Factors affecting EWT: anxiety

• Anxiety

  Negative effect on accuracy of eyewitness testimony
• Weapon-focus effect


  Decreased ability to give an accurate description for one perpetrator of a crime by an eyewitness because of attention to a weapon present during that crime
• Weapon-focus study (Johnson and Scot)

  1. Group 1: Low anxiety condition - participants sat in a waiting room, overheard a casual conversation, then saw a man walk past

  2. Group 2: High anxiety condition - participants sat in a waiting room, overheard an argument followed by the sound of breaking glass, then saw a man holding a knife covered in blood
• 49% of group 1 accurately identified the man, compared to 23% of group 2
• Tunnel theory of memory

  People have enhanced memories of central details (e.g. weapon) but can't remember peripheral details (e.g. the man's face)
• The weapon-focus effect decreases the accuracy of eyewitness memory
• Experimental method

  • High internal validity
  • Controlled independent variables
  • Establish cause and effect
  • Standardised procedure
  • Replicated
• Experimental design

  • Independent groups
  • Controls for individual differences
  • No order effects
• Quantitative data has limitations in explaining human behaviour in depth
• Real world applications: Court cases need to consider how anxiety negatively impacts the accuracy of memory and can lead to false identifications/interactions
• Increased anxiety

  Improved memory accuracy in real-world situations
• Yuille & Cutshall (1986) study

  1. Interviewed 21 witnesses 4-5 months after an actual shooting incident

  2. Compared accuracy of details between initial police interviews and later interviews

  3. The more stressed witnesses were, the more accurate their accounts (88% accuracy for most stressed vs 75% for least stressed)
• Anxiety does not have a detrimental effect on memory in real world situations, it may even enhance it
• Support for negative effects

  Valentine + Mesout found that anxiety can affect eyewitness testimony, measured by heart rate, in a London Dungeon study. This shows heightened anxiety can harm recall of details about the actor.
• Unusualness not anxiety

  Elizabeth Pickel's study shows the weapon focus effect is due to unusualness, not anxiety. Unusual items like a handgun or raw chicken impair memory.
• Support for positive effects

  Anxiety can enhance recall. Christianson and Hubinette found 75% accuracy in bank robbery witnesses, higher among those directly involved.
• Counterpoint

  Christianson and Hubinette's delayed interviews may have overwhelmed anxiety effects, decreasing eyewitness testimony accuracy and invalidating the findings.