The Effect of Post-ID Feedback on Retrospective Self-Reports in Showups

This study examined the effects of post-identification feedback on witness retrospective self-reports in showups and lineups, and importantly, focused on guilty and innocent suspect identifications. After viewing a mock crime video, participants were asked to identify the suspect from either a target-present or target-absent photo lineup or showup. Participants were randomly assigned to receive confirming feedback (“Great job, you made the correct decision”) or no feedback about their identification, before self-reporting confidence, view, attention, willingness to testify, and trust of a witness with a similar view. We replicated the typical finding that confirming feedback inflated witness self-reports and resulted in a larger proportion of witnesses meeting the credibility threshold necessary to testify. Importantly, we also found that showups had significantly higher self-reports than lineups, despite the equal discriminability achieved in this study between these two procedures. These data provide yet another reason for the police to restrict use of showups.