Memory distortion in eyewitnesses: A meta-analysis of the post-identification feedback effect

Abstract

Feedback administered to eyewitnesses after they make a line-up identification dramatically distorts a wide range of retrospective judgements (e.g. G. L. Wells & A. L. Bradfield, 1998 Journal of Applied Psychology, 83(3), 360-376.). This paper presents a meta-analysis of extant research on post-identification feedback, including 20 experimental tests with over 2400 participant-witnesses. The effect of confirming feedback (i.e. 'Good, you identified the suspect') was robust. Large effect sizes were obtained for most dependent measures, including the key measures of retrospective certainty, view and attention. Smaller effect sizes were obtained for so-called objective measures (e.g. length of time the culprit was in view) and comparisons between disconfirming feedback and control conditions. This meta-analysis demonstrates the reliability and robustness of the post-identification feedback effect. It reinforces recommendations for double-blind testing, recording of eyewitness reports immediately after an identification is made, and reconsideration by court systems of variables currently recommended for consideration in eyewitness evaluations. Copyright © 2006 John Wiley & Sons, Ltd.