A jsPsych plugin for the Inclusion of Other in the Self (IOS) Scale

We present a web-based implementation of the Inclusion of Other in the Self (IOS) Scale written as a plugin for the popular jsPsych library. The IOS Scale measures perceived relational closeness, visually represented by the degree of overlap of a pair of circles, and is widely used to study interpersonal relationships. In contrast to the original 7-point discrete scale, the current tool allows for continuous measurements. Moreover, through changes of parameters, it can be configured to implement measures beyond the IOS Scale that use overlapping circles to represent relational closeness (e.g., measures of identity fusion).