Eyewitness Testimony

• Anxiety


  A normal reaction to a stressful situation which increases heart rate and sweat
• Anxiety


  Lowers accuracy of eyewitness testimony
• Johnson and Scott study


  1. Participants believed they were taking part in a lab study

  2. Participants had to wait in a waiting room

  3. An argument could be heard in the next room
• Low anxiety scenario


  • A man ran past carrying a grease covered pen
• High anxiety scenario


  • A man ran past carrying a knife covered in blood
• 49% of participants were able to correctly identify the man in the low anxiety scenario
• 33% of participants were able to correctly identify the man in the high anxiety scenario
• Participants who saw the knife


  Experienced more anxiety drawing attention away from person holding it
• Anxiety


  Has a negative effect on accuracy of eyewitness testimony
• Johnson and Scott study


  • Numerous ethical guidelines were broken
  • Participants were deceived about the nature of the experiment
  • Participants were not protected from harm
  • Participants were exposed to a man with a bloody knife which may have caused extreme feelings of anxiety
• Johnson and Scott study


  • High ecological validity as participants did not know they were being observed and acted authentically
• Johnson and Scott study

  • Less control over extraneous variables as it was a field experiment
  • Difficult to replicate the study in the exact same way
  • Cannot establish cause and effect