Effects of Anxiety

• What is the Weapon Focus Effect?

  Where anxiety causes the witness to focus their attention on the weapon being used in a crime, leads to difficulties in recalling the other details accurately
• How did Johnson and Scott investigate anxiety on EWT?

  Participants sat in a waiting room believing they were going to take part in a lab study. The low anxiety condition heard a disagreement and then a man left holding a pen. The high anxiety condition overheard a heated argument, crash of equipment then a man emerged holding a bloody knife. Participants were then asked to pick the man out of 50 photos
• What were the results of Johnson and Scotts experiment?

  49% in the low anxiety condition and 33% in the high anxiety condition were able to correctly identify the man
• What were the conclusions of Johnson and Scotts experiment?


  Anxiety decreased the accuracy of EWT, the “weapon focus effect“ describes the findings
• How did Christianson and Hubinette investigate the effect of anxiety on EWT?

  Questioned 58 real witnesses to bank robberies. They were either victims (bank employees) who were directly threatened or bystanders (customers)
• What were the findings to Christianson and Hubinettes research?

  All witnesses showed generally good memories for details, better than 75% accurate recall. Those who where the most anxious had the best recall of all
• What was the conclusion of Christiansen and hubinettes research?


  Anxiety has a positive effect on EWT
• How is the contradicting evidence explained?

  Through the Yerkes-Dodson law
• What is the Yerkes-Dodson law?

  Performance will increase with anxiety, but only to a certain point, after which performance will decrease
• Evaluation - Unusualness not Anxiety:

  • Pickel
  • Carried out experiment using scissors, a handgun, wallet and raw chicken in a hairdressers
  • EWT was poorest in the more unusual conditions (chicken and handgun)
• Limitations of Johnson and Scotts study?


  Ethical issues - deception of participants
• Strength of Christianson and Hubinette?

  Ecological validity - a real life event compared to the artificial event of Johnson and Scott
• Limitation of Christianson and Hubinette?

  The interviews took place a long time after the event so they had no control over confounding variables and post-event discussion