Date of Graduation

5-2012

Document Type

Thesis

Degree Name

Master of Arts in Psychology (MA)

Degree Level

Graduate

Department

Psychological Science

Advisor/Mentor

Lampinen, James M.

Committee Member

Feldner, Matthew T.

Second Committee Member

Beike, Denise R.

Keywords

Psychology; Arousal; Eyewitness; Focus; Law; Memory; Weapon

Abstract

When an eyewitness suffers an impairment of memory for a criminal's face because the criminal used a weapon during the commission of the crime, this impairment is called the weapon focus effect. Literature provides two explanations for how this effect arises: some implicate the narrowing of attentional cues to the weapon during the commission of a crime because arousal of the victim increases, while others claim that the weapon is merely a novel object in most everyday contexts, and novel objects demand more attention than contextually appropriate ones. The current study employed a simulated crime paradigm taking place in a bar where a criminal brandished either a drinking glass (normal object), a rubber chicken (novel object), or a gun (weapon). Timing of the object's presentation was also manipulated such that it was visible before, after, or during the time when the culprit's face was visible. Target-present and target-absent lineups, cued-recall questions, and retrospective identification confidence questions were administered. The weapon focus effect was found on diagnosticity ratios of lineup selections when objects were presented after the face such that the glass was more diagnostic of suspect guilt than the gun or the chicken. When objects were presented in tandem with the face, the glass was only more diagnostic of guilt than the gun. Eyewitness confidence suffered most when the chicken was seen. Implications for current theories of weapon focus and public policy are discussed.

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