7. Anxiety - Factors affecting the accuracy of EWT

• What is anxiety?

  • State of emotional and physical arousal
  • Emotions include worried thoughts and feelings of tension
  • Physical changes include increased heart rate and sweatiness
  • Can have positive and negative effects on the accuracy of EWT
• What is the weapon focus effect?

  • Proposed by Loftus
  • Anxiety is caused as a result of witnessing a weapon which focuses attention away from potential perpetrators and reduces accuracy of EWT
• Who carried out research into anxiety having a negative impact on the accuracy of EWT?

  Johnson and Scott
• Describe Johnson and Scott's research into the negative impact of anxiety on the accuracy of EWT

  • Participants were told to wait in a reception area
  • Independent groups design: 'no weapon' = participants overheard an argument in the lab and an individual left the lab and walked past holding a pen with hands covered in grease
  • Weapon condition = Heard the sound of breaking glass and individual held a bloodied letter opener
  • 50 photographs - those witnessed a man with a pen identified 49% correctly, letter opener = 39%
  • Anxiety associated with seeing a knife reduces accuracy of EWT
• Who carried out research into anxiety having a positive impact on the accuracy of EWT?

  Yuille and Cutshall
• Describe Yuille and Cutshall's research into the positive impact on the accuracy of EWT

  • Conducted a study on a real life shooting - shop owner shot a thief dead - there were 21 witnesses, 13 took part
  • Interviews occurred 4 months after the incident and were compared to the original EWT
  • Accuracy was determined on the number of details reported
  • Rated stress levels on a 7 point scale
  • Those with the highest stress levels were the most accurate (88% compared to 77%)
• What is the inverted U hypothesis?

  • Suggests the relationship between emotional arousal and performance looks like an inverted U
  • Lower levels of anxiety produced lower recall and memory becomes more accurate as the level of anxiety increases
  • There's a optimal level of anxiety that's reached - if there's more stress than this, recall suffers a drastic decline
• Evaluation of the impact of anxiety on the accuracy of EWT

  • Element of surprise should be considered
  • Ethical issues should be considered - subject to psychological harm - questions the needs for such research
  • Field studies lack control - researchers have no control over discussion with other people about the event e.g. media