic than during the pre-pandemic period. Please provide an interpretation of this result. The manuscript states, "Intriguingly, our study did not find a significant effect of the confederate’s friendliness on participants’ behavior, as indicated by the lack of a significant interaction effect in the ANOVA" (p. 9). However, if the present experiment observed an effect of the confederate’s friendliness similar to that in Ariga (2016 [Ref-1]), an interaction should not have been expected. Instead of stating "the lack of a significant interaction effect," the sentence should refer to "the lack of a significant main effect of the confederate’s friendliness". Is the work clearly and accurately presented and does it cite the current literature? Yes Is the study design appropriate and is the work technically sound? Partly Are sufficient details of methods and analysis provided to allow replication by others? Yes If applicable, is the statistical analysis and its interpretation appropriate? Yes Are all the source data underlying the results available to ensure full reproducibility? Yes Are the conclusions drawn adequately supported by the results? Partly References 1. Ariga A: [Expansive personal space: Distance between personal belongings reflects the interpersonal distance of their owners]. Shinrigaku Kenkyu . 2016; 87 (2): 186-90 PubMed Abstract | Publisher Full Text Competing Interests No competing interests were disclosed. Reviewer Expertise social psychology; interpersonal relationships I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above. reply Respond to this report Responses (0) Miyazaki G. Peer Review Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.177402.r365484) NOTE: it is important to ensure the information in square brackets after the title is included in this citation. The direct URL for this report is: https://f1000research.com/articles/12-199/v3#referee-response-365484 keyboard_arrow_left Back to all reports Reviewer Report 0 Views copyright © 2025 Givon-Benjio N. This is an open access peer review report distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 12 Feb 2025 | for Version 3 Nur Givon-Benjio , University of Haifa, Haifa, Israel 0 Views copyright © 2025 Givon-Benjio N. This is an open access peer review report distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. format_quote Cite this report speaker_notes Responses (0) Approved info_outline Alongside their report, reviewers assign a status to the article: Approved The paper is scientifically sound in its current form and only minor, if any, improvements are suggested Approved with reservations A number of small changes, sometimes more significant revisions are required to address specific details and improve the papers academic merit. Not approved Fundamental flaws in the paper seriously undermine the findings and conclusions The authors have thoroughly addressed all of my concerns. Competing Interests No competing interests were disclosed. Reviewer Expertise Interpersonal distance (preference, perception) in COVID-19 as well as in clinical populations (social anxiety, autism). I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard. reply Respond to this report Responses (0) Givon-Benjio N. Peer Review Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.177402.r364740) NOTE: it is important to ensure the information in square brackets after the title is included in this citation. The direct URL for this report is: https://f1000research.com/articles/12-199/v3#referee-response-364740 keyboard_arrow_left Back to all reports Reviewer Report 0 Views copyright © 2025 Kroczek L. This is an open access peer review report distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 12 Feb 2025 | for Version 3 Leon O. H Kroczek , University of Regensburg, Regensburg, Germany 0 Views copyright © 2025 Kroczek L. This is an open access peer review report distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. format_quote Cite this report speaker_notes Responses (0) Approved info_outline Alongside their report, reviewers assign a status to the article: Approved The paper is scientifically sound in its current form and only minor, if any, improvements are suggested Approved with reservations A number of small changes, sometimes more significant revisions are required to address specific details and improve the papers academic merit. Not approved Fundamental flaws in the paper seriously undermine the findings and conclusions The authors have responded to all of my comments. This includes more details with respect to the experimental setting and a more nuanced discussion of the results with respect to other factors which might have driven the effect. Competing Interests No competing interests were disclosed. Reviewer Expertise interpersonal distance, socio-affective behavior I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard. reply Respond to this report Responses (0) Kroczek LOH. Peer Review Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.177402.r364739) NOTE: it is important to ensure the information in square brackets after the title is included in this citation. The direct URL for this report is: https://f1000research.com/articles/12-199/v3#referee-response-364739 keyboard_arrow_left Back to all reports Reviewer Report 0 Views copyright © 2025 Givon-Benjio N. This is an open access peer review report distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 31 Dec 2024 | for Version 2 Nur Givon-Benjio , University of Haifa, Haifa, Israel 0 Views copyright © 2025 Givon-Benjio N. This is an open access peer review report distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. format_quote Cite this report speaker_notes Responses (1) Approved With Reservations info_outline Alongside their report, reviewers assign a status to the article: Approved The paper is scientifically sound in its current form and only minor, if any, improvements are suggested Approved with reservations A number of small changes, sometimes more significant revisions are required to address specific details and improve the papers academic merit. Not approved Fundamental flaws in the paper seriously undermine the findings and conclusions The current study examined changes in the distance at which people placed their belongings before and after the COVID-19 outbreak in Japan. The authors employed an ecological task simulating a real-life scenario. The results suggest that the pandemic predicted an enlargement (or expansion) of the distance people placed their belongings from those of a confederate. This effect was not explained by whether the confederate was friendly or hostile, nor by a time*confederate interaction. Overall, I found the study very interesting and with the potential to make a meaningful contribution to existing knowledge. However, there are several areas that warrant further clarification and consideration: 1. A clear distinction should be made between interpersonal distance, which refers to the space between people (as discussed by Hall), and peripersonal distance, the space immediately surrounding the body within reach (as explored by Coello and Cartaud). This differentiation is critical for framing the study's context. The fear of infection during the COVID-19 pandemic is primarily linked to interpersonal distance. Studies have shown that fear of infection correlates with a preference for greater interpersonal distance and an underestimation of interpersonal space. However, these effects are tied to subjective perceptions of risk rather than objective risk of infection (Givon-Benjio et al., 2024). On the other hand, personal belongings conceptually align more with peripersonal distance. For example, Lenglart et al. (2023) demonstrated that personal items are perceived as more "within reach" compared to other objects, indicating an expansion of peripersonal distance representation. The paper by Coello and Cartaud (2021), cited in the introduction, suggests that interpersonal and peripersonal distances are interlinked and together influence social behavior. I recommend moving this discussion to the end of the paragraph, after clarifying the distinction between the two concepts. Additionally, the innovative nature of this study should be explicitly mentioned—specifically, its combination of these two concepts, typically studied independently, to provide novel insights into how they are interconnected. This distinction and integration should also be revisited in the discussion section. Existing literature suggests that the perception of distance is highly context-dependent. For example, would the effect still emerge when the perceived risk is low? Would it manifest if participants were asked to place items they do not own? Or, on the other hand, could the effect persist, as suggested by the lack of influence of the confederate manipulation on the results? Addressing these contextual factors could be done as suggestions for future studies, as answering them may lead to different theoretical and practical conclusions. Lenglart, L., Cartaud, A., Quesque, F., Sampaio, A., & Coello, Y. (2023 [Ref - 1]). Object coding in peripersonal space depends on object ownership. Quarterly Journal of Experimental Psychology, 76(8), 1925-1939. Givon-Benjio, N., Sokolover, H., Aderka, I. M., Hadad, B. S., & Okon-Singer, H. (2024 [Ref -2]). Perception of interpersonal distance and social distancing before and during COVID-19 pandemic. Scientific Reports, 14(1), 4568. 2. If the authors use the term "personal space" to refer specifically to peripersonal distance, they should explicitly adopt this terminology throughout the manuscript and to update the literature review, especially after the first paragraph. Alternatively, if "personal space" is intended to mean something different from the space surrounding the body, they should clearly define the term. 3. The discussion on interpersonal distance (IPD) during COVID-19 in the introduction is incomplete. While the authors cite studies demonstrating an enlargement of IPD following the pandemic, the paragraph overlooks important nuances. For instance, Iachini et al. (2021), which is already cited, found that the increase in IPD occurred only when subjective risk was high. Similarly, Givon-Benjio et al. (2024) compared data from before and after the outbreak and observed that subjective risk, rather than actual risk (e.g., infection rate), predicted changes in preferred interpersonal distance. Even when the actual risk was high, preferred interpersonal distance remained unchanged. These findings are further supported Cartaud et al., 2020). The introduction should reflect that the enlargement of IPD is not a universal or conclusive effect but is highly dependent on subjective risk levels. While the authors touch on subjective risk in the discussion, particularly when discussing perceived vulnerability to disease (PVD), this concept should receive greater emphasis both in the introduction and discussion to provide a more nuanced understanding of the findings. Cartaud, A., Quesque, F. & Coello, Y. Wearing a face mask against Covid-19 results in a reduction of social distancing. Plos One 15(12), e0243023 (2020 [Ref-3]). 4. Supporting the findings is a study that found that COVID-19 is linked to reduction in peripersonal distance, which can help explain why people want to put their belonging further away. Serino, S. et al. Sharpening of peripersonal space during the COVID-19 pandemic. Curr. Biol. 31(14), R889–R890 (2021 [Ref - 4]). 5. The fact that participants wore face masks should be mentioned earlier in the text, specifically in the Methods section, as it is a relevant procedural detail. Additionally, this should be discussed further in the Discussion section, with reference to studies examining the relationship between mask-wearing and interpersonal or peripersonal distance. Minor: 6.I found the observations about the role of smartphones and their potential impact on personal space particularly insightful in the discussion. 7. I suggest reconsidering the inclusion of Figure 3, as it primarily displays the results of a manipulation check, and may not add value to the main narrative of the paper. Is the work clearly and accurately presented and does it cite the current literature? Partly Is the study design appropriate and is the work technically sound? Yes Are sufficient details of methods and analysis provided to allow replication by others? Partly If applicable, is the statistical analysis and its interpretation appropriate? Yes Are all the source data underlying the results available to ensure full reproducibility? No source data required Are the conclusions drawn adequately supported by the results? Partly References 1. Lenglart L, Cartaud A, Quesque F, Sampaio A, et al.: Object coding in peripersonal space depends on object ownership. Q J Exp Psychol (Hove) . 