Eye witness testimony and anxiety

• What is the weapon focus effect


  The presence of a weapon to draw attention and impair a witness's ability to identify the culprit. Violent acts will increase anxiety in a witness.
• Explain Johnson and Scotts experiment


  PPS were seated in a waiting room ready to take part in what they thought was a lab study. They overheard a heated argument in the next room. 2 conditions included: A man emerging with a pen and grease on his hands (equipment error) or a man emerging with a paper knife covered in blood. PPS were then asked to identify the man.
• What were the results of Johnson and Scotts experiment


  In the low anxiety condition - 49% identified the correct man

  In the high anxiety condition - 33% identified the correct man
• Explain the alternative theory - biology

  The anxiety a witness experiences triggers a stress response within the body that activated fight or flight. Our brain becomes hyper alert and memory capacity improves because of our psychological state.
• Explain Yuille and cutshalls experiment


  Interviewed 13 eye witnesses to recall a real life shooting involving a shopkeeper and an armed thief. The shopkeeper was wounded but recovered, and the thief was shot dead.
• What were the findings of Yuille and cutshalls experiment


  Witnesses gave an impressively accurate account 5 months later.

  Witnesses closest to the incident gave the most detail.

  Witnesses who were most distresses were most accurate.
• Explain Christianson and Hubinettes experiment


  Questioned 110 witnesses who had seen a total of 22 bank robberies. Staff (victims) gave a more accurate account than bystandars.
• Explain the Yerkes-Dodson Law


  The principle that performance increases with anxiety only up to a point, beyond which performance decreases

  
• Explain pickles theory

  The more unusual the object involved, the less accurate the EWT. For example a rubber chicken is usually worse than a gun.
• Explain the issue with lab studies


  Lab studies have high demand characteristics, impacting validity.