Loftus Et Al

Loftus Et Al

1. Aim

   • To provide support for the Weapons focus effect when witnessing a crime

2. Procedure

   • Lab experiment
     • Independent measures
   • 36 students from the University of Washington
     • Aged 18-31
       • Advertisement, paid $3.50
       • Others psychology students participating for extra credits
   • Shown 18 slides of a seriesof events in a Taco restaurant
     • For both groups the slides were the same except for one slide
     • The slide was the independent variable
     • In the control group the second person in the queue hands the cashier a cheque
     • In the experimental group the same person pulls a gun on the cashier
     • DV was recognition of that person, it was measured by a 20 item multiple choice questionnaire
     • Participants were also shown 12 line-up photos in random sequence and asked to rate how confident they were of their identification using a 6 point rating scale

3. Results

   • Answers to the questionnaire about the slide show showed no significant difference between the 2 groups
   • In the control condition 38.9% made a correct identification
   • In the experimental condition it was only 11.1%
   • 3.72 secs eye fixation on the gun
   • 2.44 secs eye fixation on the cheque

4. Conclusion

   • The participants spent longer looking at the weapon and therefore had more difficulty in picking the suspect from the line-up, this was confirmed in a second experiment with 80 participants