Anxiety

• Yerkes-Dodson law states that moderate anxiety increases the accuracy of EWT whereas very high or low levels of anxiety decrease the accuracy of EWT.
• Contradicting evidence about the effects of anxiety on the accuracy of EWT:

  • Negative effect on recall as it creates arousal in the body which prevents us from paying attention to important cues so recall is worse
  • Positive effect on recall as the fight or flight response increases our alertness and improves our memory as we become more aware of cues in the environment
• the 'weapon focus effect' suggests that in violent crimes where a weapon is involved, anxiety may focus the witness on the weapon rather than the other details of the event.
• Research to support the view that anxiety has a negative effect on recall: Johnson and Scott told ppts they were involved in an experiment about memory. Condition 1 had a man emerge from a room with a pen and grease on his hands. 2 had a man emerge holding a letter opener covered in blood. Almost 50% in 1 correctly identified the man from 50 photos whereas around 30% could in 2. This suggests the weapon became a distraction, therefore high levels of anxiety can reduce the accuracy of EWT.
• Research to support the view that anxiety has a positive effect on recall from Christianson and Hubinette. They carried out a survey of 110 people who had witnessed 1 of 22 genuine bank robberies. Some had been bystanders, some had been directly threatened. The people who had been subject to the most anxiety showed more accurate recall, the recall remained after 15 months. This suggests that high levels of anxiety can increase accuracy of EWT.
• EWT research into anxiety: limitation: methodological issues in Christianson's and Hubinette's study. There was a lack of control over extraneous variables as those who experienced the highest levels of anxiety were closer to the event. Being able to see more clearly what happened might have led to a greater EWT accuracy. This means it is not possible to determine whether anxiety levels alone are responsible for the accuracy of EWT.
• Limitation of EWT research into anxiety: ethical issue: psychological harm may be caused by asking people who have been involved in real-life violent incidents to recall their experiences. Ppts can also not give fully informed consent as they cannot be told the true aims of the study. Researchers need to ensure participants are debriefed afterwards and given a chance to assess potential harm.