A perpetrator's accent impairs witnesses' memory for physical appearance.

Sometimes witnesses to crimes must remember both a perpetrator's appearance and voice. Drawing upon multiple resource theory as well as previous findings that processing foreign-accented speech is more demanding than processing unaccented speech, we hypothesized that a perpetrator's accent can impair memory for his or her appearance. In Experiment 1, we used a secondary visual search task to demonstrate that processing an accented versus unaccented message demands more cognitive resources. In two additional experiments, we extended that result by showing that witnesses trying to encode information spoken by a perpetrator with an accent rather than no accent provided poorer physical descriptions of him and identified his voice less accurately. We also found that witnesses who heard a more versus less detailed message reported fewer correct details about the perpetrator's appearance (Experiment 2), and a more rather than less threatening message led to less accurate descriptions (Experiment 3).