Eyewitness Testimony

• MISLEADING INFORMATION

  Lotus and Palmer (1974) 1:

  • 45 participants shown seven films of different traffic accidents
  • Given a questionnaire after each film
  • Critical question “how fast were the cars going when they … each other?”
  • Used verbs: hit, collided, bumped, smashed, contacted.
  • Smashed was the highest and contacted was the lowest.
• MISLEADING INFORMATION - leading questions

  Loftus and Palmer (1974) 2:

  • 150 student participants shown a film about a traffic accident
  • Divided into three groups
  • Asked to return a week later
  • 10 questions - one critical question “did you see any broken glass”
  • The word smashed resulted in the highest number saying they saw broken glass
• Response bias - leading questions affect recall because they affect the answers given but do not actually affect the memory of the event.
• Substitution explanation - leading questions has affected the recall of the memory and distorts the memory of the event.
• POST EVENT DISCUSSION

  Gabbert et al (2003)

  • 60 university students and 60 olders
  • Two video clips, each 90 seconds with the same sequence but a different camera angle
  • Showed a girl returning a book to an office, but the other angle showed her stealing a £10 note
  • Half were given the time to discuss what they had seen with the opposite perspective
  • They all then had to complete a questionnaire on what they saw
  • 71% who discussed reported info they had not seen. 60% reported the girl guilty of a crime they hadn't seen
  • Shows that post event discussion does affect memory
• POST EVENT DISCUSSION

  Hope et al (2008)

  • 96 university students watched the same videos
  • 24 were then allowed to complete a questionnaire individually, the remaining were paired to someone who had seen a different perspective.
  • Two critical questions which one could only be answered form one perspective
  • Those who spoke with others were susceptible of misinformation and produced less accurate accounts.
• Memory contamination - memory is changed by the new information being mixed with the memory of the original event
• Memory conformity - PED doesn’t affect the memory but people change their answers to confirm to others for social approval
• STRENGTHS

  Internal validity - highly controlled conditions. L+P controlled extraneous variables by showing the exact same clip with the exact same time. Can establish cause and effect .

  
  

  Practical application - police avoid using cognitive interview technique and importance of not allowing post even discussion to produce accurate eye witness testimony
• LIMITATIONS

  Ecological validity - used an artificial event and told participants to pay attention, this wouldn’t have happened in real life.

  Johnson and Johnson - heightened anxiety when witnessing an event

  Population validity - Loftus and Palmer only used university students, Anastasi and Rhodes (2006) found that younger people have a more accurate recall so those who did have a better recall aren’t representative of all age groups. Can’t be generalised
• Anxiety

  Yerkes and Dodsons Law suggests that performance is related to arousal. Too much arousal is interpreted as stress and anxiety.
• Anxiety

  Tunnel theory: suggests that if there is a weapon involved in a crime it creates anxiety. Our attention focuses on the weapon, making our recall poor as we are not attending to all of the available sensory information.
• Johnson and Scott (1976)

  Aim: if levels of anxiety can affect recall.

  Method: participants listening to conversation in a lab.

  1. Low anxiety - lowkey discussion about equipment failure. Person emerged holding a pen with grease on his hands
  2. High anxiety - heated hostile exchange. Sound of breaking glass and crashing chairs. Man emerged holding a paper knife covered in blood.

  Results: Participants who witnessed the more violent science were less accurate in their recall. 49% in the low anxiety and 33% in the high anxiety gave correct identifications.
• Anxiety

  Flight or fight: when you’re in a stressful situation your body either chooses to fight the situation or run away.
• Yuille and Cutshall (1986)

  Aim: if anxiety would affect memory recall.

  Method: Real life shooting, gun shop in Canada, 13 witnesses, unarmed thief, storeowner shoots the thief dead. Participants interviewed 4-5 months later, recall was compared, stress levels on a 7 likert scale.

  Results: Witnesses accuracy of recall didn't seem to be affected, they were resistant to leading questions, stuck to their original impressions. Those who were most distressed were most accurate in recall.

  Conclusion: high anxiety didn’t impair memory recall, enhanced accuracy.