Eyewitness metamemory predicts identification performance in biased and unbiased line‐ups

Abstract

Purpose. Distinguishing accurate from inaccurate identifications is a challenging issue in the criminal justice system, especially for biased police line-ups. That is because biased line-ups undermine the diagnostic value of accuracy post-dictors such as confidence and decision time. Here, we aimed to test general and eyewitness-specific self-ratings of memory capacity as potential estimators of identification performance that are unaffected by line-up bias.Methods. Participants (N = 744) completed a metamemory assessment consisting of the Multifactorial Metamemory Questionnaire and the Eyewitness Metamemory Scale and took part in a standard eyewitness paradigm. Following the presentation of a mockcrime video, they viewed either biased or unbiased line-ups.Results. Self-ratings of discontentment with eyewitness memory ability were indicative of identification accuracy for both biased and unbiased line-ups. Participants who scored low on eyewitness metamemory factors also displayed a stronger confidence-accuracy calibration than those who scored high.Conclusions. These results suggest a promising role for self-ratings of memory capacity in the evaluation of eyewitness identifications, while also advancing theory on selfassessments for different memory systems.Eyewitnesses play a major role in the criminal justice system, especially in cases lacking other physical evidence. In many jurisdictions, suspects are more likely to be prosecuted if an eyewitness identifies them as the perpetrator of a crime. However, as with other types of evidence, eyewitness identifications can be in error or contaminated (Wixted, Mickes, This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

A validation of the two-high threshold eyewitness identification model by reanalyzing published data

“…47,48 ] to obtain an estimate of the innocent-suspect identifications in culprit-absent lineups. However, it is well known that real-world lineups are often not perfectly fair and there is strong evidence of a biased selection of suspects in unfair lineups [e.g., [56][57][58] ]. If the 2-HT eyewitness identification model is valid, then the biased selection of suspects in unfair lineups should be sensitively reflected in parameter b.…”

Eyewitness Decision Processes: A Valid Reflector Variable

“…Both are consistently found to predict eyewitness accuracy, though there is room for improvement. Research has identified a few other potential reflector variables, but more research is needed on these: memory for fillers (Charman & Cahill, 2012), metamemory (Saraiva et al, 2020a;2020b), response bias (Baldassari, Kantner, & Lindsay, 2019), and face identification ability (Bindemann et al, 2012). We were particularly interested in the role of decision processes.…”

Comments on the use of mathematical models in eyewitness identification research

“…For example, where an innocent suspect stands out in a lineup, eyewitnesses tend to be overconfident and as a result, high-confidence identifications become less accurate and leaving the usage of high-confidence ratings as an indicator of probative value within courts premature (Berkowitz, Garrett, Fenn, & Loftus, 2022). Saraiva, van Boeijen, Hope, Horselenberg, Sauerland, & van Koppen (2020) suggest that eyewitnesses may use a potentially misleading heuristic-perceived task difficulty-as a proxy for underlying discriminability, especially where fillers become implausible options or where memory self-efficacy is rated as very high or very low. Thus, it seems that, as true Bayesian observers, eyewitnesses apply all available information during their eyewitness identification decisions, including metacognitive information not currently included in existing SDT models of eyewitness memory.…”