Accuracy and confidence in person identification: The relationship is strong when witnessing conditions vary widely

We hypothesized that both accuracy and confidence in suspect identifications depend, in part, on participants' ability to identify the target, and that both accuracy and confidence therefore tend to be higher under conditions that lead to good memory for the target than under conditions that lead to poor memory for the target. Furthermore, we hypothesized that a substantial correlation between accuracy and confidence will be observed if, because of variations in conditions, there is considerable variability across participants in ability to identify the target. Consistent with these hypotheses, manipulations that affected accuracy also affected confidence in the same direction,and when data were collapsed across conditions, the accuracy-confidence correlation was substantial (mean r = .59).