Eye-Witness Testimony

• What does Loftus & Palmer‘s (Exp 1) study show about leading questions?

  • PPs were shown videos of car accidents then asked how fast were the cars going
  • In each group a different verb was used for ‘crashed’
  • The more ‘violent’ the verb used, the higher the speed they guessed
• What does Loftus & Palmer’s (Exp 2) show about leading questions?

  • A new set of PPs were asked a follow up question of whether there was any broken glass
  • PPs who thought the car was driving faster in the initial question were more likely to say yes when there wasn’t any glass
• What does Wright’s study show about post-event discussion?

  • Two separate groups of PPs shown images of a woman stealing a man’s wallet (one video she had an accomplice, the other she was on her own)
  • The two groups merged to discuss and then asked whether she had an accomplice
  • The majority of PPs agreed with who they paired with - an example of the conformity effect
• How can repeat interviewing affect EWT?

  Leading questions can become incorporated into the witness’ original memory
• What are strengths and limitations of misleading information (leading questions, post-event discussion)

  • Lab experiments lack ecological validity
  • Real-life application - useful knowing what can affect an eye-witness
• How does Johnson & Scott’s study show anxiety having a negative effect?

  • PPs sat in a fake waiting room and hear an argument from the next room
  • A man (actor) then walks out with either a fake knife with blood on his hands or a pen with grease
  • Recall of the man’s face was better when the man wasn’t holding a potential weapon - supports the ’tunnel theory’
• How does Yuille & Cutshall’s study show anxiety having a positive effect?

  • PPs were real life witnesses of a shooting who were interviewed again 4-5 months after the proper police interview
  • Asked to rate how stressed they were and recall was compared to their first interview
  • PPs were still very accurate - those with higher stress levels had more accurate recall
• How does Yerkes-Dodson inverted U explain contradicting findings about anxiety?

  It suggests that there is an optimum level of anxiety on how far anxiety can improve performance, if it exceeds this level then recall performance will decline
• What are strengths and limitations of effects of anxiety?

  • Yerkes-Dodson explaining contradictory findings is reductionist - anxiety has many elements such as emotional & cognitive aspects
  • Yuille & Cutshall’s study has high ecological validity
  • Pickel’s study argues that tunnel theory isn’t due to anxiety - it is due to surprise
• What are the four key parts of the cognitive interview?

  • Recall everything - to trigger other memories
  • Context reinstatement - for visual cues
  • Reverse order - prevents dishonesty
  • Change perspective - avoids biased expectations
• Who proposed the cognitive interview?

  Fisher and Geiselman
• What does Geiselman’s study show about the cognitive interview?

  • PPs watched a violent crime film and interviewed about it using either standard interview, cognitive or hypnosis
  • Cognitive was the best form of interview with the most accurate recall
• What are strengths and limitations of the cognitive interview?

  • CI is time-consuming
  • Real-life application - provides police with more accurate accounts of crime
  • Supporting evidence