EWT: Misleading information

• Eyewitness Testimony (EWT)

  =  the evidence given in a court or in police investigations by someone who has witnessed a crime or accident.
• Importance of EWT

  EWT is an important area of study in cognitive psychology and memory studies.

  EWT is used as evidence in criminal trails all over the world and juries tend to pay extra attention to EWT and see them as trustworthy, reliable and convincing.

  BUT research has shown that EWT can be affected by many psychological factors.
• What is misleading information in the context of eyewitness testimony?


  It is supplying information that may alter a witness’ memory for a crime.
• What are the two examples of misleading information?

  Leading questions and post-event discussion.
• What is a leading question?


  A leading question suggests to the witness what answer is desired or leads them to that answer.
• How do leading questions affect eyewitness testimony (EWT)?


  They can influence the kind of answer given by the witness.
• What is the response-bias explanation regarding leading questions?


  It suggests that the wording of a question influences the kind of answer given but not the eyewitness memory itself.
• What is the substitution explanation in relation to leading questions?


  It posits that the wording of a question affects eyewitness memory and distorts its accuracy.
• What are the key differences between the response-bias explanation and the substitution explanation regarding leading questions?


  • Response-bias explanation: Wording influences the answer given, not the memory.
  • Substitution explanation: Wording affects and distorts the original memory.
• Loftus and Palmer ( 1974)

  To see the effect of leading questions on memory of an event, in order to see if EWT is reliable.

  Procedure

  45 participants (students) watched film clips of car accidents and then answer questions about speed

  -5 groups of participants

  -Each group given a different verb in the question: hit/contacted/ bumped/ collided/smashed

  • estimations of speed (mph) were recorded
  • participants were also asked to describe the event in their own words
• Results and conclusions

  = the leading questions (verb) biased eyewitness recall of an event. 

  The verb “smashed” suggested a faster speed of the car than “contacted”.
• Study 2 

  New set of participants

  3 groups

  Shown film of car accident lasting 1 minute

  Asked questions about speed

  Participants asked to come back one week later

  Asked 10 questions about the accident including

  Study 2 Results

  = this shows that the leading question did change the actual memory

   a participant had for an event
• Study 2 Conclusion

  Use of verb ‘smashed’ distorts memory of an event – this supports the substitution explanation. Pts hearing this word are more likely to remember seeing broken glass.
• 2. Post-event discussion

  Why do post-event discussion affect EWT?

  Memory contamination= when co-witness 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
• KEY STUDY 2: Gabbert et al. (2003)

  Procedure: 

  Paired pts watched a video of the same crime, but filmed so each of the pt could see elements in the event that the other could not

  Both pts discussed what they had seen on the video before individually completing a test of recall

  Findings and conclusions:

  71% of the pts mistakenly recalled aspects of the events that they did not see but had picked up in the post-event discussion

  In a control group, where there was no discussion, there were no errors
• Evaluation of Gabbert and al. (A03) - {1 of 2}

  Issue with ecological validity. The participants in the co-witness condition witnessed different perspectives of the same crime, as would typically be the case in real life crimes. However, like Loftus and Palmer, these witnesses knew they were taking part in an experiment and were more likely to have paid close attention to the details of the video clip. Therefore, these results do not reflect everyday examples of crime, where witnesses may be exposed to less information.
• Evaluation of Gabbert and al. (A03) - {2 of 2}

  Gabbert et al. tested two different populations, university students and older adults and found little difference between these two conditions. Therefore her results provide good population validity and allow us to conclude that post-even discussion affects younger and older adults in a similar way.