AO1: Key Study: Johnson and Scott (1976)

• Aim:

  To investigate the effects of anxiety and the weapon focus effect on eyewitness accounts.
• Method:

  Laboratory experiment, independent groups design
• Procedure:

  Participants were told to sit in a ‘waiting room’ where they heard an argument from a nearby room. They then saw a man run through the room carrying either a greasy pen or bloody knife. They were then asked to identify the man from a set of photographs. The independent variable was the object in hand (greasy pen and bloody knife) and the dependent variable was the participant’s accuracy when identifying the man they had seen.
• Results:

  33% of participants in the bloody knife condition correctly identified the man compared to 49% of participants in the greasy pen condition.
• Conclusion:

  These findings support the weapon focus effect and suggest that high levels of anxiety have a negative impact on eye-witness accounts.