Eye witness testimony

• leading questions

  Loftus and Palmer 1974 arranged for participants to watch film clips of car crashes and then gave them questions about the accident. ‘About how fast were the cars going when they HIT each other’ ‘hit’ suggests the speed of the car was going.

  Mean estimated speed was calculated for each group, contacted- 31.8mph, smashed- 40.5
• The response bias explanation of leading questions

  The wording of the question has no real effect on the participants memories, but just influences how they decide to answer. When a participant gets a leading question using the word ‘smashed’, this encourages them to choose a higher speed estimate
• substitution explanation of leading questions

  Loftus and Palmer- the wording of a leading question actually changes the participants memory of the film clips. Those who heard ‘smashed’ reported seeing broken glass more than those who heard ‘hit’.
• Post-event discussion

  Gabbert 2003 studied participants in pairs, each participant watched a video of the same crime but filmed from a different points of view. Each participant could see elements of the event that others could not, they discussed what they saw before completing a test of recall individually. 71% recalled the events that they didn’t see in the video, the control group who didn’t discuss what they saw had 0%
• Evaluation- real-life application

  +Loftus 1975 believed they can have a distorting effect on memory so that police officers needed to be very careful about how they phrased their questions when interviewing eyewitnesses. Can be used to improve the legal system
• Evaluation- artificial tasks

  -the video clips lack the same stress as a real-life situation. Use of such artificial tasks may tell us little about how leading questions affect EWT in cases of real accidents or crimes
• Evaluation- individual differences

  -Older people are less accurate than younger people when giving eyewitness reports. Anastasi and Rhodes 2006 found that people in groups 18-25, 35-45 were more accurate than 55-78.
• Evaluation- demand characteristics

  -Zaragosa and McCloskey 1989, lab studies give demand characteristic. Participants do not want to let the researcher down and want to appear helpful and attentive. May answer the question how they believe they should not how they actually think
• What is anxiety and its negative impact on recall?

  It creates physiological arousal in the body which prevent us from paying attention to important cues
• Anxiety has a negative impact on recall- weapon focus

  Johnson and Scott 1976, the participants believed they were in a lab study. They were seated in a waiting room, in the low-anxiety condition- heard a casual conversation in the next room and then saw a man walk past them with a pen in his greasy hands. In the high-anxiety condition- overheard a heated argument, with the sound of breaking glass, a man walked out with a bloody knife. They then had to identify him from pictures - 49% in LA could identify him, 33% in HA could identify him.
• Anxiety has a positive impact on recall

  Yuille and Cutshall 1986 conducted a study of an actual shooting in a gun shop in Canada, the thief shot the owner dead. 21 witnesses and 13 took part in the study. Interviewed 4-5 months later and compared the result to the original police statement, accuracy was measured by the amount of details remembered. Asked to rate how stressed they felt at the time of the incident and whether they had any emotional problems from it.
• findings of the positive impact research

  The witnesses were very accurate in their accounts and there was little change in the amount recalled or accuracy after 5 months. Those who reported the highest stress levels remembered the most
• Evaluation- unusualness not anxiety

  -Johnson+Scott The participants may have been shocked at what they saw rather than scared. Pickel 2998- eyewitness accuracy was significantly poorer in the high unusualness conditions
• Evaluation- research support

  +j&S - Valentine and Mesout 2009 supports the research on weapon focus, finding negative effects on recall. Measured heart-rate in LA and HA conditions, anxiety clearly disrupted the participants ability to recall details about the actor
• Explaining the contradicting research in anxiety

  Yerks and Dodson 1908- the relationship between emotional arousal and performance looks like an 'Inverted U'.
• Testing Yerkes-Dodson Law

  When we witness a crime we become emotionally and physiologically aroused. We experience anxiety and fight or flight. Lower levels of arousal produce lower levels of recall accuracy and then memory becomes more accurate as the level of anxiety increases. There is an optimum and maximum level of anxiety
• