Loftus Weapon Focus

Experiment One

The aim of the study was to investigate and assess evidence for weapon focus.

The participants were 36 students from Washington University

The method was a Laboratory Experiment with an Independant Measures Design

The participants viewed a series of 18 slides of people in a queue for a restaurant cashier. The control condition saw "person B" holding a cheque, while the weapon condition saw "person B" holding a gun.

Eye movements were recorded with a corneal reflection device. A 15 minute interval was given between viewing the slides and the questionnaire. 

The questionnaire was a 20-item multiple choice questionnaire, including 7 items about "person B", e.g. "What was the colour of B's coat?" 

Next, they were given a "line-up" of 12 photos to test identification of "person B"

Experiment Two

The aim of the study was to investigate and assess evidence for weapon focus.

The participants were 80 Psychology students from Washington University

The method was a Laboratory Experiment with an Independant Measures Design

40 were in the control condition (cheque), 40 were in the weapon condition (gun). Same slide presentation as experiment 1. 

After a 15 minute interval after seeing the slides, the participants were given a 7 item multiple choice test of items relating to "person B", followed by a "line-up" identification test of 12 photos.

Results

Experiment One - No significant difference found between the conditions in accuracy of questionnaire responses overall, or on the 7 items relating to "person B". Eye movement data showed a significant difference however, with the weapon condition showing longer eye fixations than the control condition. The "line-up" data showed that the control group's identification of "person B" was slightly more accurate than the weapon condition (marginally significant).

Experiment Two - Questionnaire responses and line-up data analysis revealed that the weapon condition participants were significantly less accurate than the control condition.