The malleability of eyewitness confidence: Co-witness and perseverance effects.

A theft was staged 70 times for pairs of eyewitnesses (N?=?140) who then made a photo-lineup identification. Witnesses then received 1 of 9 types of information regarding the alleged identification decision of their co-witness. Witnesses told that their co-witness identified the same person whom they had identified showed an increase in the confidence they expressed to a confederate police officer. Confidence deflation occurred among witnesses who thought their co-witness either identified another person or had stated that the thief was not in the lineup. Initial co-witness information was not mitigated by subsequent changes to that information. A 2nd study showed videotapes of these witnesses' testimonies to observers (n?=?378) whose credibility ratings of the testimony paralleled the witnesses' self-rated confidence. Eyewitness identification confidence was highly malleable after the identification had been made despite the fact that physical resemblance between the culprit and person identified had not changed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)