Long Retention Intervals Impair the Confidence-Accuracy Relationship for Eyewitness Recall

A growing body of research suggests that confidence judgements can provide a useful indicator of memory accuracy under some conditions. One factor known to affect eyewitness accuracy, yet rarely examined in the confidence-accuracy literature, is retention interval. Using calibration analyses, we investigated how retention interval affects the confidence-accuracy relationship for eyewitness recall. In total, 611 adults watched a mock crime video and completed a cued-recall test either immediately, after 1 week, or after 1 month. Long (1 month) delays led to lower memory accuracy, lower confidence judgements, and impaired the confidence-accuracy relationship compared to shorter (immediate and 1 week) delays. Long-delay participants who reported very high levels of confidence tended to be over-confident in the accuracy of their memories compared to other participants. Self-rated memory ability, however, did not predict eyewitness confidence or the confidence-accuracy relationship. We discuss the findings in relation to cue-utilization theory and a retrieval-fluency account.

Providing Eyewitness Confidence Judgements During Versus After Eyewitness Interviews Does Not Affect the Confidence-Accuracy Relationship

Recent studies suggest that highly confident eyewitnesses are likely to provide highly accurate identification evidence, at least in some conditions. Yet few studies have investigated the confidence-accuracy relationship in witness interviews or exactly when confidence judgements should be taken. Across three experiments, 831 adults answered questions about a mock crime and rated their confidence in each response. Participants gave their confidence immediately after each response or at the end of the memory test. The timing of the confidence judgement did not affect the confidence-accuracy relationship, and the confidence-accuracy relationship remained strong even when participants encoded the event under poor visibility conditions. When participants were unknowingly exposed to misinformation, however, the confidence-accuracy relationship was substantially weakened—participants became highly over-confident in the accuracy of their memories. These findings help to refine the parameters in which witness confidence serves as a useful indicator of memory accuracy.

Eyewitness identification performance is not affected by time-of-day optimality

The circadian rhythm regulates arousal levels throughout the day and determines optimal periods for engaging in mental activities. Individuals differ in the time of day at which they reach their peak: Morning-type individuals are at their best in the morning and evening types perform better in the evening. Performance in recall and recognition of non-facial stimuli is generally superior at an individual’s circadian peak. In two studies (Ns = 103 and 324), we tested the effect of time-of-testing optimality on eyewitness identification performance. Morning- and evening-type participants viewed stimulus films depicting staged crimes and made identification decisions from target-present and target-absent lineups either at their optimal or non-optimal time-of-day. We expected that participants would make more accurate identification decisions and that the confidence-accuracy and decision time-accuracy relationships would be stronger at optimal compared to non-optimal time of day. In Experiment 1, identification accuracy was unexpectedly superior at non-optimal compared to optimal time of day in target-present lineups. In Experiment 2, identification accuracy did not differ between the optimal and non-optimal time of day. Contrary to our expectations, confidence-accuracy relationship was generally stronger at non-optimal compared to optimal time of day. In line with our predictions, non-optimal testing eliminated decision-time-accuracy relationship in Experiment 1.