Long retention intervals impair the confidence–accuracy relationship for eyewitness recall.

A growing body of research suggests that confidence judgments 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 judgments, 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 overconfident 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.