2023; 76 (8): 1925-1939 PubMed Abstract | Publisher Full Text 2. Givon-Benjio N, Sokolover H, Aderka IM, Hadad BS, et al.: Perception of interpersonal distance and social distancing before and during COVID-19 pandemic. Sci Rep . 2024; 14 (1): 4568 PubMed Abstract | Publisher Full Text 3. Cartaud A, Quesque F, Coello Y: Wearing a face mask against Covid-19 results in a reduction of social distancing. PLoS One . 2020; 15 (12): e0243023 PubMed Abstract | Publisher Full Text 4. Serino S, Trabanelli S, Jandus C, Fellrath J, et al.: Sharpening of peripersonal space during the COVID-19 pandemic. Curr Biol . 2021; 31 (14): R889-R890 PubMed Abstract | Publisher Full Text Competing Interests No competing interests were disclosed. Reviewer Expertise Interpersonal distance (preference, perception) in COVID-19 as well as in clinical populations (social anxiety, autism). I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above. reply Respond to this report Responses (1) Author Response 05 Feb 2025 Kaito Takashima, Graduate School of Human-Environment Studies, Kyushu University, Fukuoka, Japan The current study examined changes in the distance at which people placed their belongings before and after the COVID-19 outbreak in Japan. The authors employed an ecological task simulating a real-life scenario. The results suggest that the pandemic predicted an enlargement (or expansion) of the distance people placed their belongings from those of a confederate. This effect was not explained by whether the confederate was friendly or hostile, nor by a time*confederate interaction. Overall, I found the study very interesting and with the potential to make a meaningful contribution to existing knowledge. However, there are several areas that warrant further clarification and consideration: 1. A clear distinction should be made between interpersonal distance, which refers to the space between people (as discussed by Hall), and peripersonal distance, the space immediately surrounding the body within reach (as explored by Coello and Cartaud). This differentiation is critical for framing the study's context. The fear of infection during the COVID-19 pandemic is primarily linked to interpersonal distance. Studies have shown that fear of infection correlates with a preference for greater interpersonal distance and an underestimation of interpersonal space. However, these effects are tied to subjective perceptions of risk rather than objective risk of infection (Givon-Benjio et al., 2024). On the other hand, personal belongings conceptually align more with peripersonal distance. For example, Lenglart et al. (2023) demonstrated that personal items are perceived as more "within reach" compared to other objects, indicating an expansion of peripersonal distance representation. The paper by Coello and Cartaud (2021), cited in the introduction, suggests that interpersonal and peripersonal distances are interlinked and together influence social behavior. I recommend moving this discussion to the end of the paragraph, after clarifying the distinction between the two concepts. Additionally, the innovative nature of this study should be explicitly mentioned—specifically, its combination of these two concepts, typically studied independently, to provide novel insights into how they are interconnected. This distinction and integration should also be revisited in the discussion section. Existing literature suggests that the perception of distance is highly context-dependent. For example, would the effect still emerge when the perceived risk is low? Would it manifest if participants were asked to place items they do not own? Or, on the other hand, could the effect persist, as suggested by the lack of influence of the confederate manipulation on the results? Addressing these contextual factors could be done as suggestions for future studies, as answering them may lead to different theoretical and practical conclusions. Lenglart, L., Cartaud, A., Quesque, F., Sampaio, A., & Coello, Y. (2023 [Ref - 1]). Object coding in peripersonal space depends on object ownership. Quarterly Journal of Experimental Psychology, 76(8), 1925-1939. Givon-Benjio, N., Sokolover, H., Aderka, I. M., Hadad, B. S., & Okon-Singer, H. (2024 [Ref -2]). Perception of interpersonal distance and social distancing before and during COVID-19 pandemic. Scientific Reports, 14(1), 4568. Response: Thank you for acknowledging the innovative aspects of our study, and highlighting the importance of clearly distinguishing between interpersonal distance (IPD) and peripersonal distance (PPD). Following your suggestion, we have made the following revisions. Firstly, in the first paragraph of introduction, we clearly define and describe interpersonal space and peripersonal space. Then, at the end of the introduction, the innovation point of this paper is added, that is, it combines these two concepts for the first time and discusses their influence on social behavior. Finally,we expanded the discussion on future research direction by incorporating new questions based on your suggestions to highlight how contextual factors may influence our findings.These additions provide a stronger foundation for future studies investigating how interpersonal and peripersonal space interact under different conditions. We sincerely appreciate your constructive feedback, as it has significantly enhanced the theoretical clarity and coherence of our manuscript. Revised version: use underline__ …Social psychology and proxemics have long addressed personal space as the spatial range surrounding the individual (Sommer, 1959; Hall, 1966). The space around the individual may exist in two forms. One is interpersonal distance, the area around the body that individuals maintain between themselves and others during social interactions (Candini et al., 2021). The other one is peripersonal space, which is an adaptive and flexible interface between the body and the environment The space around them represents a mediation zone between the body and the environment, contributing to the organization of social life. For example, when this space is encroached by others, we may feel uncomfortable or may prepare our bodies for defensive responses (Hall, 1966; Coello and Cartaud, 2021). ……… …How has the COVID-19 pandemic and countermeasures against it changed human-human and human-object interactions? Considering the findings of Ariga (2016), one’s personal space extends to his/her belongings, leaving them with an ‘extended personal space’. The present study aimed to examine if the ‘extended personal space’ increased as well as the personal space that has been affected under the pandemic of COVID-19. The fear of infection during the COVID-19 pandemic is closely associated with interpersonal distance. Research indicates that this fear is linked to a tendency to prefer greater interpersonal distance and to underestimate interpersonal space. However, these tendencies stem from subjective perceptions of risk rather than an actual objective risk of infection (Givon-Benjio et al., 2024). On the other hand, personal belongings are more closely related to peripersonal distance. For instance, Lenglart et al. (2023) found that individuals perceive personal items as being more "within reach" compared to other objects, suggesting an expansion in the representation of peripersonal distance. Based on the Coello and Cartaud, they indicated that interpersonal and peripersonal distances are interlinked and together influence social behavior. Therefore, in this study, we innovatively combine these two concepts for the first time to explore the impact of the combination of these two forms of personal space on social actions. Discussion: To dissociate the factor of the pandemic from other potential factors, conducting the study using the same procedure again after the pandemic would be effective. Additionally, future studies should further examine how interpersonal and peripersonal distances interact in different contexts. For example, the level of perceived infectability (i.e., beliefs about one’s own susceptibility to infectious diseases) in 2023 has dropped to the same level as before the COVID-19 pandemic in Japan (Ikeda et al., 2024). Although the number of diagnosed COVID-19 cases remains high, people's subjective risk perception has declined. The potential changes in sensitivity suggested by such reports provide us with numerous possibilities for discussion. Would the effect still emerge when the perceived risk of infection is low? Additionally, would it manifest if participants were asked to place items they do not own? Alternatively, the persistence of the effect—despite the lack of influence of the confederate’s friendliness—suggests that the expansion of peripersonal space during the pandemic might be independent of social cues. Furthermore, the perception of distance may be shaped by long-term societal and technological changes. The widespread use of smartphones and social media in the 2010s might have altered norms around physical proximity and social interaction. Future research could investigate whether personal space norms adapt to such technological shifts and how these changes interact with interpersonal and peripersonal distances. Added references: Candini, M., Battaglia, S., Benassi, M., di Pellegrino, G., & Frassinetti, F. (2021). The physiological correlates of interpersonal space. Scientific Reports , 11 (1), 2611. https://doi.org/10.1038/s41598-021-82223-2 Lenglart, L., Cartaud, A., Quesque, F., Sampaio, A., & Coello, Y. (2023). Object coding in peripersonal space depends on object ownership. Quarterly Journal of Experimental Psychology , 76 (8), 1925-1939. https://doi.org/10.1177/17470218221128306 Givon-Benjio, N., Sokolover, H., Aderka, I. M., Hadad, B. S., & Okon-Singer, H. (2024). Perception of interpersonal distance and social distancing before and during COVID-19 pandemic. Scientific Reports , 14 (1), 4568. https://doi.org/10.1038/s41598-024-55218-y Ikeda A, Sasaki K, Yamada Y.: Evolution of perceived vulnerability to infection in Japan during the COVID-19 pandemic. Qeios. 2024. https://doi.org/10.32388/4CO88Y.4 2. If the authors use the term "personal space" to refer specifically to peripersonal distance, they should explicitly adopt this terminology throughout the manuscript and to update the literature review, especially after the first paragraph. Alternatively, if "personal space" is intended to mean something different from the space surrounding the body, they should clearly define the term. Response： Thank you for confirming the uniformity of terms. In the present study, "personal space" refers to the surrounding space centered on one's body that is not invaded by others in social activities. Closer to the concept of peripersonal space. In addition, the personal space extended by personal belongings is also closer to the "peripersonal space". We clarified the definition of peripersonal space in the first paragraph of introduction and the reference to personal space in our manuscript to ensure the clear and consistent use of terms. Revised version: Social psychology and proxemics have long addressed personal space as the spatial range surrounding the individual ( Sommer, 1959; Hall, 1966). The space around the individual may exist in two forms. One is interpersonal distance, the area around the body that individuals maintain between themselves and others during social interactions (Candini et al., 2021). The other one is peripersonal space, which is an adaptive and flexible interface between the body and the environment, contributing to the organization of social life. For example, when this space is encroached by others, we may feel uncomfortable or may prepare our bodies for defensive responses ( Hall, 1966; Coello and Cartaud, 2021) . In our study, the concept of 'personal space,' as referenced later, aligns more closely with the notion of peripersonal space. This refers to the space immediately surrounding the body, within reach, centered on the individual, and typically protected from intrusion during social interactions. One observed phenomenon is in some school situations where there are desk-mates; after