Misleading information affecting eyewitness testimony

• Loftus and Palmer (1974) Experiment 1

  Interested in the accuracy of memory after witnessing a car accident, in particular to see if leading questions distorted the accuracy of an eyewitness' immediate recall
• Loftus and Palmer Experiment 1 Procedure

  1. Showed 45 students 7 films of different traffic accidents

  2. After each film, participants given a questionnaire to describe the accident and answer specific questions

  3. One critical question asked about the speed of the cars, with different verb variations (hit, smashed, collided, bumped, contacted)

  4. Mean speed estimate calculated for each group
• The group given the word 'smashed' estimated a higher speed (about 41mph), while the group given 'contacted' estimated the lowest speed (about 30mph)
• Loftus' research suggests that EWT was generally inaccurate and unreliable, as the form of questioning can have a significant effect on a witness' answer
• However, this was a laboratory study and may not reflect the recall of those who witness real life car crashes
• Loftus and Palmer Experiment 2: Broken glass

  Investigated whether leading questions bias a participant's response or actually cause information to be altered before it is stored
• Loftus and Palmer Experiment 2 Procedure

  1. 150 new participants divided into 3 groups and shown a film of a car accident

  2. After 1 week, participants asked 10 questions, including one critical question: "Did you see any broken glass?"

  3. No broken glass in the film, but those who had the 'smashed' question were more likely to say yes, compared to the 'hit' or control group
• Experiment 2 Conclusion. This suggests that the leading question did change the actual memory a participant had for the event
• Conformity effect


  Witnesses go along with each other for social approval or they think other witnesses are right and they are wrong
• Gabbert et al. (2003) Procedure


  1. Studied participants in pairs, both watched a video of the same crime but from different angles

  2. Participants then discussed what they had seen and completed a recall test

  3. 71% of participants mistakenly recalled aspects of the event that they did not see in the video but had picked up in the discussion
• Repeat Interviewing


  • Each time an eyewitness is interviewed there is the possibility that comments from the interviewer will become incorporated into their recollection of events
  • Interviewer may also use leading questions
  • Especially the case when children are being interviewed about a crime
• • One criticism of research investigating the accuracy of eyewitness evidence is the individual difference of witnesses
  • Schater et al the elderly people have difficulty remembering the source of their information even though they’re memory for the information itself is unimpaired
  • Consequently, they become more prone to the effect of misleading information
  • Individual differences in particular age are important factor when examining the reliability of EW accounts
• • One strength of research investigating EW testimony is application of the findings for the criminal justice system
  • Recent DNA exoneration cases have shown that mistaken EW identification was the largest factor contributing to the conviction of innocent people.
  • Matters because the research can help ensure that innocent people are not convicted of crimes they did not commit, on the basis of faulty EW evidence
• • One criticism of research into the effects of misleading information on EWT, such as Loftus and Palmer research is the lack of ecological validity and mundane realism
  • Lab experiments do not represent real life crime/accidents
  • Therefore, participants may not take the experiments seriously and they may not be emotionally aroused in the same way they would be a real crime
  • matters - lacks Ecological validity and don’t apply to real life crimes/accidents
• • limitation of lab studies into the effects of misleading information on EWT is the possibility of demand characteristics
  • Participants may guess the aim of the study and give responses that they think the investigator wants to receive
  • For example, if participants are asked, did you see any broken glass? They may answer because they want to be more helpful.
  • This challenges the validity of EWT research because the studies are not actually measuring the accuracy of it but instead of the answer the participants thinks researchers want to hear