Abstract
•Prisoners who made unbidden confessions (UC) more confident they would be caught.•UC was made to someone with a stake in transgressor’s genetic interests.•Results suggest mismatch in efficacy of UC today compared with ancestral past.
Unbidden confession—confession made by a transgressor in the absence of interrogation—presents an evolutionary puzzle because it guarantees social exposure and places the person at risk of punishment. We hypothesize that unbidden confession may be an ancestrally adaptive behavior and is difficult to inhibit under certain social conditions, particularly when one perceives imminent and inevitable social exposure. This serves as a pre-emptive strategy that, in the ancestral past, may have attenuated punishment from retributive in-group members. Using self-report data from a sample of 78 federal inmates, we report analyses supporting this hypothesis. Inmates who made unbidden confessions were more confident that they would be caught by police, and this confession was usually made to someone who had a stake in the transgressors’ genetic interests, most often a family member or friend. These results suggest: (1) a possible role for natural selection in shaping cognitive mechanisms that motivate confession; (2) a potential mismatch in the efficacy of unbidden confession today compared with our ancestral past, given that the law is now administered by strangers rather than in-group members; and (3) new avenues for research on the origins of sophisticated cognitive strategies.