Looking guilty: Handcuffing suspects influences judgments of deception

Detecting deception is an important task in legal and investigative contexts, where the outcome of a charging decision or criminal trial can hang on the credibility of victim, witness or suspect testimony. However, people are poor judges of deception, often relying on incorrect nonverbal cues for their decision, when such behaviors may reflect the situation more than the sender’s internal state. Over two studies, we investigated one such situational factor relevant to forensic contexts: handcuffing suspects. Suspects provided truthful and deceptive responses in an interrogation setting, where half were in handcuffs. We investigated how suspects were judged by (a) an interrogator who was in the room, and (b) observers watching video recordings, either laypeople or police officers. Handcuffing was predicted to undermine efforts to detect deception, either by constraining suspects' gesticulation or by activating stereotypes associated with criminality. Indeed, handcuffing affected both suspect behavior (Study 1) and observers’ veracity judgments (Study 2). The findings highlight the need for research on situational factors, to inform deception detection and forensic practice.