eye witness testimony

• misleading information: wording of a question that may imply a certain answer

  Loftus and Palmer (1974): made participants watch a film clip of a car accident - changed wording of questions to leading words (how fast was the car going when it smashed, crashed, hit, collided) - changed verb of critical question

  • findings: higher estimated speed with more violent verbs - showing that leading questions influence recollection of events
• response-bias explanation: suggests wording of question has no effect on memory, but on how you decide to answer

  substitution explanation: wording does affect memory

  • Loftus and Palmer conducted another experiment and found that those who heard smashed reported broken glass when there wasn't any
• post-event discussion: may discuss experiences and memories with eachother

  • Gabbert (2003) studied participants in pairs, made them watch a video on the same crime but filmed from different points of view - then discussed and did a test

  findings: 71% mistakenly recalled events that they did not see but had picked up during discussions
• misleading information evaluation;

  strength:

  • important practical use in the criminal justice system - by not using misleading wording, it protects innocent people from faulty convictions

  Weakness:

  • lab study - usually want to be helpful when answering questions and therefore guess what they should be saying - lead to invalid responses that cannot be generalised
  • Loftus and Palmer experiment took place in a lab, less stressful environment than witnessing a real life event
• anxiety: negative effect on recall

  • creates physiological arousal that prevents us from paying attention to important cues

  Johnson and Scott (1976) - seated waiting room, one group hearing a casual conversation and then a man with a pen in his hand. the other group heard a heated conversation and then a man with a knife in his hand

  • findings: seen man carrying pen 50% could identify him, lower for man holding knife at 33%
• anxiety: positive effect on recall

  fight or flight response: increasing alertness, improving memory as more aware of the cues

  • Yuille and Cutshall (1986) conducted a study of an actual shooting in a gun shop where the owner shot a thief dead
  • 21 witnesses, 13 took part in the study, then interviewed 4-5 months after and compared responses to the original interview
  • asked to rate how stressed they felt at the time and whether they have had any emotional problems since the event

  findings: those with highest level of stress were more accurate - anxiety doesn't effect EWT
• evaluation of anxiety affecting EWT:

  strength:

  • inverted-U theory: reasonable explanation to link them - higher arousal higher accuracy etc

  weakness:

  • Johnson and Scott may not have tested anxiety, participants may have focused on the weapon because they were surprised - Pickel replicated study with chicken and found that accuracy was poorer in unusual conditions
• cognitive interview evaluation:

  strength:

  • meta-analysis from Kohnken, combined data from 55 studies comparing CI and standard police interviews - CI more accurate

  weakness:

  • time-consuming, takes time to train individuals - not realistic method for police officers to use
  • hard to compare the effectiveness of different approaches in research studies
• EWT: cognitive interview

  • Fisher and Gieselman (1992) argued that EWT could be improved if the police used better interviewing techniques

  1. report everything
  2. reinstate the context - imagine environment
  3. reverse the order of events
  4. change perspective to someone else present