an argument, desk-mates will avoid putting their stationery close to the other’s belongings. It is possible that people develop a tendency to recognize personal belonging as a representation of the self at an early age ( Pedersen, 1973). According to James (1890), the self is the sum of all that he can call his, including all possessions, which gives him the same emotions. Briefly, we regard our possessions as part of ourselves. This intrinsic association between personal belongings and the self-forms the foundation for understanding how external objects, including tools and technologies, can become integrated into one’s sense of self, extending the boundaries of personal space. Studies on body ownership illusions suggest that the integration of external objects or virtual representations into one’s sense of self occurs through multisensory signals, highlighting the neural mechanisms underlying extended personal space (Nilsson & Kalckert, 2021). Is this sense of ownership of objects related to personal space? Ariga (2016) reported that participants placed their own objects at a greater distance from the objects of those who were unfavorable. These findings suggest that individuals’ personal space extended to the space surrounding their belongings (i.e., extended personal space). The placement of such personal belongings can be considered the most significant evidence of an extension of personal space, as it shares the same characteristics with personal space ( Russell & Ward, 1982; Becker, 1973), that the variability depending on the level of familiarity with others. Moreover, recent studies have shown that object ownership influences the representation of peripersonal space. Specifically, self-owned objects within the peripersonal space are processed faster and perceived as more reachable compared to objects owned by others, suggesting an extension of peripersonal space representation around self belongings (Lenglart et al., 2023). This effect is particularly pronounced in individuals with higher interpersonal sensitivity, as their peripersonal space boundaries dynamically adapt in response to social contexts. Further supporting this perspective, Rabellino et al. (2020) highlight that peripersonal space is not only critical for physical interactions with the environment but also closely tied to bodily self-consciousness. They suggest that peripersonal space representation involves multisensory processing and serves both protective and social functions, allowing individuals to dynamically adjust to interactions with others. These findings further support the idea that ownership can extend personal space to include the area surrounding one's possessions, reinforcing the concept of "extended personal space." Added references Lenglart, L., Cartaud, A., Quesque, F., Sampaio, A., & Coello, Y. (2023). Object coding in peripersonal space depends on object ownership. Quarterly Journal of Experimental Psychology , 76 (8), 1925-1939. https://doi.org/10.1177/17470218221128306 Nilsson, M., & Kalckert, A. (2021). Region‐of‐interest analysis approaches in neuroimaging studies of body ownership: An activation likelihood estimation meta‐analysis. European Journal of Neuroscience , 54 (11), 7974-7988. https://doi.org/10.1111/ejn.15534 Rabellino, D., Frewen, P. A., McKinnon, M. C., & Lanius, R. A. (2020). Peripersonal space and bodily self-consciousness: implications for psychological trauma-related disorders. Frontiers in Neuroscience , 14 , 586605. https://doi.org/10.3389/fnins.2020.586605 3. The discussion on interpersonal distance (IPD) during COVID-19 in the introduction is incomplete. While the authors cite studies demonstrating an enlargement of IPD following the pandemic, the paragraph overlooks important nuances. For instance, Iachini et al. (2021), which is already cited, found that the increase in IPD occurred only when subjective risk was high. Similarly, Givon-Benjio et al. (2024) compared data from before and after the outbreak and observed that subjective risk, rather than actual risk (e.g., infection rate), predicted changes in preferred interpersonal distance. Even when the actual risk was high, preferred interpersonal distance remained unchanged. These findings are further supported Cartaud et al., 2020). The introduction should reflect that the enlargement of IPD is not a universal or conclusive effect but is highly dependent on subjective risk levels. While the authors touch on subjective risk in the discussion, particularly when discussing perceived vulnerability to disease (PVD), this concept should receive greater emphasis both in the introduction and discussion to provide a more nuanced understanding of the findings. Cartaud, A., Quesque, F. & Coello, Y. Wearing a face mask against Covid-19 results in a reduction of social distancing. Plos One 15(12), e0243023 (2020 [Ref-3]). Response: We appreciate your insightful comments on the nuanced relationship between interpersonal distance and subjective risk during the COVID-19 pandemic. In response, we have revised the introduction to provide a more balanced discussion on the enlargement of interpersonal distance, emphasizing that this phenomenon is highly dependent on subjective risk levels rather than being a universal or conclusive effect. Specifically, we have incorporated findings from Iachini et al. (2021), Givon-Benjio et al. (2024), and Cartaud et al. (2020) to illustrate how subjective risk plays a crucial role in modulating interpersonal distance. Furthermore, we have strengthened the connection between subjective risk and the concept of extended personal space in the discussion part, which forms the core focus of our study. For details revise, please see "Revised version" Revised version: …Recent studies have reported that interpersonal distance (IPD) increased during the COVID-19 pandemic ( Holt et al. , 2022; Iachini et al. , 2021), and enlarged IPD preferences were predicted to persist beyond the pandemic ( Welsch et al., 2021). However, it is important to note that the enlargement of IPD is not a universal phenomenon. As Iachini et al. (2021) observed, IPD increases only when subjective risk levels are high. Similarly, Givon-Benjio et al. (2024) demonstrated that subjective risk, rather than actual infection risk, predicted changes in preferred IPD. Cartaud et al. (2020) further supported this by showing that even under conditions of high actual risk, individuals’ preferred IPD remained unchanged unless subjective risk was elevated. The results of an experiment in Arabia revealed that in the post-epidemic era, 76% of the participants were already subjectively reluctant to share close physical distance or socially polite touch with others ( Khan et al., 2021). Responding to precautions, the external manifestation is that we have actively increased our physical distance, but in reality, personal space has also expanded accordingly. In several studies related to personal distance in COVID-19, Fini et al. (2021)showed that interpersonal distance is influenced by the perception of realistic threat measured through the COVID-19 threat. In addition, previous research proposed that not only the perception of infection will make the public practice social distancing, but the behavior of practicing social distancing is related to specific individuals as well as related to the social meaning of collective health ( Fazio et al ., 2021). Discussion : Since personal belongings also can be the source of infection through aerosols, the perceived risk of infection may extend to them. It is precisely due to the increased subjective perception of risk that, in the context of COVID-19, the extension of personal belongings comes to represent the characteristics of personal space, and the distance between personal belongings also increases. Participants without sufficient prior information could place their belongings at a distance from the confederate’s belongings to avoid contamination as they were unsure whether the stranger and their belongings were infected with viruses. 4. Supporting the findings is a study that found that COVID-19 is linked to reduction in peripersonal distance, which can help explain why people want to put their belonging further away. Serino, S. et al. Sharpening of peripersonal space during the COVID-19 pandemic. Curr. Biol. 31(14), R889–R890 (2021 [Ref - 4]). Response: Thank you for pointing out this relevant study by Serino et al. (2021). We agree that their findings on the sharpening of peripersonal space during the COVID-19 pandemic provide valuable support for our study. We have incorporated this reference into the discussion section to further explain the increased distance observed between personal belongings. Specifically, we added the following paragraph as in the "Revised version". Revised Version: Several studies have confirmed the increase in personal space during the COVID-19 pandemic and suggested the practice of social distancing attributed to the increase (Fini, Tummolini, and Borghi, 2021; Fazio et al., 2021). Moreover, our study found that the distance between objects increased during the pandemic. Recent findings from studies on the psychological impact of the COVID-19 pandemic provide additional support for our findings. For example, Serino et al. (2021) demonstrated that the pandemic led to a sharpening of peripersonal space boundaries, with individuals adapting their spatial perceptions in response to increased health-related concerns. This phenomenon aligns with our observation that the distance between personal belongings increased during the pandemic. The findings suggest that participants might have subconsciously extended their spatial boundaries to maintain greater safety and reduce perceived risks associated with potential contamination. This adaptation, as highlighted by Serino et al. (2021), may explain why people positioned their belongings farther away from other's during the pandemic. Considering Ariga (2016), personal belongings have the same personal space-like properties as the owner, belongings also maintain their social distance when they are placed. This distance could manifest in the elongated distance of personal belongings. 5. The fact that participants wore face masks should be mentioned earlier in the text, specifically in the Methods section, as it is a relevant procedural detail. Additionally, this should be discussed further in the Discussion section, with reference to studies examining the relationship between mask-wearing and interpersonal or peripersonal distance. Response: We revised the Methods section to include this procedural detail. Additionally, we expanded the Discussion section to explore the potential influence of mask-wearing on interpersonal and peripersonal distance, supported by Cartaud et al.(2020). Revised version: Methods The inclusion criteria were native Japanese or international students who could speak Japanese proficiently. They were paid 1000 yen to agree to participate. All participants were required to wear face masks throughout the experiment as part of standard COVID-19 precautions. Discussion In fact, all valid participants in this study voluntarily wore face masks, which is a routine infection control measure. Beyond compliance, mask-wearing might have also influenced the observed spatial distancing behavior. Research has shown that wearing face masks can alter interpersonal perceptions and decrease interpersonal and peripersonal distances in certain contexts. For example, Cartaud et al. (2020) found that individuals perceived as wearing face masks are considered more trustworthy, leading to reduced physical distance. Similarly, Biggio et al. (2022) reported that mask-wearing shapes interpersonal space by fostering a sense of safety and reducing the need for extended spatial boundaries. In our study, while participants wore face masks during the experiment, the observed increase in distance between personal belongings suggests that compliance with infection control measures and risk-avoidance behaviors might interact differently when participants place objects instead of interacting directly with people. Minor: 6.I found the observations about the role of smartphones and their potential impact on personal space particularly insightful in the discussion. Response: Thank you for your feedback. Our manuscript mentions that smartphones and social media may affect interpersonal distance, but not in conjunction with the concept of interpersonal/intimate distance. To that end, we modified and expanded the section (the modifications here partly same as the response to the question 1, but we're still showing it to you here) : Revised Version: Furthermore, the perception of distance may be shaped by long-term societal and technological changes. The widespread use of smartphones and social media in the 2010s might have altered norms around physical proximity and social interaction. Future research could investigate whether personal space norms adapt to such technological shifts and how these changes interact with interpersonal and peripersonal distances. 