EWT and anxiety

• Johnson and Scott (1976) - Weapon Focus

  • Px believed they were taking part in a lab study
• Johnson and Scott (1976) - Weapon Focus, low-anxiety condition

  • Px in a waiting room
  • Casual conversation in the next room
  • See a man walk past them carrying a pen and with grease on his hands
• Weapon Focus: high-anxiety condition

  • overheard a heated argument, accompanied by the sound of breaking glass
  • man walked out of the room, holding a knife covered in blood
• Anxiety creates physiological arousal in the body which prevents us paying attention to important cues, so recall is worse.
• One approach to studying anxiety and EWT is to look at the effect of the presence of a weapon which creates anxiety. This leads to a focus on the weapon, reducing a witness's recall for other details.
• Effects of anxiety

  • negative effect: weapon focus
  • positive effect: fight or flight, alertness
  • contradictory findings, optimal anxiety/Yerkes-Dodson Law
• Positive effect of anxiety on recall

  • Witnessing a stressful event creates anxiety through physiological arousal within the body
  • The fight or flight response is triggered, increasing alertness
  • This may improve memory for the event as we become more aware of cues in the situation
• Positive effect on anxiety - study by Yuille and Cutshall (1986)

  • 13 witnesses to a real-life shooting were interviewed for 4 months after the event
  • These interviews were compared with the original police interviews at the time of the shooting
  • Accuracy was determined by the number of details reported in each account
  • Witnesses were also asked to rate how stressed they had felt at the time of the incident (on a 7-point scale) and whether they had any emotional problems since the event (e.g. sleeplessness)
• Positive effect on anxiety - Yuille and Cutshall (1986) findings

  • Witnesses were very accurate in their accounts and there was little change in the amount recalled or accuracy after 5 months
  • Some details were less accurate, such as recollection of the colour of items and age/height/weight estimates
  • Px who reported the highest levels of stress were most accurate (about 88% compared to 75% for the less-stressed group)
  • Suggests that anxiety does not have a detrimental effect on the accuracy of eyewitness memory in a real-world context and may even enhance it
• Who conducted the study on the relationship between emotional arousal and performance in 1908?

  Yerkes and Dodson
• What shape does the relationship between emotional arousal and performance resemble according to Yerkes and Dodson?

  An 'inverted U'
• How many studies did Deffenbacher review regarding EWT in 1983?

  21 studies
• What did Deffenbacher note about the findings on the effects of anxiety?

  There were contradictory findings
• How does the Yerkes-Dodson Law explain the relationship between anxiety and recall accuracy?

  It suggests that lower levels of anxiety produce lower recall accuracy
• What happens to our emotional and physiological state when we witness a crime or accident?

  We become emotionally and physiologically aroused
• What physiological response do we experience as a result of anxiety?


  The fight or flight response
• How does recall accuracy change with increasing levels of anxiety/arousal?

  Memory becomes more accurate as anxiety/arousal increases
• What is the optimal level of anxiety according to the Yerkes-Dodson Law?


  The point of maximum accuracy
• What happens to recall accuracy if an eyewitness experiences too much arousal?

  Recall suffers a drastic decline
• Yerkes-Dodson Law

  The inverted-U theory states that performance will increase with

  stress, but only to a certain point, where it decreases drastically.