anxiety (eyewitness testimony)

• Johnson and Scott, anxiety has a negative effect (procedure)

  • Participants sat in a waiting room believing they were going to take part in a lab study
  • Low-anxiety condition = participants heard a casual conversation, then saw a man walk through the waiting room carrying a pen with grease on his hands
  • High-anxiety condition = a heated argument was accompanied by the sound of breaking glass. A man then walked through the room holding a knife covered in blood (creates anxiety and ‘weapon focus’)
  • Participants were later asked to pick the man from a set of 50 photographs
• Johnson and Scott, anxiety has a negative effect (findings/conclusions)

  • 49% of participants in the low-anxiety condition and 33% of high-anxiety participants were able to identify the man
  • Tunnel theory of memory = argues that people have enhanced memory for central events
  • Weapon focus as a result of anxiety can have this effect
  • Weapon focus = witness’s attention focused on weapon leading to less attention on other details of the event
• Yuille and Cutshall, anxiety has a positive effect (procedure)

  • In an actual crime, a gun-shop owner shot a thief dead
  • 13 out of the 22 witnesses agreed to participate in the study
  • participants were interviewed 4-5 months after the incident
  • The information recalled was compared to the police interviews at the time of the shooting
  • Witnesses also rated how stressed they felt at the time of the incident
• Yuille and Cutshall, anxiety has a positive effect (findings/conclusions)

  • Witnesses were very accurate in what they recalled and there was little change after 5 months
  • Some details were less accurate = eg age, weight, height
  • Participants who reported the highest levels of stress were most accurate
  • About 88% compared to 75% for the less stressed group
  • Anxiety does not appear to reduce the accuracy of EWT for a real-world event and may even enhance it
• Explaining the contradictory findings of anxiety

  • Inverted-U theory
  • Yerkes and Dodson = argues that the relationship between performance and arousal/stress is an inverted U
  • Performance will increase with stress but only to a certain optimum point, and then performance will decrease
  • Deffenbacher = revised 21 studies of EWT with contradictory findings on the effects of anxiety on recall
  • He suggested the Yerkes-Dodson effect could explain this = both low and high levels of anxiety produce poor recall whereas optimum levels can lead to very good recall
• limitation = anxiety may not be relevant to weapon focus

  • Johnson and Scott’s participants may have focused on the weapon not because they were anxious but because they were surprised
  • Pickel = found accuracy in identifying the ‘criminal’ was poorest when the object in their hand was unexpected
  • Eg = raw chicken and a gun in a hairdressers (both unusual)
  • This suggests the weapons effect is due to unusualness rather than anxiety/threat and so tells us nothing about the specific effects of anxiety on recall
• strength = supporting evidence for negative effects

  • Valentine and Mesout = used heart rate (objective measure) to divide visitors to the London Dungeon’s Labyrinth into low- and high-anxiety groups
  • High-anxiety participants were less accurate than low-anxiety in describing and identifying a target person
  • This supports the claim that anxiety has a negative effect on immediate eyewitness recall of a stressful event
• Strength = supporting evidence for positive effects

  • Christianson and Hubinette = interviewed actual witnesses to bank robberies
  • Some were direct victims (high anxiety) and others were bystanders (less anxiety)
  • They found more than 75% accurate recall across all witnesses
  • Direct victims (most anxious) were even more accurate
  • Suggests that anxiety does not affect the accuracy of eyewitness recall and may even enhance it
• counterpoint to supporting evidence for positive effects

  • Christianson and Hubinette = interviewed witnesses long after the event
  • Many things happened that the researchers could not control (eg post-event discussions)
  • => lack of control over confounding variables may be responsible for the (in)accuracy of recall, not anxiety
• extra evaluation = problems with the inverted-U theory

  • The inverted-U theory appears to be a reasonable explanation of the contradictory findings linking anxiety with both increased and decreased eyewitness recall
  • BUT = it only focuses on physical anxiety and ignores other elements, including cognitive (how we think about a stressful event affects what we recall)
  • => the invert-U explanation is probably too simplistic to be useful (eg anxious thoughts may not always lead to symptoms of anxiety but may block memory)