eyewitness testimony: misleading information

• ao1: Loftus and Palmer (1974) Leading questions

  PROCEDURE:

  • 45 participants (students) watched film clips of car accidents and then answered questions about speed. Critical question: 'About how fast were the cars going when they hit each other?
  • Five groups of participants, each given a different verb in the critical question hit, contacted, bumped, collided or smashed.

  FINDINGS:

  • The verb contacted produced a mean estimated speed of 31.8 mph. For the verb 'smashed, the mean was 40.5 mph
  • The leading question (verb) biased eyewitness recall of an event. The verb 'smashed suggested a faster speed of the car than 'contacted’.
• ao1: Why do leading questions affect EWT?

  Response-bias explanation:

  • Wording of a question has no enduring effect on an eyewitness's memory of an event, but influences the kind of answer given.

  Substitution explanation:

  • Wording of a question does affect eyewitness memory, it interferes with the original memory, distorting its accuracy
• ao1: Gabbert et al. (2003) Post-event discussion

  PROCEDURE:

  • Paired participants watched a video of the same crime, but filmed so each participant could see elements in the event that the other could not
  • Both participants discussed what they had seen on the video before individually completing a test of recall

  FINDINGS:

  • 71% of participants wrongly recalled aspects of the event they did not see in the video but had heard in the discussion
  • Control group - there was no discussion and no subsequent errors
  • This was evidence of memory conformity
• ao1: Why does post-event information affect EWT?

  Memory contamination:

  • When co-witnesses discuss a crime, they mix (mis)information from other witnesses with their own memories.

  Memory conformity:

  • Witnesses go along with each other to win social approval or because they believe the other witnesses are right.
• ao3: One strength is real-world applications in the criminal justice system.

  • The consequences of inaccurate EWT are serious. Loftus (1975) argues police officers should be careful in phrasing questions to witnesses because of distorting effects.
  • Psychologists are sometimes expert witnesses in trials and explain limits of EWT to juries.
  • Therefore psychologists can improve how the legal system works and protect the innocent from faulty convictions based on unreliable EWT
• ao3: COUNTERPOINT TO REAL WORLD APPLICATIONS

  • Loftus and Palmer showed film clips - a different experience from a real event (less stress). Participants are also less concerned about the effect of their responses in a lab study (Foster et al 1994).
  • Therefore researchers may be too pessimistic about the effects of misleading information - EWT may be more reliable than studies suggest
• ao3: One limitation of the substitution explanation is evidence challenging it.

  • Sutherland and Hayne (2001) found their participants recalled central details of an event better than peripheral ones, even when asked misleading questions.
  • This is presumably because their attention was focused on the central features and these memories were relatively resistant to misleading information.
  • Therefore the original memory of the event survived and was not distorted, which is not predicted by the substitution explanation.
• ao3: Another limitation is that evidence does not support memory conformity.

  • Skagerberg and Wright's (2008) participants discussed film clips they had seen (in one version the mugger had dark brown hair and the other light brown).
  • The participants recalled a 'blend' of what they had seen and what they had heard from their co-witness, rather than one or the other (e.g. said hair was 'medium brown').
  • This suggests that the memory itself is distorted through contamination by post-event discussion and is not the result of memory conformity