7. I suggest reconsidering the inclusion of Figure 3, as it primarily displays the results of a manipulation check, and may not add value to the main narrative of the paper. Reponse: Thank you for your comments. Figure 3 includes part of the results described in the text but also provides a visualization of the data distribution for the manipulation check. To streamline the manuscript, we removed Figure 3 while retaining the textual description, as we believe that the results of the manipulation check are crucial for demonstrating the validity of our experiment design. Revised version: …we calculated the mean favorability for each condition (friendly and unfriendly). View more View less Competing Interests No competing interests were disclosed. reply Respond Report a concern Givon-Benjio N. Peer Review Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.170298.r348889) NOTE: it is important to ensure the information in square brackets after the title is included in this citation. The direct URL for this report is: https://f1000research.com/articles/12-199/v2#referee-response-348889 keyboard_arrow_left Back to all reports Reviewer Report 0 Views copyright © 2024 Isomura T. This is an open access peer review report distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 14 May 2024 | for Version 1 Tomoko Isomura , Graduate School of Informatics, Nagoya University, Nagoya, Japan 0 Views copyright © 2024 Isomura T. This is an open access peer review report distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. format_quote Cite this report speaker_notes Responses (1) Approved With Reservations info_outline Alongside their report, reviewers assign a status to the article: Approved The paper is scientifically sound in its current form and only minor, if any, improvements are suggested Approved with reservations A number of small changes, sometimes more significant revisions are required to address specific details and improve the papers academic merit. Not approved Fundamental flaws in the paper seriously undermine the findings and conclusions Summary: This pre-registered study aimed to examine the effect of the COVID-19 pandemic on human behavior, specifically how long people prefer to keep their personal belongings distanced from others. The authors set up a scenario in which participants placed their personal belongings on a desk after a confederate had done the same, without being aware of the study's purpose. They measured the physical distance between the belongings of the participant and the confederate. The obtained data were compared with those from a previous study (Ariga, 2016), conducted before the pandemic using identical procedures. The results showed that the distance between belongings in the present study was greater than reported in the previous study. The authors concluded that the pandemic has increased the personal space people maintain, which further extends the distance they keep from others' belongings. Additionally, although the authors manipulated the confederate’s friendliness—a factor that the previous study demonstrated had an effect—this manipulation did not induce any differences in the present study. I found this study interesting, particularly in that the methods they employed were well-designed to capture human’s implicit attitude for the boundaries of self and others. The manuscript is generally well written, and it is valuable that the authors pre-registered this study. However, I have some concerns about this manuscript in its current form, as follows. Firstly, I question whether the terms "extended" or "extension of" personal space accurately represent the phenomenon described. I acknowledge that our representation of the bodily self can be modulated when manipulating objects or interacting with others, potentially resulting in an "extension," enlargement, or prolongation—or even the opposite—of one's peri-personal or personal space. However, the mental attitude of keeping one's belongings separate from others', especially when the objects are placed away from the body (e.g., on a desk when temporarily leaving), does not seem to me to constitute an "extension" of personal space, although I agree that it reflects some processing of self-other boundaries. It would be advantageous if the authors could include additional literature to support this concept, beyond Ariga (2016). On a related but more minor point, the authors state in the second paragraph of the Introduction that Sasaki et al., 2018 demonstrated that a sense of body ownership is conferred to objects. However, I believe that this study is more appropriately interpreted as showing that the sense of "object ownership" is driven by body-related processing, and the authors' interpretation may be somewhat misleading. Secondly, and more importantly, I found it highly challenging to assert that the effect observed by the authors is truly driven by the COVID-19 pandemic, given the limited measures they collected. While I acknowledge the inherent challenges in proving such causation, I suggest that the authors provide more information and/or conduct additional analyses to make the study more persuasive. Firstly, the authors should clearly state the size of the table and the position of the chair, ensuring they are indeed identical to those used in Ariga (2016). The authors should include this information in the main text, not just within a figure. I assume that the relative position of the chairs to the table would affect the participant’s behavior, as people tend to place objects directly in front of where they are seated. Thus, it is essential that these parameters were controlled between the studies. I also suggest the authors provide more information about the confederates, including their sexes and ages, because Ariga (2016) demonstrated that the relationship between the confederates' and participants' sexes had a clear effect on the results. Furthermore, I speculate that the size or number of the participants' belongings could affect the distance measures. It seems that Ariga (2016) considered only the participant’s bag, but what was the case in this study? If the authors have pictures of the placement of the belongings, they might be able to conduct additional analyses that could potentially rule out the influence of the size/number of the participant’s belongings on the findings. Ideally, it would have been valuable if the authors had collected some subjective scales related to the pandemic, such as how afraid the participants were of or how cautious they were about the infection. This could be a subject to consider for future studies. Minor points: In the third paragraph of the Introduction, the authors reference Tootell et al., 2021, as a study that reported an increase in interpersonal distance during the pandemic. However, I believe that this study was conducted before the pandemic. Could it be that the authors intended to cite Holt et al., 2022 instead? The authors should clearly specify the timing of data collection within the Methods section of the main text. Upon reviewing the raw data provided by the authors, I noticed that it includes 70 data. If I understood correctly, there should only be 68 data since 2 participants did not bring any belongings. Please check this. This study did not find any effect of the confederate's friendliness on the participants' behavior. The authors claims that this result is inconsistent with findings from Ariga (2006), potentially due to a ceiling effect. However, since the ANOVA revealed only a main effect of experimental timing and the interaction was not significant, it may be misleading to definitively state that the findings are inconsistent regarding the effect of the confederate's friendliness. Is the work clearly and accurately presented and does it cite the current literature? Yes Is the study design appropriate and is the work technically sound? Partly Are sufficient details of methods and analysis provided to allow replication by others? Partly If applicable, is the statistical analysis and its interpretation appropriate? Partly Are all the source data underlying the results available to ensure full reproducibility? Partly Are the conclusions drawn adequately supported by the results? Partly Competing Interests No competing interests were disclosed. Reviewer Expertise experimental psychology; embodied cognition; social cognition I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above. reply Respond to this report Responses (1) Author Response 27 Aug 2024 Kaito Takashima, Graduate School of Human-Environment Studies, Kyushu University, Fukuoka, Japan Replies to the comments by Dr.Tomoko Isomura (Graduate School of Informatics, Nagoya University, Nagoya, Japan): Reviewer Comments: “This pre-registered study aimed to examine the effect of the COVID-19 pandemic on human behavior, specifically how long people prefer to keep their personal belongings distanced from others. The authors set up a scenario in which participants placed their personal belongings on a desk after a confederate had done the same, without being aware of the study's purpose. They measured the physical distance between the belongings of the participant and the confederate. The obtained data were compared with those from a previous study (Ariga, 2016), conducted before the pandemic using identical procedures. The results showed that the distance between belongings in the present study was greater than reported in the previous study. The authors concluded that the pandemic has increased the personal space people maintain, which further extends the distance they keep from others' belongings. Additionally, although the authors manipulated the confederate’s friendliness—a factor that the previous study demonstrated had an effect—this manipulation did not induce any differences in the present study. I found this study interesting, particularly in that the methods they employed were well-designed to capture human’s implicit attitude for the boundaries of self and others. The manuscript is generally well written, and it is valuable that the authors pre-registered this study. However, I have some concerns about this manuscript in its current form, as follows.” “Firstly, I question whether the terms "extended" or "extension of" personal space accurately represent the phenomenon described. I acknowledge that our representation of the bodily self can be modulated when manipulating objects or interacting with others, potentially resulting in an "extension," enlargement, or prolongation—or even the opposite—of one's peri-personal or personal space. However, the mental attitude of keeping one's belongings separate from others', especially when the objects are placed away from the body (e.g., on a desk when temporarily leaving), does not seem to me to constitute an "extension" of personal space, although I agree that it reflects some processing of self-other boundaries. It would be advantageous if the authors could include additional literature to support this concept, beyond Ariga (2016). On a related but more minor point, the authors state in the second paragraph of the Introduction that Sasaki et al., 2018 demonstrated that a sense of body ownership is conferred to objects. However, I believe that this study is more appropriately interpreted as showing that the sense of "object ownership" is driven by body-related processing, and the authors' interpretation may be somewhat misleading.” Author Reply: Thank you very much for your insightful comments. Before starting this study, we extensively debated the differences between the sense of ownership and personal space and territory, ultimately concluding that this phenomenon is related to personal space. Here, we outline our rationale: The most significant evidence that the extended space is part of personal space is its variability depending on the level of familiarity with others. The size of personal space is