EWT: Anxiety

• Johnson + Scott's study:

  • field experiment, independent group design
  • self-selected sampling
  • participants put in waiting room
  • low anxiety: casual conversation, saw a man holding a pen
  • high anxiety: heated arguments + man with a bloody knife
• Anxiety can be positive:

  • Creates a physiological arousal - fight/flight response which creates alertness
• Yuille + Cutshall: Procedure:

  natural experiment

  • actual shooting in gun shop, Toronto
  • shop owner shot a thief and killed him
  • 21 witnesses and 13 took part
  • participants were interviewed after 4-5 months
  • compared these interviews to original police interviews
  • accuracy based on number of details reported in each interview
  • rated stress from 1-8
  • reported any emotional disturbances
• Yuille and Cutshall: Findings:

  • little change in accounts
  • some details = less accurate
  • high stress levels = more accurate = 88%
  • shows anxiety can improve accuracy of recall
• Yerkes and Dodson:

  • They said that the relationship between emotional arousal and performance looks like an inverted U
  • If arousal is too low or high performance will be lower
• LImitation of anxiety as a negative effect: Johnson and Scott may not have tested anxiety:

  • Pickel - conducted an experiment using scissors, handgun, wallet or raw chicken
  • Eye-witness accuracy was much poorer in the high unusualness conditions
  • Suggests weapon focus effect is due to unusualness
• Strength of negative effects of anxiety: Supporting study:

  • Valentine and Mesout supports weapon focus
  • used heart-rate to divide participants into high and low anxiety groups
  • high anxiety disrupted recall details about the actor in the London Dungeon
• Strengths of anxiety: Positive effects: Research support

  Christianson and Hubinette

  • 58 witnesses to actual bank robberies
  • recall was more than 75% across all witnesses
  • The direct (most anxious) had the highest recall rates