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.