Factors affecting the accuracy of EWT: anxiety

• Anxiety is a state of emotional and physical arousal. It involves physiological responses (like increased heart rate) and psychological effects (such as fear or tension).
• The Yerkes-Dodson law states that performance is best when there's moderate levels of arousal, but too little or too much will lead to poorer performance
• The weapon focus effect is when the anxiety of seeing a weapon focuses all your attention on the weapon and this means that you won't be able to recall much else.
• Anxiety can have a negative effect on recall as it causes psychological arousal which prevents us paying attention to important cues, so recall is worse. 
• Johnson and Scott studied how anxiety can have a negative effect:

  • Method: 2 conditions a 'low anxiety' and a 'high anxiety’. In the 1st condition, the ppts heard an argument while seated in the waiting room and saw a man walk past carrying a pen with grease on his hands. In 2nd condition, ppts overheard an argument also, but heard the sound of glass breaking which was followed by a man walking past with a paper knife covered in blood.
  • Results: From a set of 50 photos, 49% of ppts in the 'low anxiety' condition picked the correct man, compared to 33% in 'high anxiety' condition.
  • Conclusion: tunnel theory of memory
• The tunnel theory of memory argues that witness’ attention narrows to focus on a weapon, because it is the source of anxiety, while ignoring peripheral details. As a result, they are less likely to encode or recall other important details.
• Anxiety can have a positive effect on recall. This is because the stress of witnessing a crime or accident triggers one’s fight-or-flight response which increases our alertness and improve our memory for the event as we become more hyperaware of cues in the situation. 
• Yuille and Cutshall investigated how anxiety can have a positive effect on recall:

  • Method: They conducted a study of a real-life shooting in a gunshop in Vancouver, Canada. They interview 13 participants who had been witnesses of the crime that occurred around 4-5 months ago and compared the accuracy of their recall of the details of the crime to the original police interviews. Witnesses were also asked to indicate on a 7-point scale how stressed they were at the time of the crime and were asked if they had suffered from any emotional problems due to the event.
• Yuille and Cutshall investigated how anxiety can have a positive effect on recall:

  • Results: found that were little change in the accuracy of their accounts but only less accurate in some details such as recall of colour of items, age, weight or height estimates. They also found that participants who reported the highest levels of stress were more accurate in their recall of the event (88% compared to 75% for less stressed groups). 
• A weakness of research into the effect on anxiety on EWT is that the weapon focus effect might not be relevant. This is because Pickel (1998) criticised the weapon effect as he believed that it was the unusualness/surprise of the weapon rather than the threat that causes low accuracy when recalling the details of a crime. He conducted an experiment in the hairdressers where he found that eyewitness accuracy was significantly lower in high unusualness conditions (handgun and chicken). This then means that weapon focus effect tells us nothing about the effects of anxiety on EWT.
• A weakness of a field study like Yuille and Cutshall’s is its lack of control of extraneous variables. This is because before the study, participants’ recall of the event could have been affected by post-event discussions, the media or other things that the researchers have no control over. This therefore limits the study as these variables may have affected recall also, making it hard for the researchers to assess the effect of just anxiety on eye-witness recall. 
• A strength of Yuille and Cutshall’s investigation is its high ecological validity. The use of a real-life event increases the validity of the findings of the study because the stimuli has meaning to the participants, so they are likely to preform better. This means that the findings can be generalised more easily to real-life eye-witness testimonies and help us understand how anxiety can positively affect recall.