Factors affecting the accuracy of eyewitness testimony: misleading information including leading questions and post event discussion

Leading Questions:

• Loftus and Palmer 1974 arranged for participants (students) to watch film clips of car accidents and then gave them questions about the accident. In the critical question (leading question) paricipants were asked to describe how fast the cars were travelling. There were five groups and each group had a different verb in the leading question: hit, contacted, bumped, collided or smashed. The mean estimated speed was calculated for each group. Contacted = 31.8mph while smashed was 40.5mph. this shows that the leading question biased the result.
• the response bias explanation suggessts that the wording of the question has no real affect on their memory of the event, but influences how they decide to answer. When a participant has a question with the word smashed in it, it encourage them to choose a higher speed.
• Loftus and Palmer did another experiment at the same time to support the substitution explanation (the wording of the question actually alters the participants memory of events). This is because those who heard the word smashed were more likely to later report seeing broken glass in the video (there was none) than those who heard hit.
  

Post event discussion:

• when witnesses to a crime discuss it with each other, this can contaminate their memory of events / eyewitness testimony. This is due to them comining (mis)information from other witnesses with their own version of events.
• Gabbert et al 2003 studied participants in pairs. Each participant watched a video of the same crime, but filmed from different points of view - meaning…