The influence of alcohol and weapon presence on eyewitness memory and confidence

摘要

In this quasi-experimental field study, bar drinkers (0.00-0.23% blood alcohol content) viewed a photographic sequence in which a male took a laptop from a helpdesk assistant, either on loan or at gunpoint. Following a brief retention period, participants answered 20 multiple-choice questions about the male, his actions, and details of the scene, then attempted to identify him from a simultaneous target-present or target-absent line-up. Alcohol was associated with a reduction in correct identifications and an increase in false identifications. Surprisingly, the presence of a weapon in the scene enhanced identification accuracy, though wider scene memory was not influenced by alcohol or the weapon. Findings offer some support for the view that alcohol restricts face encoding, perhaps through the narrowing of attention to salient external features (e.g., hair). We also suggest that curiosity about mock-crime perpetrators may produce weapon focus reversals, although the factors that might elicit such curiosity remain unclear.