Eyewitness testimony: Misleading information

• What are the three factors that affect eye witness testimony?

  1. misleading information
  2. leading questions
  3. post event discussion
• What is misleading information?

  Incorrect information given to an eyewitness usually after the event
• What are leading questions?

  A question which suggests a certain answer, e.g. Was the knife in his left hand?
• What is post event discussion?

  When there is more than one witness to an event and they discuss what they have seen
• What did Loftus and Palmer conduct a study on?

  Misleading information
• What was Loftus and Palmer's procedure?

  45 students watched clips of a car accident and were asked questions about the accident, including the critical (leading) question: 'About how fast were the cars going when they hit/contacted/bumped/collided/smashed into each other?'
• What were Loftus and Palmer's findings?

  • Word 'contacted' mean speed = 31.8mph
  • word 'smashed' mean speed = 40.5 mph
• Why do leading questions affect EWT?

  • Response bias explanation: wording of a question has no real affect on the memory but influences how they decide to answer (e.g. smashed produces higher speed)
  • Substitution bias: Loftus and Palmer- wording of a question changes memory, smashed condition more likely to remember broken glass. The critical verb altered their memory of the incident.
• Who conducted a study into post-event discussion?

  Gabbert et al
• what was Gabbert et al's procedure?

  Pair of ppts watch a video of a crime from a different pov. Then discuss what they saw before test of recall.
• What were Gabbert et al's findings?

  • 71% of ppts mistakenly recalled aspects of the event they did not see but discussed in post-event discussion
  • The same figure in a control group where there was no post event discussion was 0%
• Why does post-event discussion affect EWT?

  • Memory contamination: combine (mis)information with their own memory
  • Memory conformity: witness go along with each other to win social approval or because they believe the other witness' are right and they are wrong
• Strength: Real world application

  P- Real world application in the criminal justice system

  E- Consequences of inaccurate EWT are serious. Loftus said police officers should be careful in phrasing questions

  E- Psychologists are sometimes expert witnesses in trials to explain limits of EWT

  L- Therefore research can improve the legal system
• Counterpoint:

  • Loftus and Palmer showed their participants film clips, which is a very different situation and less stressful than real life
  • Ppts are less concerned about the accuracy as the effect of their responses in a lab study will have no consequences
  • Therefore, EWT might be more accurate and reliable in real life when the consequences are real.
• Limitation: Evidence against substitution

  P- Evidence challenging substitution explanation

  E- Sutherland and Hayne ppts recalled central details of an event than peripheral ones, even when asked misleading questions

  E- Possibly due to their attention focused on the central features, these memories were resistant to misleading information

  L- The original memory of the event survived and was not distorted, which is not predicted by the substitution explanation.
• Limitation: evidence challenging memory conformity

  P- Another limitation of the memory conformity explanation is evidence that post-event discussion actually alters EWT

  E- Skagerberg and Wright showed their ppts film clips. These were two versions. Ppts discussed the clips in pairs, each having seen different versions

  E- They often did not report what they had seen in the clips or what they had heard from the co-witness, but a blend of the two

  L- This suggests that the memory itself is distorted through contamination by misleading post-event discussion, rather than the result of memory conformity.
• Evaluations- demand characteristics

  P- Lab studies have identified misleading information as a cause of inaccurate EWT, partly by being able to control variables.

  E- But Zaragoza and McCloskey argue that many answers given by ppts in lab studies are due to demand characteristics

  E- Ppts want to be helpful and not let the researcher down, so they guess when they are being asked a question, they don't know the answer to

  L- This questions the validity of misleading information as a cause of inaccurate EWT.