eyewitness testimony: anxiety

• The procedure of Johnson and Scott study on anxiety having a negative effect.:

  participants sat in a waiting room believing they were going to take part in a lab study. Low anxiety condition was participants heard a casual conversation and then saw a man walk through the waiting room carrying a pen with grease on his hands. High anxiety condition was a heated argument was accompanied by the sound of glass smashing. A man then walked through the room holding a knife covered in blood creating anxiety and weapon focus. They were then asked to pick the man from a set of 50 photographs
• findings and conclusions of Johnson and Scott study on anxiety having a negative effect. 49% of participants in the low anxiety condition and 33% of high anxiety participants were able to identify the man. The tunnel theory of memory argues that people have enhanced memory for central events. Weapon focus as a result of anxiety can have this effect
• Procedure of Yuille and Cutshall study on anxiety having a positive effect. In an actual crime a gun-shop owner shot a thief dead. There were 21 witnesses, 13 agreed to participate in the study. Participants were interviewed 4-5 moths after the incident and the information recalled was compared to the police interviews at the time of shooting. Witnesses also rated howith stressed they felt at the incident
• Findings and conclusions of Yuille and Cutshall study on anxiety having a positive effect. Witnesses were very accurate in what they recalled and there was little change after 5 months. Some details were less accurate like age, weight and height. Participants who reported the highest levels of stress were most accurate (about 88% compared to 75% for the less stresses group). Anxiety doesn’t appear to reduce the accuracy of eyewitness testimony for a real word event and may even enhance it.
• One limitation is that anxiety may not be revealing to weapon focus. Johnson and Scott’s participants may have focused on weapon not because they were anxious but because they were surprised. Pickel found accuracy in identifying the ‘criminal’ was poorest when the object in their hand was unexpected. This suggests the weapons effect is due to unusualness rather than anxiety/threat and so tells us nothing about the specific effects of anxiety on recall
• One strength of anxiety having negative effects is evidence supporting. Valentine and Mesout used heart rate (objective measure) to divide visitors to the London Dungeon’s Labyrinth into low and high anxiety groups. High anxiety participants were less accurate than low anxiety in describing and identifying a target person. This supports the claim that anxiety has a negative effect on immediate eyewitness recall of a stressful event
• One strength of anxiety having positive effects is supporting evidence. Christianson and Hubinette interviewed actual witness to bank robberies, some were direct victims (high anxiety) and others were bystanders (low anxiety). They found more than 75% accurate recall across all witnesses. Direct victims (most anxiety) were even more accurate. This suggests that anxiety doesn’t affect the accuracy of eyewitness recall and may even enhance it