Factors affecting accuracy of ewt- anxiety

• anxiety has strong emotional and physical affects however its not clear if these effects make recall better of worse. There is research support for both
• Anxiety has a negative effect on recall ( weapon focus)

  • anxiety creates a physiological arousal in the body preventing us from paying attention to important cues, so recall is worse. One way to look at anxiety and ewt is to look at the effects of the presence of a weapon which creates anxiety. This leads to a focus on the weapon, reducing recall for other details of the event.
• Anxiety as a negative effect procedure

  • Johnson and Scott got participants to believe they were taking part in a lab study. While in the waiting room participants in the low anxiety condition heard a casual conversation in the next room and saw a man walk past carrying a pen with grease on his hand. In the high anxiety condition participants heard a heated argument, broken glass and a man walked out of the room holding a knife covered in blood.
• Findings to anxiety as a negative effect

  • participants later picked out the man from a set of 50 photos ,49% who saw the man carrying the pen were able to identify him compared to 33% for the high anxiety condition.
  • Tunnel theory of memory suggests people have an enhanced memory for central events. Weapon focus as a result of anxiety has this effect.
• anxiety as a positive effect

  witnessing a stressful event creates anxiety through physiological arousal . This triggers the flight or fight response which increases alertness. This may improve memory an we become more aware of cues in the situation.
• Anxiety as a positive effect on recall

  • Yuille and Cutshaw studied an actual shooting in a gun shop Vancouver, Canada. The shop owner shot a thief dead and there were 21 witnesses - 13 took part in the study. They were interviewed 4-5 months after the incident and these interviews were compared to the original police interviews at the time. Accuracy was determined by the details reported in each account and the witnesses were asked how stressed they had felt as the time of the incident ( on a 7 point scale). They were also asked if they has emotional problems since the event.
• Findings of anxiety as a positive effect on recall

  • witnessed were very accurate in their accounts and there was little change in the amount of recall after 4-5 months. Some detailed were less accurate but these were minor e.g recollection of the colour of an item. Those who reported the most stress were the most accurate ( about 88% compared to 75% for the less stressed group) . This suggests anxiety does not have serious effects on accuracy of ew memory and may actually enhance it.
• Explaining these different findings

  Yerks and Dodson believe the relationship between emotional arousal and performance looks like an inverted u. The inverted U theory states that performance will increase with stress but only up to a certain point where it will then decrease. Deffenbacher reviewed 21 studies of EWT and noted the contradictory findings on the effects of anxiety. He used the Yerks Dodson law to explain these and found when we witness a accident we become emotionally and physiologically aroused (the fight or flight response). Lower levels of anxiety produce lower levels of recall accuracy and memory becomes more accurate as anxiety increases. However there's an optimal level of anxiety which is the maximum accuracy if a person experiences any more arousal beyond maximum accuracy their recall will suffer a decline
• Eval 1 - unusualness nor anxiety

  • limit is that the study by Johnson and Scott might not have tested anxiety. The reason participants focused on the weapon may be because they were surprised at what they saw. Pickel conducted an experiment using scissors, handgun, wallet or raw chicken as hand held items in a hairdressing video ( where scissors would be high anxiety , low unusualness). Eyewitness accuracy was poorer in high unusualness conditions ( chicken and handgun).
  • This suggests weapon focus effects could be due to unusualness rather than anxiety .
• Eval 2- support for negative effects

  strength is evidence supporting the view that anxiety has a negative effect on accuracy of recall. Valentine and Mesout found anxiety had a negative effect recall. The researcher used a heart rate to decide participants into high or how anxiety groups. In the study anxiety disrupted the participants ability to recall details about the actor in London dungeons labyrinth. This suggests high levels of anxiety has a negative effect on eyewitness recall.
• Eval 3- support for the positive effects

  a strength is the evidence showing anxiety can have positive effects on the accuracy of recall. Christianson and Hübinette interviewed 58 witnesses to a bank robbery in Sweden. Some witnesses were directly involved ( bank workers )and some were indirectly involved ( bystanders). Researchers assumed those directly involved would experience the most anxiety .It was found recall was more than 75% accurate across all witnesses. The direct victims ( most anxious) were even more accurate.

  These findings confirm anxiety does not reduce accuracy of recall for ew but actually enhance it.
• Eval 4- cp to Eval 3

  Christianson and hübinette interviewed their participants several months after the event ( 4-15). The researchers therefor had no control over what happened to their participants in the intervening time (post event discussion). The effects of anxiety may have been overwhelmed by these other factors and there could also be a lack of control over confounding variables which could be responsible for there findings.
• Eval 5- problems with the inverted u theory

  • the inverted U theory appears to be a reasonable exp of the contradictory findings linking anxiety to increased and decreased eyewitness recall.
  • On the other hand, it ignores that anxiety has many other elements - cognitive, behavioural, emotional and physical. It focuses on just the last two and assumes this is the only aspect linked to ewt. But the way we think about the stressful situation may also be important ( Cognitive).