EWT

• Eyewitness Testimony

  remembering details of events and crimes observed
• Misleading Information

  incorrect info given to the eyewitness after the event:

  • leading questions
  • post-event discussion
• Leading Questions Research:

  Loftus and Palmer

  • 45 participants watch a car accident video and answer a questionnaire
  • "How fast were the cars going when they - each other?"
  • 5 groups with different verbs - hit, contacted, bumped, collided, smashed
• Leading Questions finding

  Loftus and Palmer

  • mean speed calculated was highest with 'smashed' (40.5) than with 'contacted' (31.8)
  • leading questions changed the recall of the event
• Why do Leading Questions affect EWT?

  Response Bias - wording influences the answer but doesn't affect the memory

  Substitution - question alters the memory of an event
• Post-Event Discussion Research

  Gabbert et al:

  • participants in pairs viewed the same crime from different angles then discussed what they saw before completing a recall test
• Post-Event Discussion Findings

  Found 71% of participants recalled aspects that they didn't see but were told in the discussion (0% for control group)
• Why does PED affect EWT?

  Memory contamination - combine info with their own memories

  Memory conformity - go along with other witnesses to gain social approval or to be 'right'
• Strength of misleading info

  The consequences of inaccurate EWT in the real world are serious so research has enabled the cognitive interview, which provides more accurate info
• Weakness of misleading info

  Loftus and Palmer's study was in a lab and so doesn't show real-life situations.

  Yuille and Cutshall found that witnesses to a armed robbery gave accurate reports despite leading questions
• Anxiety

  State of emotional and physical arousal
• Negative effect of anxiety research

  Johnson and Scott

  • participants in a waiting room experienced one of two conditions
  • casual convo + man holding pen with greasy hands
  • heated argument + man holding knife with bloody hands
• Negative effect of anxiety findings

  Participants were asked to choose the man from 50 photos

  • Casual + pen had 49% accuracy
  • Heated + knife had 33% accuracy
  • Led to development of 'weapon focus'
• Positive effect of anxiety research

  Yuille and Cutshall

  • real-life shooting in Canada with 21 witnesses - 13 participated
  • interviwed 4-5 months after the shooting and compared with original police interviews
  • EWT determined by details recalled
  • Participants asked about stress levels during and after the shooting
• Positive effect of anxiety findings

  Witnesses were very accurate and there was little change in the amount or accuracy recalled

  • those with the highest levels of stress were the most accurate (88% compared to 75% less stressed)
• Strength of positive effect of anxiety

  Christianson and Hubinette found that direct witnesses to a bank robbery in Sweden were the most accurate recallers
• Weakness of anxiety

  Studies have methodological issues as the researcher's couldn't control what happened to participants in the intervening time e.g. post-event discussion
• Cognitive Interview

  Fisher and Geiselman recommeded that police use psychological insights to improve EWT accuracy
• Techniques in Cognitive Interview:


  • report everything - all details without editing anything
  • reinstate the context - mentally recreated the environment of the incident
  • reverse the order - recalled in a different order - prevents dishonesty and expectations
  • change the perspective - asked to recall event from other people's point of view
• Application of CI to psychology

  Retrieval failure - report everything, reinstate context relate to dependent forgetting

  Schema - reverse order , change perspective help disrupt schema
• Enhanced Cognitive Interview (ECI)

  Fisher et al added elements that focus on social dynamics between interviewer and participant

  • reduce anxiety
  • speak slowly
  • open-ended questions
  • no distractions
  • establish rapport for more recall
• Strength of CI

  A meta analysis of 55 studies showed that the ECI was better than a standard interview
• Weakness of CI

  Kebbell and Wagstaff say the CI is time-consuming for police officers and requires special training to do it right