Dangerous decisions: the impact of first impressions of trustworthiness on the evaluation of legal evidence and defendant culpability

There is little support for the long-standing assumption that judges and jurors can accurately assess credibility. According to Dangerous Decisions Theory (DDT; Porter & ten Brinke, Legal and Criminological Psychology, 14, 119-134, 2009), intuitive evaluations of trustworthiness based on the face may strongly bias the interpretation of subsequent information about a target. In a courtroom setting, the assessment of evidence provided by or concerning a defendant may be fundamentally flawed if its interpretation is influenced by an initial, spontaneous assessment of trustworthiness. In an empirical test of DDT, participants were presented with two vignettes describing major or minor crimes, accompanied by a photograph of the supposed defendant, previously rated as highly trustworthy or untrustworthy in appearance. Participants evaluated culpability following the presentation of evidence in each case. Participants required less evidence to arrive at a guilty verdict and were more confident in this decision for untrustworthy-appearing defendants. The current evidence supports DDT and has implications for legal decision-making practices.