not fixed; it varies depending on the level of familiarity with others. Ariga (2016) reported that this feature is also reflected in owned objects. Our focus on this feature is why we use the term "personal space." While it is true that the "extension of personal space" shares similar characteristics with personal space in terms of variability based on familiarity with others, we agree with your point that the "extension of personal space" discussed in our study is not entirely the same as "personal space." As you pointed out, concepts such as the sense of ownership and territory are likely relevant to this phenomenon. To prevent readers from misunderstanding the same confusion as you, we have clarified the concept of “extension of personal space” in the original article: The end of the second paragraph in the introduction: “…extended to the space surrounding their belongings (i.e., extended personal space). The placement of such personal belongings can be considered the most significant evidence of an extension of personal space, as it shares the same characteristics with personal space (Russell & Ward, 1982; Becker, 1973), that the variability depending on the level of familiarity with others.” Additional references: Russell, J. A., & Ward, L. M. (1982). Environmental psychology. Annual Review of Psychology, 33, 651–688. https://doi.org/10.1146/annurev.ps.33.020182.003251 Becker, F. D. (1973). Study of spatial markers. Journal of Personality and Social Psychology, 26, 439–445. As for the second point you mentioned about the citation of Sasaki et al (2018), after checking, we agree that this citation is not optimal and potentially misleading here. The argument for this statement is also mentioned later in the paragraph, so we have deleted this sentence. Reviewer Comments: “Secondly, and more importantly, I found it highly challenging to assert that the effect observed by the authors is truly driven by the COVID-19 pandemic, given the limited measures they collected. While I acknowledge the inherent challenges in proving such causation, I suggest that the authors provide more information and/or conduct additional analyses to make the study more persuasive. Firstly, the authors should clearly state the size of the table and the position of the chair, ensuring they are indeed identical to those used in Ariga (2016). The authors should include this information in the main text, not just within a figure. I assume that the relative position of the chairs to the table would affect the participant’s behavior, as people tend to place objects directly in front of where they are seated. Thus, it is essential that these parameters were controlled between the studies. I also suggest the authors provide more information about the confederates, including their sexes and ages, because Ariga (2016) demonstrated that the relationship between the confederates' and participants' sexes had a clear effect on the results.” Author Reply: Thank you very much for pointing out the inadequacies in our description. For the purpose of controlling the possible influence of the experimental setting on the results, in the present experiment, we used a table of exactly the same size as Ariga (2016), and the positions of the chairs and table were exactly the same as in Ariga's (2016) study. Indeed, including these contents in the main text can help readers better eliminate concerns about the impact of experimental settings on the results, so we clearly stated the contents of this part in the main text. That said, we should consider other factors, than COVID-19, like mood, anxiety, or other person-related characteristics. Moreover, in our experiment, the confederates were three graduate male students who took turns according to their schedules. Their average age was 23.6 years old (the confederate in the original experiment was a 21-year-old male). We also added information about the gender and age of the confederates in the original text. Reviewer Comments: “Furthermore, I speculate that the size or number of the participants' belongings could affect the distance measures. It seems that Ariga (2016) considered only the participant’s bag, but what was the case in this study? If the authors have pictures of the placement of the belongings, they might be able to conduct additional analyses that could potentially rule out the influence of the size/number of the participant’s belongings on the findings.” Author Reply: Although we asked participants to come with their bags, we did not force them. Participants came with their bags, jackets, notebooks, and so on. Because we did not record the type of belongings as well as the size of them, it is difficult to analyze the effects of them. Instead, to control the effect of the size of the items on the results, we standardized the measurements by only measuring the minimum distance between two objects and did not include the size of the objects themselves. We believe that with this approach we can minimize the effect of object size on the results and make full use of the sample size. Reviewer Comments: “Ideally, it would have been valuable if the authors had collected some subjective scales related to the pandemic, such as how afraid the participants were of or how cautious they were about the infection. This could be a subject to consider for future studies.” Author Reply: Unfortunately, we did not measure subjective scales related to the pandemic. We added this point in the Discussion section for future research. Instead, the trend of the pandemic was added in the main text, following the other reviewer. Reviewer Comments: Minor points: “In the third paragraph of the Introduction, the authors reference Tootell et al., 2021, as a study that reported an increase in interpersonal distance during the pandemic. However, I believe that this study was conducted before the pandemic. Could it be that the authors intended to cite Holt et al., 2022 instead?” Author Reply: Thank you very much for pointing out our misunderstanding. Although this article (Tootell et al., 2021) was conducted during the period of COVID-19, the conclusion does not indicate the relationship between the increased interpersonal distance and COVID-19. Therefore, we accept your kind suggestion to cite Holt et al. (2022) and add a reference to Lachini et al. (2021) to increase the persuasiveness of the previous study. The details of the references are as follows: Iachini, T., Frassinetti, F., Ruotolo, F., Sbordone, F. L., Ferrara, A., Arioli, M., ... & Ruggiero, G. (2021). Social distance during the COVID-19 pandemic reflects perceived rather than actual risk. International Journal of Environmental Research and Public Health, 18 (11), 5504. Holt, D. J., Zapetis, S. L., Babadi, B., Zimmerman, J., & Tootell, R. B. (2022). Personal space increases during the COVID-19 pandemic in response to real and virtual humans. Frontiers in Psychology, 13 , 952998. We also revised our manuscript. Reviewer Comments: “The authors should clearly specify the timing of data collection within the Methods section of the main text.” Author Reply: Thank you for your advice. Although the experiment period was referred to in the abstract, we added the timeline of data collection in the method- participants part of the main text as follows: The experiment period was from June 10, 2022, to January 23, 2023. Reviewer Comments: “Upon reviewing the raw data provided by the authors, I noticed that it includes 70 data. If I understood correctly, there should only be 68 data since 2 participants did not bring any belongings. Please check this.” Author Reply: What you understand is correct. Two of the participants did not take any of their belongings to take part in the experiment. Therefore, the experimental conditions were not met, and we excluded the data from these two participants. Moreover, we have mentioned the exclusion in the main text as follows: we collected data from 70 participants; of these, two participants were excluded since they did not bring any belongings. Reviewer Comments: “This study did not find any effect of the confederate's friendliness on the participants' behavior. The authors claims that this result is inconsistent with findings from Ariga (2006), potentially due to a ceiling effect. However, since the ANOVA revealed only a main effect of experimental timing and the interaction was not significant, it may be misleading to definitively state that the findings are inconsistent regarding the effect of the confederate's friendliness.” Author Reply: Our study indeed did not find a significant effect of the confederate's friendliness on the participants' behavior, as indicated by the lack of a significant interaction in the ANOVA. We acknowledged this finding and compared it with the results from Ariga (2006), where friendliness did have an effect. In our discussion, we suggested that the inconsistency with Ariga (2006) might be due to a ceiling effect. The ceiling effect suggests that participants may have already reached a maximum level of performance or behavior, making it difficult to observe any additional effect of the confederate's friendliness. While this is a plausible explanation, we agree that it should be presented as a hypothesis rather than a definitive conclusion. To address your concern about the conclusiveness of our statement, we propose revising our discussion to indicate that the findings are suggestive rather than conclusive. Here is the revised statement: “Intriguingly, our study did not find a significant effect of the confederate's friendliness on participants' behavior, as indicated by the lack of a significant interaction effect in the ANOVA. This result appears to be inconsistent with the findings from Ariga (2016). One possible explanation for this discrepancy could be a ceiling effect, where participants' behavior might have already reached its peak, limiting the observable impact of additional friendliness.” View more View less Competing Interests No competing interests were disclosed. reply Respond Report a concern Isomura T. Peer Review Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.143432.r259293) NOTE: it is important to ensure the information in square brackets after the title is included in this citation. The direct URL for this report is: https://f1000research.com/articles/12-199/v1#referee-response-259293 keyboard_arrow_left Back to all reports Reviewer Report 0 Views copyright © 2023 Kroczek L. This is an open access peer review report distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 24 Jul 2023 | for Version 1 Leon O. H Kroczek , University of Regensburg, Regensburg, Germany 0 Views copyright © 2023 Kroczek L. This is an open access peer review report distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. format_quote Cite this report speaker_notes Responses (1) Not Approved info_outline Alongside their report, reviewers assign a status to the article: Approved The paper is scientifically sound in its current form and only minor, if any, improvements are suggested Approved with reservations A number of small changes, sometimes more significant revisions are required to address specific details and improve the papers academic merit. Not approved Fundamental flaws in the paper seriously undermine the findings and conclusions Summary: In the present, pre-registered study, participants were asked to place their belongings on a table together with the belongings of a confederate while the physical distance between personal belongings is measured as an outcome variable. These data are then compared to pre-pandemic data of the same paradigm from Ariga (2016). The authors find an increase in physical distance in the current compared to the original study and interpret these findings in the light of changes of social distances induced by the Covid-19 pandemic. The authors also investigate a within-subject manipulation, i.e. the influence of confederate friendliness on distance between belongings but do not find a significant effect and thus cannot replicate the results of Ariga (2016). Review: I think the present study uses an interesting and unobtrusive way to study interpersonal distance. I also applaud the authors for pre-registering their study. However, one major limitation of this study is that the main comparison is with respect to an unmatched group of participants almost 10 years ago, at a different university. The effects *could* be driven by changes in social distancing introduced by the Covid-19 pandemic, but