Eyewitness testimony

• What is eyewitness testimony?


  The ability of people to remember the details of events, such as accidents and crimes, which they themselves have observed.
• What factors can affect eyewitness testimony?

  • Stress
  • Setting/how far you were from the event
  • Misleading information
  • Leading questions
• What is misleading information?


  Incorrect information given to the eyewitness usually after the event (often called post-event information). Can take many forms, including leading questions and post-event discussion between co-witnesses and/or other people.
• What are leading questions?


  Questions that are phrased in a way which suggests a certain answer e.g. "Was the knife in his left hand?"
• How did Loftus and Palmer investigate the effect of leading questions?

  45 students watched clips of car accidents. They were then asked questions about the clips with the critical question being about speed. They were split into 5 groups who got 5 different phrasings of the question "How fast were the cars going when they ____ each other? Each group had a different verb fill the gap: contacted, hit, bumped, collided, smashed. Mean estimates of speed in mph for each group were: 32, 34, 38, 39 and 41. The leading question biased the eyewitness recall of the event.
• What is the response-bias explanation?


  The wording does not influence the memory - however it influences their choice of what they think happened (e.g. leading questions).
• What is the substitution explanation?


  When the wording of the question actually changes the memory of the participant (e.g. Loftus and Palmer).
• What is the source monitoring theory?

  That memories of the events by eyewitness testimony's are usually distorted. The eyewitness can recall information about the event (both accurate and inaccurate) but they can't recall where it came from. Was it from their own memory of the event or did they hear it from someone else? This is known as source confusion.
• What is the conformity theory?

  Argues that eyewitness memories are not actually distorted by post-event discussion. Instead, the eyewitness recall appears to change only because they go along with the accounts of co-witnesses. They do this either to win social approval or because they genuinely believe other witnesses are right and they are wrong. Supported by Gobbart et al. Showed pairs of participants clips of a crime from different viewpoints and found 71% of participants recalled aspects of the crime they had not seen but had picked up in discussion.
• Evaluation of Loftus and Palmer:

  • Sample may not be representative of the population. Used students which might reduce their ability to estimate speed. Should be cautious about generalising findings.
  • Used a standardised procedure. Saw the same video and asked the same questions. Can be replicated to establish reliability.
  • Lacked ecological validity - conducted in laboratory. In a real crash, may have less clear view so less accurate in judgements. Findings may not be representative of real life.