Loftus and Palmer (1974)

Loftus and Palmer (1974)

1. Experiment 1

   • What did they do?
     • 45 students
     • Shown 7 different traffic accidents
     • Asked one question: 'About how fast were the cars going when the hit each other?'
       • 5 different verbs used
         • Smashed
           • Mean speed: 40.8 mph
         • Collided
           • Mean speed: 39.3 mph
         • Bumped
           • Mean speed: 38.1 mph
         • Hit
           • Mean speed: 34.0
         • Contacted
           • Mean speed 31.8
   • The word smashed had the highest average speed whereas the word contacted had the lowest speed

2. Evaluation

   • Supporting evidence
     • Loftus et al. (1978)
       • Two groups
         • One shown a red Datsun pulling up to a 'STOP' sign
         • Other group shown a red Datsun pulling up to a 'YIELD' sign
         • Half of each group had the question 'Did another car pass the red Datsun while at the 'YIELD' sign?' Other half asked the question saying the 'STOP' sign.
           • Then shown pairs of slides and had to identify the correct sequence
             • 75% of participants with consistent questions chose the correct slides
             • 41% of participants with inconsistent questions chose the correct slides
   • Acquisition or retrieval?
     • Bekerian and Bowers (1983)
       • Replicated Loftus et al. (1978)
         • Gave participants the slide in the original order
           • Recall now same for consistent and misleading groups
             • Participants memories still intact, therefore misleading questions (post-event information) would appear to affect the retrieval of memories, rather than their storage
   • EWT in real life
     • Yuille and Cutshall (1986)
       • Interviewed 13 people who had witnessed a bank robbery in Canada 4 months after the crime
         • Interview included 2 misleading questions
           • Witnesses still provided accurate information
             • Suggesting post-event information may not affect the memory in real life EWT

3. Investigated misleading information in eye witness testimony (EWT)

   • Found misleading information does have an effect on recall

4. Experiment 2

   • Smashed gave higher speed and more likely to see broken glass
   • What did they do?
     • New set of participants that were put into 3 groups
       • Group 1 had the verb smashed
       • Group 2 had the verb hit
       • Group 3 were the control group - were not asked about the speed of the cars
     • 'Did you see any broken glass?'
       • Smashed
         • Yes: 16
         • No: 34
       • Control
         • Yes: 6
         • No: 44
       • Hit
         • Yes: 7
         • No: 43