there are also several other effects that could influence the data. The authors report that the sample had the same sex ratio as the original study, but what about other factors like mood, (social) anxiety, age, other person-related characteristics? Also trivial points, like whether the same kind of belongings were used between studies (jackets or handbags) might have influenced the results (e.g. jackets might fall from the table when placed too close to the border). Some of this is already discussed in the limitations but needs to be highlighted when making claims about Covid-19 related changes of behavior. In my view, it would be much more convincing if the authors could show that distance is influenced by a subjective variable related to perceived vulnerability to Covid-19 (e.g. individual fear of an infection, belief about importance of social distancing as a policy against spread of infection, fear for family members,…, but also belief about whether belonging can be the source of infections) or an objective variable like cases reported in the news, number of active restrictions due to the pandemic, availability of vaccines. It seems also to be the case that standard deviations were bigger in the present study, suggesting a stronger influence of individual characteristics. Anyway, this point needs to be made more clearly throughout the manuscript and should even be reported in the abstract. Side note: Looking in the pre-registration the effect of the within-subject factor “alcohol disinfection” could be also informative about that. As a related point, it would be great to get more information on the state of the pandemic at the test center during the test period. How many new infections were reported during this time? What were the active policies against spread of infections, was the topic very present in the media? I ask this because in Germany, in the second half of 2022 the pandemic was less of a topic than in the years before and there were (almost) no impacts of Covid-19 related restriction in everyday life. I wonder whether similar claims could be made about Japan during this time? In addition, it would strengthen the argument of the authors to describe how the actual distance between persons was related to the distance between belongings. Was the distance in belonging correlated to actual distancing? Please also include more details on the paradigm here: How big was the distance between chairs in the experimental setting? Was it closer or further than a minimum recommended distance? Could this influence the placing of belongings? The authors suggest that a ceiling effect precluded them from finding an effect of friendliness as in Ariga 2016. Looking at the distributions most of the distances were below 60 cm with the table being 150 cm wide (but please state where exactly on the table the belongings of the confederate where located), and original effect being around 10 cm. These data seem to suggest that the effect would have been observable if present. Another interpretation might therefore be that the belongings may not reflect personal space after all (contrary to Ariga, 2016). This should be discussed. Minor: I suggest to change the wording “peacetime” to “pre-pandemic” throughout I had difficulties understanding the first paragraph, maybe consider rephrasing it. Also there is more recent evidence on the relation of peripersonal space and interpersonal distance (e.g. see works of Yann Coello) Is the work clearly and accurately presented and does it cite the current literature? Partly Is the study design appropriate and is the work technically sound? No Are sufficient details of methods and analysis provided to allow replication by others? Partly If applicable, is the statistical analysis and its interpretation appropriate? Yes Are all the source data underlying the results available to ensure full reproducibility? Yes Are the conclusions drawn adequately supported by the results? No Competing Interests No competing interests were disclosed. Reviewer Expertise experimental psychology, social interaction research I confirm that I have read this submission and believe that I have an appropriate level of expertise to state that I do not consider it to be of an acceptable scientific standard, for reasons outlined above. reply Respond to this report Responses (1) Author Response 27 Aug 2024 Kaito Takashima, Graduate School of Human-Environment Studies, Kyushu University, Fukuoka, Japan Replies to the comments by Dr. Leon O. H Kroczek (University of Regensburg, Regensburg, Germany): Reviewer Comment: “I think the present study uses an interesting and unobtrusive way to study interpersonal distance. I also applaud the authors for pre-registering their study. However, one major limitation of this study is that the main comparison is with respect to an unmatched group of participants almost 10 years ago, at a different university. The effects *could* be driven by changes in social distancing introduced by the Covid-19 pandemic, but there are also several other effects that could influence the data. The authors report that the sample had the same sex ratio as the original study, but what about other factors like mood, (social) anxiety, age, other person-related characteristics? Also trivial points, like whether the same kind of belongings were used between studies (jackets or handbags) might have influenced the results (e.g. jackets might fall from the table when placed too close to the border). Some of this is already discussed in the limitations but needs to be highlighted when making claims about Covid-19 related changes of behavior.” Author Reply: Thank you for your comments. Unfortunately, the current evidence cannot assess the possibility that differences in data collection year, person-related characteristics, and university might influence the distance between inter-belongings. In addition, although the participants’ belongings were limited to bags in the previous study (Ariga, 2016), in the present study, we did not restrict participants to carry only bags. We agree with your comment that it is important to highlight this information when making claims about COVID-19-related changes in behavior. Thus, in the conclusion part, we added, “…the results show that people significantly increased, with a large effect size, the distance between personal belongings during the COVID-19 pandemic. It is important to note, however, that the results of the present experiment do not fully demonstrate that COVID-19 was the only factor that affected the expanded personal space between belongings.” As we stated in the Discussion section, our hypothesis was that the distance between objects to which the interpersonal relationship expands increased during the COVID-19 period, but we considered COVID-19 as just one possible reason for this. To avoid misunderstanding among readers and other researchers, we adjusted the tone of the descriptions related to the plausible explanations of our results in the Discussion section of the revised manuscript:" ... extended personal space increased during the period of COVID-19 pandemic, but we consider COVID-19 as one of the reasons for this change. " Reviewer Comment: “In my view, it would be much more convincing if the authors could show that distance is influenced by a subjective variable related to perceived vulnerability to Covid-19 (e.g. individual fear of an infection, belief about importance of social distancing as a policy against spread of infection, fear for family members,…, but also belief about whether belonging can be the source of infections) or an objective variable like cases reported in the news, number of active restrictions due to the pandemic, availability of vaccines. It seems also to be the case that standard deviations were bigger in the present study, suggesting a stronger influence of individual characteristics. Anyway, this point needs to be made more clearly throughout the manuscript and should even be reported in the abstract. Side note: Looking in the pre-registration the effect of the within-subject factor “alcohol disinfection” could be also informative about that.” Author Reply: Several studies related to personal distance during COVID-19, such as Fini et al. (2021), have shown that interpersonal distance is influenced by the perception of Realistic Threat, as measured through the COVID-19 threat. Moreover, previous research suggests that the public's practice of social distancing is not solely driven by the perception of infection but also by the social meaning of collective health (Fazio et al., 2021). We have added the following to the third paragraph of the introduction: “... which means that exposed people and objects may carry the coronavirus present in aerosols. Doremalen et al. (2020) compared the survivability of SARS-CoV-2 (leading to COVID-19) and SARS-CoV-1 on different surfaces. They found that the survival time of SARS-CoV-2 on various material surfaces ranged from a few hours to a few days, suggesting that the surface of an item can be a potential pathway for virus transmission. Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) have also mentioned that the virus can be transmitted through direct contact with contaminated surfaces.” We greatly appreciate your suggestion to include these previous research findings in the manuscript and the abstract. This will help clarify to readers that the increased distance between belongings during COVID-19 may be influenced by the perceived threat that objects can also be a source of infection. Regarding the “alcohol disinfection” condition, it belonged to another experiment in our lab. For this experiment, we can only provide the results, which indicate that expanded personal space does not change depending on hand disinfection. Reviewer Comment: “As a related point, it would be great to get more information on the state of the pandemic at the test center during the test period. How many new infections were reported during this time? What were the active policies against spread of infections, was the topic very present in the media? I ask this because in Germany, in the second half of 2022 the pandemic was less of a topic than in the years before and there were (almost) no impacts of Covid-19 related restriction in everyday life. I wonder whether similar claims could be made about Japan during this time?” Author Reply: We utilized Google Trends to track the frequency of the keyword "コロナ" (Japanese term for COVID-19) in Google searches. The data revealed that media coverage of COVID-19 in Japan fluctuated significantly, with the peak occurring at the onset of the pandemic in early 2020. Our experiment took place from June 2022 to January 2023, during which time the final wave of COVID-19 peaked, and media coverage remained high. However, by January 2023, media coverage started to decrease. Additionally, COVID-19-related information was widely disseminated not only through news and entertainment media but also in public places such as restaurants and shopping malls, where social distancing and health and safety measures were prominently displayed. According to Japanese news reports [Please refer to the below links for Image 1 and Image 2] , the number of new COVID-19 infections across Japan exceeded 40,000 per day starting in June 2022, reaching over 100,000 per day by July 2022. This marked the highest number of cases since the initial outbreak of COVID-19 in Japan in 2020. Image 1 Reference link: https://f1000research.s3.amazonaws.com/linked/669428.Image_1.pdf Image 2 Reference link: https://f1000research.s3.amazonaws.com/linked/669429.Image_2.pdf Reviewer Comment: “In addition, it would strengthen the argument of the authors to describe how the actual distance between persons was related to the distance between belongings. Was the distance in belonging correlated to actual distancing?” Author Reply: While we believe that our current findings reflect the physical distance between the confederate and the participant, we did not measure this distance during the actual experiment. Instead, we fixed their physical distance to eliminate any potential influence that physical distance might have had on the placement of objects, as it could have affected the results. Reviewer Comment: “Please also include more details on the paradigm here: How big was the distance between chairs in the experimental setting? Was it closer or further than a minimum recommended distance? Could this influence the placing of belongings?” Author