The eyewitness post identification feedback effect 15 years later: Theoretical and policy implications.

Abstract

Eyewitnesses' retrospective reports of certainty, view, attention, and other judgments constitute central variables used by courts to assess the credibility of eyewitness identification evidence. Recently, important state Supreme Court decisions (e.g., New Jersey v. Henderson, 2011; Oregon v. Lawson, 2012) have relied on psychological research regarding the post-identification feedback effect to revamp their assumptions about when witness retrospective self-reports can be trusted. The post-identification feedback effect, originally demonstrated by Wells and Bradfield (1998), refers to the way in which witness self-reports are distorted by feedback to the witnesses that suggests that their identifications were accurate or mistaken. We present a meta-analysis of the post-identification effect involving 7,000 participants from the United States, Canada, Europe, and Australia. The results show that confirming feedback robustly inflates eyewitnesses' retrospective judgments across experimental manipulations and laboratory settings with large effect sizes. We describe the policy implications of the feedback effect with regard to the need for double-blind lineup procedures. Moreover, we propose that testimony-relevant witness judgments should be collected and documented, preferably with videotape, before feedback can occur. We use moderator analyses to examine the current explanation of the feedback effect and delineate new research questions that could help develop a more complete theoretical understanding of the processes giving rise to the effect.