Accuracy of EWT: Anxiety

Question 1

Give research supporting that anxiety has a negative effect on accuracy

Answer 1

• Johnson and Scott (1976) investigated weapon focus effect, a weapon in a criminal’s hand distracts attention and reduces accuracy of identification
• Procedure: Participants were asked to sit in a waiting room where they heard an argument. A man ran through the room with either a pen covered in grease (low anxiety condition) or a bloody knife (high anxiety condition). Participants then had to identify the man from photos.
• Findings: Mean accuracy was 49% in identifying the man in the pen condition, compared to 33% in the knife condition.
• Loftus et al (1987) showed anxiety does focus attention on central features of a crime (weapon) They monitored eyewitness’ eye movements and found a weapon cause attention to be physically drawn to it

Question 2

Give research that supports that anxiety has a positive effect on accuracy

Answer 2

• High anxiety creates enduring and accurate memories. An evolutionary argument is it would be adaptive to remember events that are emotionally important so you could identify similar situation and recall how to respond.
• Procedure: Christianson and Hubinette (1993) questioned 58 witnesses to bank robberies in Sweden. Witnesses were either victims (bank tellers and high anxiety) or bystanders (customers and low anxiety). Interviews happened 4-15 months after the event
• Findings: All witnesses were better than 75% accurate in recall. Those who were most anxious had the best recall. Study shows anxiety doesn’t reduce accuracy of recall
• Christianson (1992) concluded that memory for negative emotions events is better than for neutral events, at least for the central details.

Question 3

Describe Deffenbacher’s research

Answer 3

• He reviewed 21 studies of the effects of anxiety on eyewitness memory, He found that 10 of these linked higher arousal levels to increased eyewitness accuracy while 11 showed the opposite
• He suggested the Yerkes-Dodson effect, when arousal is only moderate then eyewitness accuracy (performance) would be enhanced. When arousal is too extreme then accuracy will be reduced (U-shaped curve)

Question 4

Give a strength for effects of anxiety on accuracy

Answer 4

Christianson and Hubinette’s research has good external validity. A methodological with studies into EWT is they rely on artificial crimes where participants have little consequences and so motivation in their testimony. However, their research was conducted on a real-life event where anxiety was genuine and their testimonies had consequences. Suggests it provides a useful and valid depiction of the role of anxiety. However there are issues with a lack of control over extraneous variables, e.g. post-event discussion may have occurred in between the time they were interviewed and the crime and researchers have no control over this.

Question 5

Give limitations for the effects of anxiety on accuracy

Answer 5

• The weapon focus effect may be due to surprise rather than anxiety. Pickel (1998) arranged for participants to watch a thief enter a salon with scissors (high threat, low surprise), handgun (high threat, high surprise), wallet (low threat, low surprise) or a raw chicken (low threat, low surprise). Identification was least accurate in the high surprise rather than high threat. Supports weapon focus effect is related to surprise.
• Contradictory findings means that it’s difficult to establish the effect of anxiety. Many studies of anxiety didn’t involve violence. Similar to Christianson and Hubinette, Halford and Milne (2005) found victims of violent crimes were accurate in their recall of crime scene info than victims of non-violent crimes. Shows there is no simple rule about the effect of anxiety on accuracy of eyewitness testimony
• The relationship between anxiety and performance may be more complex than the Yerkes-Dodson model predicts. The model only accounts for physiological arousal. The catastrophe theory accounts for physiological and cognitive anxiety (worry). As physiological arousal and cognitive anxiety, there’s a sharp decrease in performance. Suggests an alternative model fits better with research findings.