Reply: The distance between the two chairs was approximately 30-40 cm, significantly less than the recommended social distancing measure of 2 meters due to the constraints of the experiment room's size and layout. The small distance between chairs may have created a sense of social anxiety and constriction at the beginning, making participants place belongings farther away to alleviate seated proximity in subsequent place sessions. No studies have been done to illustrate the effect of physical proximity on the unraveling of the distance between items. We added this part of the influence of chair distance on the distance of placing objects in the limitation part. "... as they were unsure whether the stranger and their belongings were infected with viruses. Moreover, some previous studies declared that the confined spaces may enhance the feeling of personal space invasion, thereby increasing psychological stress and anxiety (Aiello et al ., 1977; Evans, & Wener, 2007). In the present study, for strict replication and fair comparison, the chair distance was set to be the same as in the original experiment conducted in the pre-pandemic period, but the small distance between chairs may have created a sense of social anxiety and constriction at the beginning, making participants place belongings farther away to alleviate seated proximity in subsequent place sessions. No studies that have been done to illustrate the effect of physical proximity on the unraveling of the distance between items. "... and sat next to the confederate’s chair. The distance between two chairs was roughly 30-40 cm." in the Procedure section. Reviewer Comment: “The authors suggest that a ceiling effect precluded them from finding an effect of friendliness as in Ariga 2016. Looking at the distributions most of the distances were below 60 cm with the table being 150 cm wide (but please state where exactly on the table the belongings of the confederate where located), and original effect being around 10 cm. These data seem to suggest that the effect would have been observable if present. Another interpretation might therefore be that the belongings may not reflect personal space after all (contrary to Ariga, 2016). This should be discussed.” Author Reply: Thank you for your insightful comment. Our manuscript lacked a crucial piece of information: the size of the confederate's belongings, which is approximately 36 cm wide. We have now included this detail in our manuscript. Although the confederate experimenters tried to place their belongings as far as possible to the left corner of the desks, the space left for the participants was estimated to be around 100-110 cm. Additionally, the maximum distance between the belongings would be approximately 60 cm, assuming the participant's belongings were about 40 cm wide. Attempting to increase the distance by 10 cm from the unfriendly confederate's belongings to the average brings it close to the maximum possible distance. Participants might have avoided placing their belongings in the corners due to concerns about them falling. We believe that if the desks had been longer, participants could have placed their belongings further from the unfriendly confederate's belongings without the risk of them falling. Based on this context, we interpreted the results as being influenced by a ceiling effect. Your comment helped us identify and address this missing information. Reviewer Comment: Minor: “I suggest to change the wording “peacetime” to “pre-pandemic” throughout.” Author Reply: We changed it to “pre-pandemic”. Reviewer Comment: “I had difficulties understanding the first paragraph, maybe consider rephrasing it. Also there is more recent evidence on the relation of peripersonal space and interpersonal distance (e.g. see works of Yann Coello)” Author Reply: Thank you for your comments. We have rewritten the first paragraph and added new studies to help clarify our logic for you and the readers. “Social psychology and proxemics have long addressed personal space as the spatial range surrounding the individual (Sommer, 1959; Hall, 1966). The space around them represents a mediation zone between the body and the environment, contributing to the organization of social life. For example, when this space is encroached by others, we may feel uncomfortable or may prepare our bodies for defensive responses (Hall, 1966; Coello and Cartaud, 2021). However, the center of personal space is oneself, but it is not restricted to the physical body; much evidence proposed that the concept of self is expanding in space and timeline. For example, the ‘cutaneous rabbit’ can be felt not only on one’s body but also on an object that one is grasping (Miyazaki et al., 2010). The line of sight away from the eye can still be perceived as exerting force on the object (Guterstam et al., 2019). Furthermore, the extension of body representations to objects has been observed in neuroscience (Iriki et al., 1996). As a result, personal space boundaries also expand with the extension of body perception.” View more View less Competing Interests No competing interests were disclosed. reply Respond Report a concern Kroczek LOH. Peer Review Report For: Social distancing between personal belongings during the COVID-19 pandemic [version 3; peer review: 2 approved, 2 approved with reservations] . F1000Research 2025, 12 :199 ( https://doi.org/10.5256/f1000research.143432.r186686) NOTE: it is important to ensure the information in square brackets after the title is included in this citation. The direct URL for this report is: https://f1000research.com/articles/12-199/v1#referee-response-186686 Alongside their report, reviewers assign a status to the article: Approved - the paper is scientifically sound in its current form and only minor, if any, improvements are suggested Approved with reservations - A number of small changes, sometimes more significant revisions are required to address specific details and improve the papers academic merit. Not approved - fundamental flaws in the paper seriously undermine the findings and conclusions Adjust parameters to alter display View on desktop for interactive features Includes Interactive Elements View on desktop for interactive features Competing Interests Policy Provide sufficient details of any financial or non-financial competing interests to enable users to assess whether your comments might lead a reasonable person to question your impartiality. Consider the following examples, but note that this is not an exhaustive list: Examples of 'Non-Financial Competing Interests' Within the past 4 years, you have held joint grants, published or collaborated with any of the authors of the selected paper. You have a close personal relationship (e.g. parent, spouse, sibling, or domestic partner) with any of the authors. You are a close professional associate of any of the authors (e.g. scientific mentor, recent student). You work at the same institute as any of the authors. You hope/expect to benefit (e.g. favour or employment) as a result of your submission. You are an Editor for the journal in which the article is published. Examples of 'Financial Competing Interests' You expect to receive, or in the past 4 years have received, any of the following from any commercial organisation that may gain financially from your submission: a salary, fees, funding, reimbursements. You expect to receive, or in the past 4 years have received, shared grant support or other funding with any of the authors. You hold, or are currently applying for, any patents or significant stocks/shares relating to the subject matter of the paper you are commenting on. Stay Updated Sign up for content alerts and receive a weekly or monthly email with all newly published articles Register with F1000Research Already registered? Sign in Not now, thanks close PLEASE NOTE If you are an AUTHOR of this article, please check that you signed in with the account associated with this article otherwise we cannot automatically identify your role as an author and your comment will be labelled as a “User Comment”. If you are a REVIEWER of this article, please check that you have signed in with the account associated with this article and then go to your account to submit your report, please do not post your review here. If you do not have access to your original account, please contact us . All commenters must hold a formal affiliation as per our Policies . The information that you give us will be displayed next to your comment. User comments must be in English, comprehensible and relevant to the article under discussion. We reserve the right to remove any comments that we consider to be inappropriate, offensive or otherwise in breach of the User Comment Terms and Conditions . Commenters must not use a comment for personal attacks. When criticisms of the article are based on unpublished data, the data should be made available. I accept the User Comment Terms and Conditions Please confirm that you accept the User Comment Terms and Conditions. Affiliation ✕ refresh Please enter your institution. Note: To add your institution or organisation, start typing the name and then select the correct name from the list. Where applicable, the name will appear in both the original language and in English. Do not paste in the name. If the name does not appear in the drop-down list, we will display the information you have entered. ✕ refresh Country/Region * USA UK Canada China France Germany Afghanistan Aland Islands Albania Algeria American Samoa Andorra Angola Anguilla Antarctica Antigua and Barbuda Argentina Armenia Aruba Australia Austria Azerbaijan Bahamas Bahrain Bangladesh Barbados Belarus Belgium Belize Benin Bermuda Bhutan Bolivia Bosnia and Herzegovina Botswana Bouvet Island Brazil British Indian Ocean Territory British Virgin Islands Brunei Bulgaria Burkina Faso Burundi Cambodia Cameroon Canada Cape Verde Cayman Islands Central African Republic Chad Chile China Christmas Island Cocos (Keeling) Islands Colombia Comoros Congo Cook Islands Costa Rica Cote d'Ivoire Croatia Cuba Cyprus Czech Republic Democratic Republic of the Congo Denmark Djibouti Dominica Dominican Republic Ecuador Egypt El Salvador Equatorial Guinea Eritrea Estonia Ethiopia Falkland Islands Faroe Islands Federated States of Micronesia Fiji Finland France French Guiana French Polynesia French Southern Territories Gabon Georgia Germany Ghana Gibraltar Greece Greenland Grenada Guadeloupe Guam Guatemala Guernsey Guinea Guinea-Bissau Guyana Haiti Heard Island and Mcdonald Islands Holy See (Vatican City State) Honduras Hong Kong Hungary Iceland India Indonesia Iran Iraq Ireland Israel Italy Jamaica Japan Jersey Jordan Kazakhstan Kenya Kiribati Kosovo (Serbia and Montenegro) Kuwait Kyrgyzstan Lao People's Democratic Republic Latvia Lebanon Lesotho Liberia Libya Liechtenstein Lithuania Luxembourg Macao Madagascar Malawi Malaysia Maldives Mali Malta Marshall Islands Martinique Mauritania Mauritius Mayotte Mexico Minor Outlying Islands of the United States Moldova Monaco Mongolia Montenegro Montserrat Morocco Mozambique Myanmar Namibia Nauru Nepal Netherlands Antilles New Caledonia New Zealand Nicaragua Niger Nigeria Niue Norfolk Island North Korea North Macedonia Northern Mariana Islands Norway Oman Pakistan Palau Palestinian Territory Panama Papua New Guinea Paraguay Peru Philippines Pitcairn Poland Portugal Puerto Rico Qatar Reunion Romania Russian Federation Rwanda Saint Helena Saint Kitts and Nevis Saint Lucia Saint Pierre and Miquelon Saint Vincent and the Grenadines Samoa San Marino Sao Tome and Principe Saudi Arabia Senegal Serbia Seychelles Sierra Leone Singapore Slovakia Slovenia Solomon Islands Somalia South Africa South Georgia and the South Sandwich Is South Korea South Sudan Spain Sri Lanka Sudan Suriname Svalbard and Jan Mayen Swaziland Sweden Switzerland Syria Taiwan Tajikistan Tanzania Thailand The Gambia The Netherlands Timor-Leste Togo Tokelau Tonga Trinidad and Tobago Tunisia Turkey Turkmenistan Turks and Caicos Islands Tuvalu UK USA Uganda Ukraine United Arab Emirates United States Virgin Islands Uruguay Uzbekistan Vanuatu Venezuela Vietnam Wallis and Futuna West Bank and Gaza Strip Western Sahara Yemen Zambia Zimbabwe Please select your country/region. You must enter a comment. Competing Interests Please disclose any competing interests that might be construed to influence your judgment of the article's or peer review report's validity or importance. Competing Interests Policy Provide sufficient details