Effect of anxiety on EWT

Anxiety or stress is almost always associated with real life crimes of violence.  Deffenbacher (1983) reviewed 21 studies and found that the stress-performance relationship followed an inverted-U function proposed by the Yerkes Dodson Curve (1908).  This means that for tasks of moderate complexity (such as EWT), performances increases with stress up to an optimal point where it starts to decline.

Clifford and Scott (1978) found that people who saw a film of a violent attack remembered fewer of the 40 items of information about the event than a control group who saw a less stressful version.  As witnessing a real crime is probably more stressful than taking part in an experiment, memory accuracy may well be even more affected in real life. However, a study by Yuille and Cutshall (1986) contradicts the importance of stress in influencing eyewitness memory. They showed that witnesses of a real life incident (a gun shooting outside a gun shop in Canada) had remarkable accurate memories of a stressful event involving weapons. A thief stole guns and money, but was shot six times…