EWT: anxiety

• Anxiety - a state of emotional and physical arousal
• Weapon focus effect - during violent crimes where a weapon is present, more attention is paid by the witness to the weapon. 
• When a witness is anxious about a weapon, their recall for other details decreases because they are paying more attention to the weapon.
• Johnson and Scott led pps to believe they were going to take part in a lab study. Pps sat in a waiting room. There were 2 conditions

  • Low anxiety condition: while seated in a waiting room pps heard an argument in the next room and a man walked through the waiting area carrying a pen with grease on his hands.
  • High anxiety condition: same argument accompanied by sound of broken glass, man walked out of the room carrying a knife covered in blood. 
  • Pps later picked out the man from a set of 50 photos
• Johnson and Scott's findings:

  Knife condition: 33% pps could identify him

  Pen condition: 49% of pps could identify him

  Conclusion - anxiety has a negative effect on recall
• The tunnel theory of memory argues that a witness’ attention narrows to focus on a weapon because it is a source of anxiety
• A stressful event raises physiological arousal, thereby preparing the body for fight or flight. Physiological arousal increases alertness, which improves memory for an event because we become more aware of cues in the situation
• Yuille and Cutshall conducted a study on a real life shooting in a shop in vancouver. Shop owner shot a thief dead. There were 21 witnesses and 13 agreed to be part of the study. Interviews were carried out 4-5 months after compared to real interviews taken at the time of the shooting. 

  Accuracy was determined by the number of details reported in each report. Witnesses also asked to rate how stressed they had felt at the time of the incident using a 7 point scale
• Yuille and Cutshall's findings: witnesses were very accurate in their accounts and there was little change in amount of accuracy. Participants who reported higher anxiety levels of stress were most accurate. 

  Conclusion- anxiety had a positive effect on eyewitness testimony
• Yerkes-Dodson Law: Lower levels of anxiety produce lower levels of recall accuracy. Memory becomes more accurate as the level of anxiety experienced increases. However there comes a point where the optimal level of anxiety is reached. Higher anxiety than this decreases recall.
• the Yerkes-Dodson Law explains why some research shows a negative relationship between anxiety and EWT whilst others show a positive relationship
• Johnson and Scott’s research may test surprise rather than anxiety
• Pickel conducted an experiment in which he tested eyewitness accuracy in a hairdressers, he used scissors, a hand gun and a chicken. He found eyewitness’ accuracy was significantly poorer in the chicken condition
• Yuille and Cutshall’s research use of a field study may lead to lack of control. All sorts of things may have happened in the meantime that could alter an eyewitness testimony (confounding variables)
• Johnson and Scotts’ research could be criticised for having unethical aspects. Creating high anxiety in pps can be seen as very risky because it may subject participants to psychological harm only for research purposes