Factors Effecting Eye Witness Testimony

• Who investigated the effects of leading questions on eyewitness testimonies?

  Loftus and Palmer
• What was the aim of Loftus and Palmer's research into leading questions?

  To investigate the effects of leading questions on the accuracy of eyewitness testimony.
• What was the procedure of Loftus and Palmer's research into leading questions?

  A sample of 45 American students, who were divided into five groups of 9.

  An independent measures design was used where participants watched a video of a car crash and were then asked a specific question about the speed of the cars.

  Loftus and Palmer manipulated the verb used in the question, for examples

  "how fast were the cars going when they smashed/collided/bumped/hit each other?"
• What were the findings of Loftus and Palmer's research into leading questions?


  The mean speed estimates (Mph) in:

  • The "smashed" verb condition = 40.5
  • The "contacted" verb condition = 31.8
• Misleading information refers to incorrect information being given to an eyewitness (usually after the event) that can influence the details and accuracy of their recall of the event.
• What are the two examples of misleading information?

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

  A question which, because of the way it is phrased, suggests a certain answer.

  For example; 'was the knife in the accused's left hand?'
• What is post-event discussion?

  This is when the witnesses of the same crime are allowed to discuss the details of their testimonies with each other.
• Who investigated post event discussion?

  Gabbert et al.
• What was the aim of Gabbert et al.'s investigation into post event discussion?

  To investigate the effects of post-event discussion on the accuracy of eyewitness testimony.
• What was the sample in Gabbert et al.'s investigation into post event discussion?


  A sample of 60 students from the University of Aberdeen and 60 other adults.
• Procedure of Gabbert's investigation into post event discussion

  • Participants watched a video of a girl stealing money from a wallet. After watching the video they were either tested individually (control) or in pairs (co-witness group)
  • Participants of the co-witness group were told that they had watched the same video; however, they had in fact seen different perspectives of the same crime, only one had actually witnessed the girl steeling. Participants in this group then discussed the crime together
  • After, all of the participants completed a questionnaire, testing their memory of the event
• What were the findings of Gabbert's investigation into post event discussion?

  • 71% of the witnesses in the co-witness group recalled information they had not actually seen.
  • 60% said that the girl was guilty, despite the fact that they had not seen her commit the crime.
  • 0% of the control group recalled information that they had not actually seen.
• What was the conclusion of Gabbert's investigation into post event discussion?

  The findings highlight the issue of post-event discussion and the powerful effects this can have on the accuracy of eyewitness testimony.
• What is the response bias explanation for misleading information?

  This explanation suggests that the wording of the question has no real effect on the participants memory, but it just influences how they decide to answer. This was shown when the word 'smashed' encouraged a higher speed estimate
• What research can support the response bias explanation for misleading information?

  Loftus and Palmer's leading question study.
• What is the substitution explanation for misleading information?

  This explanation suggests that the wording of a leading question changes the participants memory. This was shown when later on the wording of 'smashed' made the participant more likely to report broken glass.
• What research can support the substitution explanation for misleading information?

  Loftus and Palmer's second experiment.
• What is the memory contamination explanation for misleading information?

  This explanation suggests that when co-witnesses to a crime discuss it with each other, their memory becomes distorted. This is because they combine (mis)information from other witnesses and their own. The actual memory is changed.
• What is the memory conformity explanation for misleading information?

  This explanation suggests that witnesses often go along with each other to gain social approval or because they believe the others to be right. The actual memory is unchanged.
• Who investigated the effects of anxiety on eyewitness testimony and facial recognition?

  Johnson and Scott
• What was the aim of Johnson and Scott's study into anxiety?

  To investigate whether anxiety effects the accuracy of eyewitness testimony and facial recognition.
• What was the procedure of Johnson and Scott's study into anxiety?

  They invited participants into a lab where they were told to wait in the reception area. A receptionist, who was seated nearby excused herself to run an errand, leaving the participant alone. The experiment used an independent groups design, as participants were then exposed to one of two conditions.
• What were the two conditions in Johnson and Scott's study into anxiety?

  • In the ‘non-weapon’ condition, participants overheard a conversation in the lab about equipment failure. Thereafter an individual (the target) left the lab and walked passed the participant holding a pen with his hands covered in grease.
  • In the ‘weapon’ condition, participants overheard a heated exchange and the sound of breaking glass and crashing chairs. This was followed by an individual (the target) running into the reception area holding a bloodied letter opener.
• In Johnson and Scott's study into anxiety what happened after the participants either saw a man walk past or a man running past with a bloodied letter opener?

  Both groups were then shown 50 photographs and asked to identify the person who had left the lab. The participants were informed that the suspect may, or may not be present in the photographs.
• What were the findings of Johnson and Scott's study into anxiety?

  Those who had witnessed the man holding a pen correctly identified the target 49% of the time, compared to those who had witness the man holding a knife, who correctly identified the target 33% of the time.
• What was the conclusion of Johnson and Scott's study into anxiety?

  The findings suggest that anxiety (associated with seeing a knife) does decrease the accuracy of eyewitness testimony and facial recognition. Loftus claimed that the participants who were exposed to the knife had higher levels of anxiety and were more likely to focus their attention on the weapon and not the face of the target, a phenomenon known as the weapon focus effect.
• Who investigated the effects of anxiety in a real life shooting?

  Yuille and Cutshall
• What was the aim of Yuille and Cutshall's investigation into the effects of anxiety?

  To investigate the effects of anxiety in a real life shooting, in which one person was killed and another person seriously wounded.
• What was the procedure of Yuille and Cutshall's investigation into the effects of anxiety?

  13/21 of the original witnesses (aged 15 to 32) were re-interviewed 4-5 months later. Accuracy was measured by the number of details recalled, They were also asked how anxious they felt at the time on a scale of 1-7.
• What were the findings of Yuille and Cutshall's investigation into the effects of anxiety?

  • A participant that reported high anxiety recalled info with 88% accuracy compared to 75% for those with little anxiety.
  • Witnesses who had been most distressed at the time of a shooting gave the most accurate account five months later.
• What was the conclusion of Yuille and Cutshall's investigation into the effects of anxiety?

  In real life cases of extreme anxiety, the accuracy of eyewitness testimony is increased.
• What is Yerkes Dodson Law?

  This is the law that a small increase in anxiety and arousal may increase the accuracy of memory, but high levels have a negative effect on accuracy of memory
• Fill in the blank:

  • Performance and arousal can be substituted for accuracy of memory and level of anxiety.

  A) attention

  B) interest

  C) arousal

  D) performance

  E) performance

  F) strong anxiety