Eyewitness testimony: anxiety

• What are the two theories of how anxiety affects recall?

  1. positively
  2. negatively
• What did Johnson and Scott (1976) believe?

  They believed that anxiety has a negative affect on recall.
• What was Johnson and Scott's procedure?

  • Participants believed they were taking part in a lab study and are sitting in a waiting room
  • Two conditions:

  1. low anxiety: overheard a casual conversation in the next room and then saw a man walk past them carrying a pen with grease on his hands
  2. high anxiety: overheard a heated argument, accompanied by the sound of breaking glass. A man walked out of the room, holding a knife covered in blood.

  • The participants later picked out the man from a set of 50 photos
• What were Johnson and Scott's findings and conclusions?

  • 49% who had seen the man carrying the pen were able to identify him
  • 33% who had seen the man holding the blood-covered knife were able to identify him
  • Anxiety creates physiological arousal in the body which prevents us paying attention to important cues, so recall is worse
  • The tunnel theory of memory argues that people have enhanced memory for central events
  • Weapon focus because of anxiety can have this effect
• What did Yuille and Cutshall (1986) believe?

  They believed that anxiety has a positive effect on recall.
• What was Yuille and Cutshall's procedure?

  • Conducted a study of an actual shooting in a gun shop in Vancouver, Canada
  • The shop owner shoots a thief who is killed by the shot. There were 21 witnesses- 13 took part in the study
  • They were interviewed four to five months after the incident and 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
  • The 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.
• What were Yuille and Cutshall's findings and conclusions?

  • Witnesses were very accurate, there was little change in accounts
  • Those who reported the highest levels of stress were most accurate
  • 88% accuracy in anxious compared to 75% for the less-stressed
  • This suggests that anxiety does not have a detrimental effect on the accuracy of eyewitness memory in real-world context and may even enhance it.
  • Witnessing a stressful event creates anxiety though 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.
• What did Yerkes and Dodson (1906) suggest?

  • They created the inverted-U theory
  • They argued that the relationship between performance and arousal/stress is an inverted U
  • It shows that performance will increase with stress, but only to a certain point
• Limitation: unusualness not anxiety

  P- One limitation of the study by Johnson and Scott is that it may not have tested anxiety

  E- The reason ppts focused on the weapon may be because they were surprised at what they saw rather than scared. Pickel conducted an experiment using scissors, a handgun, a wallet or a raw chicken as the hand-held items in a hairdressing video

  E- Eyewitness accuracy was significantly poorer in the high unusualness conditions

  L- This suggests that the weapon focus effect is due to the unusualness rather than anxiety/threat and therefore tells us nothing specifically about the effects of anxiety on EWT
• Strength: Supports for negative effects

  P- One strength is that there is evidence supporting the view that anxiety has a negative effect on the accuracy of recall

  E- Valentine and Mesout supports the research on weapon focus, finding negative effects on recall. The researchers used an objective measure (heart rate) to divide ppts into high and low anxiety groups

  E- In this study anxiety clearly disrupted the ppts ability to recall details about the actor in the London dungeon's Labyrinth

  L- This suggests that a high level of anxiety does have a negative effect on the immediate eyewitness recall of a stressful event
• Strength: supports for positive effects

  P- Another strength is evidence showing that anxiety can have positive effects on the accuracy of recall.

  E- Christianson and Hubinette interviewed 58 witnesses to actual bank robberies in Sweden. Some of the witnesses were directly involved and some were indirectly involved.

  E- The researchers assumed that those directly involved would experience the most anxiety. It was found that recall was more than 75% accurate across all witnesses.

  L- these findings from actual crimes confirm that anxiety does not reduce the accuracy of recall for eyewitness and may even enhance it.
• Limitation: inverted U theory issues

  P- The inverted U theory appears to be a reasonable explanation of the contradictory findings linking anxiety with both increased and decreased eyewitness recall

  E- On the other hand it ignores the fact that anxiety has many elements cognitive, behavioural, emotional and physical. It focuses on just the last of these and assumes this is the only aspect linked to EWT.

  E- But the way we think about the stressful situation may also be important

  L- Therefore, it could be argued that the inverted- U theory explanation is too simplistic.