Study Objectives
Despite centuries of using sleep deprivation to interrogate, there is virtually no scientific evidence on how sleep shapes behavior within interrogation settings. To evaluate the impact of sleeplessness on subjects’ behavior during investigative interviews, an experimental study examined the impact of sleep restriction on disclosure of past illegal behavior.
Methods
Healthy participants from a university community (N=143) either maintained or curbed their sleep (up to 4 hours a night) across two days with sleep monitored via actigraphy. They were then asked to disclose past illegal acts and interviewed about them. Next, they were re-interviewed following an example of a detailed memory account (model statement). Disclosures were blindly coded for quantity and quality by two independent raters.
Results
Sleep-restricted individuals reported similar offenses, but less information during their disclosure with slightly less precision. Model statement increased disclosure but did not reduce the inhibiting impact of sleep loss. Mediation analysis confirmed the causal role of sleep as responsible for experimental differences in amount of information, and subjects’ reports suggested impaired motivation to recall information played a role.
Conclusions
The findings suggest that even moderate sleep loss can inhibit criminal disclosure during interviews, point to motivational factors as responsible, and suggest investigators should be cautious when interrogating sleepy subjects.