Of guns and geese: a meta-analytic review of the ‘weapon focus’ literature

Abstract

Weapon focus is frequently cited as a factor in eyewitness testimony, and is broadly defined as a weapon-related decrease in performance on subsequent tests of memory for those elements of an event or visual scene concurrent to the weapon. This effect has been attributed to either (a) physiological or emotional arousal that narrows the attentional beam (arousal/threat hypothesis), or (b) the cognitive demands inherent in processing an unusual object (e.g. weapon) that is incongruent with the schema representing the visual scene (unusual item hypothesis). Meta-analytical techniques were applied to test these theories as well as to evaluate the prospect of weapon focus in real-world criminal investigations. Our findings indicated an effect of weapon presence overall (g= 0.53) that was significantly influenced by retention interval, exposure duration, and threat but unaffected by whether the event occurred in a laboratory, simulation, or real-world environment.

Keywords:

• weapon focus
• eyewitness memory
• memory
• attention
• cognition

Acknowledgements

JMF was supported by an NSERC Canada Graduate Scholarship and a Killam Predoctoral Scholarship, and would like to thank Dr. Ray Klein for comments on an earlier draft of this manuscript. KAP would also like to thank Jessica Gilbert for her research assistance. Finally, we would like to thank Dr. Kerri Pickel, Dr. Brian Bornstein and our anonymous reviewers for their feedback.