Testing a cognitive consistency account of the postidentification feedback effect

Abstract

The distortion of eyewitness confidence by postidentification feedback represents a major challenge to the use of eyewitness evidence, yet there is no coherent theoretical explanation of the psychological processes governing distortion. We tested a cognitive consistency account of this phenomenon, manipulating pressure to choose or reject the lineup (via pre-lineup instructions) and postidentification feedback (confirming, disconfirming or no feedback) in a between-subjects factorial design (N = 538). Results support the consistency account with larger effects of confirming feedback on choosers’ confidence when the opportunity to reject the lineup was highlighted. Nonchoosers showed greater distortion when they were told they were wrong and had been pressured to choose.