Postidentification feedback affects subsequent eyewitness identification performance.

Abstract

Eyewitnesses sometimes view more than one lineup during an investigation. We investigated the effects of postidentification feedback following one lineup on responses to a second lineup. Witnesses (N=621) viewed a mock crime and, later, attempted to identify the culprit from an initial (target-absent) lineup and a second (target-present or target-absent) lineup. Prior to viewing the second lineup, some witnesses received accurate feedback stating that the initial lineup did not contain the culprit. A compound-decision, signal detection approach allowed the effects of feedback on identification responses to be described in terms of differences in discriminability and response bias. For witnesses who made an incorrect foil identification from the initial lineup, feedback (vs. no feedback) was associated with poorer discriminability on the second test. For witnesses who correctly rejected the initial lineup, feedback (vs. no feedback) was associated with greater discriminability on the second test. Only witnesses who received feedback after an initial correct rejection performed at a level comparable with a single-lineup control group, suggesting that an initial identification test can impair, but not enhance, performance on a second test involving the same culprit. From a theoretical perspective, the results are consistent with the idea that the way people use memorial information when making memory decisions is flexible. Analyses of preidentification confidence ratings, obtained in a follow-up study (N=133), suggested that the effects of feedback on identification performance may have operated via differences in witnesses' metacognitive beliefs.

How should witnesses regulate the accuracy of their identification decisions: One step forward, two steps back?

“…One possibility is that the presence of the option to withhold their answer encourages participants to change what memorial evidence they evaluate in order to make a lineup decision, compared with participants required to report an answer. Similar claims have been made for lineup decisions following observations of changes in memory accuracy following feedback about a different lineup (Palmer, Brewer, & Weber, 2010), verbal description of irrelevant material (Westerman & Larsen, 1997), and induction of processing style (Perfect, Dennis, & Snell, 2007;Wyer, Perfect, & Pahl, 2010). Such observations highlight the importance of understanding the processes that underlie performance on memory tasks involving complex, compound decisions.…”

Double Exposure: The Effects of Repeated Identification Lineups on Eyewitness Accuracy

“…The witness who does not make an initial lineup identification may commit to a strategy of not choosing, perhaps informed or compelled by his or her seeming lack of success at the earlier identification (Palmer, Brewer, & Weber, 2010). A well-constructed lineup offers the protection of fillers, lineup members intentionally selected to possess physical attributes similar to the offender (unlike a mugshot search).…”

“…Previous dual-lineup studies (Hinz & Pezdek, 2001;Palmer et al, 2010;Pezdek & Blandon-Gitlin, 2005) employed culprit-absent lineups as the first ('intervening') lineup, finding a negative impact on witness accuracy at a second lineup. Previous dual-lineup studies (Hinz & Pezdek, 2001;Palmer et al, 2010;Pezdek & Blandon-Gitlin, 2005) employed culprit-absent lineups as the first ('intervening') lineup, finding a negative impact on witness accuracy at a second lineup.…”

The Effect of Feedback on Face‐Matching Accuracy

“…Such findings are useful generally for showing that person recognition is susceptible to feedback, but do not actually demonstrate improvements in identification performance. However, more recently such an improvement with feedback has also been found in an eyewitness identification paradigm (Palmer, Brewer, & Weber, 2010). In this study, observers were shown a video of a staged crime, which was followed by two photographic identity lineups.…”