of any financial or non-financial competing interests to enable users to assess whether your comments might lead a reasonable person to question your impartiality. Consider the following examples, but note that this is not an exhaustive list: Examples of 'Non-Financial Competing Interests' Within the past 4 years, you have held joint grants, published or collaborated with any of the authors of the selected paper. You have a close personal relationship (e.g. parent, spouse, sibling, or domestic partner) with any of the authors. You are a close professional associate of any of the authors (e.g. scientific mentor, recent student). You work at the same institute as any of the authors. You hope/expect to benefit (e.g. favour or employment) as a result of your submission. You are an Editor for the journal in which the article is published. Examples of 'Financial Competing Interests' You expect to receive, or in the past 4 years have received, any of the following from any commercial organisation that may gain financially from your submission: a salary, fees, funding, reimbursements. You expect to receive, or in the past 4 years have received, shared grant support or other funding with any of the authors. You hold, or are currently applying for, any patents or significant stocks/shares relating to the subject matter of the paper you are commenting on. Please state your competing interests The comment has been saved. An error has occurred. Please try again. Cancel Post var lTitle = "Social distancing between personal belongings...".replace("'", ''); var linkedInUrl = "http://www.linkedin.com/shareArticle?url=https://f1000research.com/articles/12-199/v3" + "&title=" + encodeURIComponent(lTitle) + "&summary=" + encodeURIComponent('Read the article by '); var deliciousUrl = "https://del.icio.us/post?url=https://f1000research.com/articles/12-199/v3&title=" + encodeURIComponent(lTitle); var redditUrl = "http://reddit.com/submit?url=https://f1000research.com/articles/12-199/v3" + "&title=" + encodeURIComponent(lTitle); linkedInUrl += encodeURIComponent('Guo W et al.'); var offsetTop = /chrome/i.test( navigator.userAgent ) ? 4 : -10; var addthis_config = { ui_offset_top: offsetTop, services_compact : "facebook,twitter,www.linkedin.com,www.mendeley.com,reddit.com", services_expanded : "facebook,twitter,www.linkedin.com,www.mendeley.com,reddit.com", services_custom : [ { name: "LinkedIn", url: linkedInUrl, icon:"/img/icon/at_linkedin.svg" }, { name: "Mendeley", url: "http://www.mendeley.com/import/?url=https://f1000research.com/articles/12-199/v3/mendeley", icon:"/img/icon/at_mendeley.svg" }, { name: "Reddit", url: redditUrl, icon:"/img/icon/at_reddit.svg" }, ] }; var addthis_share = { url: "https://f1000research.com/articles/12-199", templates : { twitter : "Social distancing between personal belongings during the COVID-19.... Guo W et al., published by " + "@F1000Research" + ", https://f1000research.com/articles/12-199/v3" } }; if (typeof(addthis) != "undefined"){ addthis.addEventListener('addthis.ready', checkCount); addthis.addEventListener('addthis.menu.share', checkCount); } $(".f1r-shares-twitter").attr("href", "https://twitter.com/intent/tweet?text=" + addthis_share.templates.twitter); $(".f1r-shares-facebook").attr("href", "https://www.facebook.com/sharer/sharer.php?u=" + addthis_share.url); $(".f1r-shares-linkedin").attr("href", addthis_config.services_custom[0].url); $(".f1r-shares-reddit").attr("href", addthis_config.services_custom[2].url); $(".f1r-shares-mendelay").attr("href", addthis_config.services_custom[1].url); function checkCount(){ setTimeout(function(){ $(".addthis_button_expanded").each(function(){ var count = $(this).text(); if (count !== "" && count != "0") $(this).removeClass("is-hidden"); else $(this).addClass("is-hidden"); }); }, 1000); } close How to cite this report {{reportCitation}} Cancel Copy Citation Details $(function(){R.ui.buttonDropdowns('.dropdown-for-downloads');}); $(function(){R.ui.toolbarDropdowns('.toolbar-dropdown-for-downloads');}); $.get("/articles/acj/130662/177402") new F1000.Clipboard(); new F1000.ThesaurusTermsDisplay("articles", "article", "177402"); $(document).ready(function() { $( "#frame1" ).on('load', function() { var mydiv = $(this).contents().find("div"); var h = mydiv.height(); console.log(h) }); var tooltipLivingFigure = jQuery(".interactive-living-figure-label .icon-more-info"), titleLivingFigure = tooltipLivingFigure.attr("title"); tooltipLivingFigure.simpletip({ fixed: true, position: ["-115", "30"], baseClass: 'small-tooltip', content:titleLivingFigure + " " }); tooltipLivingFigure.removeAttr("title"); $("body").on("click", ".cite-living-figure", function(e) { e.preventDefault(); var ref = $(this).attr("data-ref"); $(this).closest(".living-figure-list-container").find("#" + ref).fadeIn(200); }); $("body").on("click", ".close-cite-living-figure", function(e) { e.preventDefault(); $(this).closest(".popup-window-wrapper").fadeOut(200); }); $(document).on("mouseup", function(e) { var metricsContainer = $(".article-metrics-popover-wrapper"); if (!metricsContainer.is(e.target) && metricsContainer.has(e.target).length === 0) { $(".article-metrics-close-button").click(); } }); var articleId = $('#articleId').val(); if($("#main-article-count-box").attachArticleMetrics) { $("#main-article-count-box").attachArticleMetrics(articleId, { articleMetricsView: true }); } }); var figshareWidget = $(".new_figshare_widget"); if (figshareWidget.length > 0) { window.figshare.load("f1000", function(Widget) { // Select a tag/tags defined in your page. In this tag we will place the widget. _.map(figshareWidget, function(el){ var widget = new Widget({ articleId: $(el).attr("figshare_articleId") //height:300 // this is the height of the viewer part. [Default: 550] }); widget.initialize(); // initialize the widget widget.mount(el); // mount it in a tag that's on your page // this will save the widget on the global scope for later use from // your JS scripts. This line is optional. //window.widget = widget; }); }); } close Error Close Add Reset F1000.MICROSERVICES.AFFILIATION = ''; $(document).ready(function () { $('.js-affiliations-form').each((index, form) => { new AffiliationForm({ formId: form.id, institutionErrorSelector: '.comment-enter-institution', departmentErrorSelector: '.comment-enter-department', placeSelector: '.js-add-comment-place', stateSelector: '.js-add-comment-state', zipCodeSelector: '.js-add-comment-zipcode', countrySelector: '.js-add-comment-country', countryErrorSelector: '.comment-enter-country', }); }); }); $(document).ready(function () { var reportIds = { "218115": 0, "218112": 0, "231444": 0, "186682": 0, "186686": 80, "186690": 0, "186691": 0, "249666": 0, "186694": 0, "186695": 0, "186692": 0, "186698": 0, "186696": 0, "186697": 0, "223823": 0, "328021": 0, "177747": 0, "328020": 0, "328023": 0, "223824": 0, "328022": 0, "177750": 0, "177751": 0, "177748": 0, "328019": 0, "177749": 0, "328018": 0, "177754": 0, "177755": 0, "177752": 0, "177753": 0, "249695": 0, "328025": 0, "249694": 0, "328024": 0, "177756": 0, "328027": 0, "328026": 0, "249699": 0, "249698": 0, "249697": 0, "249696": 0, "249701": 0, "249700": 0, "249961": 0, "180858": 0, "180859": 0, "180856": 0, "180857": 0, "198271": 0, "180862": 0, "198270": 0, "180863": 0, "180860": 0, "180861": 0, "180866": 0, "180864": 0, "198279": 0, "198291": 0, "164243": 0, "198295": 0, "164246": 0, "164247": 0, "164244": 0, "198292": 0, "164245": 0, "198298": 0, "198297": 0, "198296": 0, "168863": 0, "259229": 0, "198300": 0, "345498": 0, "365479": 0, "337830": 0, "365485": 0, "365484": 33, "365487": 0, "365486": 0, "365481": 0, "365480": 0, "365483": 0, "337835": 0, "365482": 0, "330677": 0, "330676": 0, "330679": 0, "330678": 0, "337841": 0, "330673": 0, "365488": 0, "330672": 0, "330675": 0, "330674": 0, "330681": 0, "330680": 0, "364741": 22, "364740": 13, "364739": 16, "165068": 0, "345557": 0, "317654": 0, "345559": 0, "348887": 0, "317655": 0, "345558": 0, "259286": 0, "259291": 0, "324572": 0, "324573": 0, "259289": 0, "324574": 0, "259288": 0, "324575": 0, "259295": 0, "348889": 23, "259294": 0, "345560": 0, "348888": 0, "265178": 0, "259293": 41, "324570": 0, "259292": 0, "265179": 0, "348890": 0, "324571": 0, "324576": 0, "324577": 0, "324578": 0, "324579": 0, "334573": 0, "334572": 0, "334575": 0, "334574": 0, "334571": 0, "334570": 0, "218097": 0, "218103": 0, "334577": 0, "218102": 0, "334576": 0, "218101": 0, "232181": 0, "334579": 0, "334578": 0, "218106": 0, "218105": 0, "218104": 0, "218109": 0, }; $(".referee-response-container,.js-referee-report").each(function(index, el) { var reportId = $(el).attr("data-reportid"), reportCount = reportIds[reportId] || 0; $(el).find(".comments-count-container,.js-referee-report-views").html(reportCount); }); var uuidInput = $("#article_uuid"), oldUUId = uuidInput.val(), newUUId = "cc82e23b-c56f-4ee9-ba2f-7ec5a5d1db34"; uuidInput.val(newUUId); $("a[href*='article_uuid=']").each(function(index, el) { var newHref = $(el).attr("href").replace(oldUUId, newUUId); $(el).attr("href", newHref); }); }); An innovative open access publishing platform offering rapid publication and open peer review, whilst supporting data deposition and sharing. Browse Gateways Collections How it Works Contact For Developers Cookie Notice Privacy Notice RSS Submit Your Research Follow us © 2012-2026 F1000 Research Ltd. ISSN 2046-1402 | Legal | Partner of Research4Life • CrossRef • ORCID • FAIRSharing R.templateTests.simpleTemplate = R.template(' $text $text $text $text $text '); R.templateTests.runTests(); var F1000platform = new F1000.Platform({ name: "f1000research", displayName: "F1000Research", hostName: "f1000research.com", id: "1", editorialEmail: "[email protected]", infoEmail: "[email protected]", usePmcStats: true }); $(function(){R.ui.dropdowns('.dropdown-for-authors, .dropdown-for-about, .dropdown-for-myresearch');}); // $(function(){R.ui.dropdowns('.dropdown-for-referees');}); $(document).ready(function () { if ($(".cookie-warning").is(":visible")) { $(".sticky").css("margin-bottom", "35px"); $(".devices").addClass("devices-and-cookie-warning"); } $(".cookie-warning .close-button").click(function (e) { $(".devices").removeClass("devices-and-cookie-warning"); $(".sticky").css("margin-bottom", "0"); }); $("#tweeter-feed .tweet-message").each(function (i, message) { var self = $(message); self.html(linkify(self.html())); }); $(".partner").on("mouseenter mouseleave", function() { $(this).find(".gray-scale, .colour").toggleClass("is-hidden"); }); }); Sign In Remember me Forgotten your password? Sign In Cancel Email or password not correct. Please try again Please wait... $(function(){ // Note: All the setup needs to run against a name attribute and *not* the id due the clonish // nature of facebox... $("a[id=googleSignInButton]").click(function(event){ event.preventDefault(); $("input[id=oAuthSystem]").val("GOOGLE"); $("form[id=oAuthForm]").submit(); }); $("a[id=facebookSignInButton]").click(function(event){ event.preventDefault(); $("input[id=oAuthSystem]").val("FACEBOOK"); $("form[id=oAuthForm]").submit(); }); $("a[id=orcidSignInButton]").click(function(event){ event.preventDefault(); $("input[id=oAuthSystem]").val("ORCID"); $("form[id=oAuthForm]").submit(); }); }); If you've forgotten your password, please enter your email address below and we'll send you instructions on how to reset your password. The email address should be the one you originally registered with F1000. Email address not valid, please try again You registered with F1000 via Google, so we cannot reset your password. To sign in, please click here . If you still need help with your Google account password, please click here . You registered with F1000 via Facebook, so we cannot reset your password. To sign in, please click here . If you still need help with your Facebook account password, please click here . Code not correct, please try again Reset password Cancel Email us for further assistance. Server error, please try again. If your email address is registered with us, we will email you instructions to reset your password. If you think you should have received this email but it has not arrived, please check your spam filters and/or contact for further assistance. Please wait... Register $(document).ready(function () { signIn.createSignInAsRow($("#sign-in-form-gfb-popup")); $(".target-field").each(function () { var uris = $(this).val().split("/"); if (uris.pop() === "login") { $(this).val(uris.toString().replace(",","/")); } }); });