Eyewitness Testimony & Anxiety of the Witness

• What is anxiety defined as?

  A state of emotional and physical arousal
• How does anxiety affect eyewitness recall?

  It may make recall better or worse
• What physiological effect does anxiety have on attention?

  It prevents attention to important cues
• What was the aim of Johnson & Scott's (1976) study?

  To investigate anxiety's effect on eyewitness testimony
• What did participants in the low-anxiety condition see?

  A man carrying a pen
• What did participants in the high-anxiety condition see?

  A man carrying a knife covered in blood
• What percentage of participants in the low-anxiety condition identified the man?

  49%
• What percentage of participants in the high-anxiety condition identified the man?

  33%
• What does the tunnel theory of memory suggest?

  Enhanced memory for central events
• What physiological response does anxiety trigger?

  Fight or flight response
• What was the aim of Yuille & Cutshall's (1986) study?

  To record and evaluate witness accounts
• How many witnesses were interviewed in Yuille & Cutshall's study?

  21 witnesses
• What scale did witnesses use to rate their stress?

  A 7-point scale
• What percentage of participants with the highest stress level were accurate?

  88%
• What percentage of less-stressed participants were accurate?

  75%
• What does Deffenbacher (1983) note about anxiety's effects?

  Contradictory findings on recall accuracy
• What does the Yerkes-Dodson Law explain?

  Optimal anxiety level for maximum recall accuracy
• What happens if anxiety exceeds the optimal level?

  Recall suffers a decline
• What are the support findings for negative effects of anxiety on recall?

  • Valentine & Mesout (2009) study
  • High-anxiety disrupted recall of details
  • Weapon focus negatively affected eyewitness accuracy
• What are the support findings for positive effects of anxiety on recall?

  • Christianson & Hubinette (1993) study
  • 75% accuracy across all witnesses
  • Direct victims had even higher accuracy
• What does Pickel (1998) suggest about weapon focus?

  It may be due to unusualness, not anxiety
• What confounding variable is mentioned in Christianson & Hubinette's study?

  Lack of control over participants' experiences
• Why might the findings of Christianson & Hubinette be invalid?

  Confounding variables may affect results
• What is a strength for Anxiety affecting Eyewitness Testimony?

  Support for Negative Effects

  • Valentine & Mesout (2009) supports the research on weapon focus, finding negative effects on recall
  • The researchers used heart rate to divide participants into high-anxiety and low-anxiety groups and in this study, anxiety disrupted the participants’ ability to recall details about the actor in the London Dungeon’s Labyrinth
  • This suggests that a high level of anxiety does have a negative effect on the immediate eyewitness recall of a stressful event
• What is a strength for Anxiety affecting Eyewitness Testimony?

  Support for Positive Effects

  • Christianson & Hubinette (1993) interviewed 58 witnesses to actual bank robberies in Sweden in which some of the witnesses were directly involved and some were indirectly involved
  • Recall was more than 75% accurate across all witnesses and the direct victims, who were the most anxious, were even more accurate
  • These findings from actual crimes confirm that anxiety does not reduce the accuracy of recall for eyewitnesses and may even enhance it
• What is a limitation for Anxiety affecting Eyewitness Testimony?

  Unusualness not Anxiety

  • The reason participants focused on the weapon may be because they were surprised at what they saw rather than being scared
  • Pickel (1998) conducted an experiment using scissors, a handgun, a wallet or a raw chicken as items in a hairdressing salon in which eyewitness accuracy was poorer in the high unusualness conditions
  • This suggests that the weapon focus effect is due to unusualness rather than anxiety and therefore tells us nothing specifically about the effects of anxiety on eyewitness testimony
• What is a limitation for Anxiety affecting Eyewitness Testimony?

  Confounding Variables

  • Christianson & Hubinette (1993) interviewed participants several months after the event and so the researchers therefore had no control over what happened to the participants during the intervening time
  • The effects of anxiety may have been overwhelmed by these other factors and impossible to assess by the time the participants were interviewed
  • Therefore it is possible that a lack of control over confounding variables may be responsible for these findings, invalidating their support