EWT

What is anxiety?

• A state of emotional arousal where there is a feeling of apprehension and uncertainty.
• Anxiety may affect the accuracy of eyewitness testimony.

Research: Anxiety has a negative effect

• Loftus (1979) conducted an experiment to see if anxiety affects the accuracy of EWT and facial recognition.
• Participants sat in a waiting room believing they were going to take part in a lab study.
• Each participant heard an argument in the next room.
• The experiment used an independent groups design: in the low anxiety condition a man then walked through the waiting room carrying a pen with grease on his hands. In the high anxiety condition the heated argument was accompanied by the sound of breaking glass.A man then walked through the room holding a paper knife covered in blood.
• 5. Both groups were asked to identify the man from a set of 50 photographs.
• Findings:
• 6. 49% of participants in the low-anxiety condition were able to identify him compared to 33% of high anxiety participants.

Conclusion:

• Loftus claimed that the participants who were exposed to the knife had higher levels of anxiety and were more likely to focus their attention on the weapon and not the face of the target.
• This is the weapon focus effect.
• Therefore, the anxiety associated with seeing the knife reduces the accuracy of eyewitness testimony.

Evaluation: Loftus (1979)

• 1. A limitation of Loftus's study is that it may test surprise, not anxiety.
• Participants may focus on a weapon because they are surprised at what they see, not scared.
• Picker (1998) used scissors, a handgun, a wallet and raw chicken as hand held items in a hairdressing salon. EWT accuracy was poorer for high unusualness (chicken and handgun).
• So, the weapon focus effect may be due to unusualness rather than anxiety and so the study lacks internal validity as it does not actually measure the effect of anxiety on eyewitness testimony.
• 2. A further limitation is that numerous ethical guidelines were broken.
• The participants were deceived about the nature of the experiment and were not protected from harm. Loftus exposed some participants to a man holding a bloodied knife which could have been an issue as participants may have left the experiment feeling exceptionally stressed and anxious, especially if they have been involved in a knife crime in the past.

Slide 5

• 3. There is supporting evidence for anxiety having a negative effect on accuracy of EWT testimony by Loftus and Burns (1982).
• In this study, participants were less accurate in recall when they watched a violent short film where a boy was shot in the head than those who watched a non-violent short film of a crime.
• This demonstrates support for Loftus (1979) as it shows that when people witness anxiety provoking situations, they are less likely to accurately recall the event.
• 4. A real life case study by Yuille and Cutshall (1986) contradicts the results of Loftus (1979) and the weapon focus effect.
• They found that witnesses of a traumatic real life gun crime were very accurate and there was little change to their testimonies five moths after the incident.
• Participants who reported the highest level of stress were the most accurate (88% compared to 75%) showing that in real life situations of extreme anxiety, the accuracy of eyewitness testimony is not affected.
• This reduces the reliability of Loftus's findings as repeated studies have not obtained the same results as his.

Research: Anxiety has a positive effect

• 1. Yuille and Cutshall's real life case study contradicts the results of Loftus (1979) and the weapon focus effect.
• 2. In a real life crime, a gun shop owner shot a thief dead.
• 3. There were 21 witnesses and 13 agreed to participate in the study.
• 4. Participants were interviewed 4-5 months after he incident and accounts were compared to police interviews at the time of the shooting.
• 5. Witnesses rated how stressed they felt at the time of the incident.
• Findings:
• 6. Witnesses were very accurate and there was little change in their testimonies after 5 months.
• Participants who reported the highest level of stress were the most accurate (88% to 75%) showing that in real life situations of extreme anxiety, the accuracy of eyewitness testimony is not affected.

Evaluation:

• 1. A limitation is that this was a field study and therefore lacked control of extraneous variables which may be responsible for the accuracy of recall, not anxiety.
• Real life witnesses are interviewed sometime after the event.
• Many things happen to them in the meantime such as post-event discussions or reading accounts in the media which cannot be controlled by researchers and may influence their memory. This reduces the validity of the findings.

Yerkes-Dodson Curve (1908)

• The inverted U theory states that performance will increase with stress but only to a certain point, after which it decreases dramatically.
• Yerkes and Dodson argue that the relationship between performance and stress is curvilinear rather than linear.
• Deffenbacher (1983) found that lower levels of anxiety did produce lower levels of recall accuracy.
• Recall accuracy increases with anxiety up to an optimal point.
• A drastic decline in accuracy is seen when an eyewitness experiences more anxiety than the optimal point.

Evaluation of inverted U theory

• A limitation is that the inverted-U explanation is too simplistic.
• It only looks at how physiological arousal affects anxiety and fails to account for other factors including the emotional experience of witnessing a crime (e.g. fear) on the accuracy of memory, therefore the explanation may be seen as reductionist.
• Fazey and Hardy (1988) proposed the catastrophe theory which may explain anxiety effects on eyewitness testimony better as it includes performance, physiological arousal and cognitive anxiety as well.
• This may be a more holistic explanation for anxiety effects on the accuracy of memory than the inverted U theory,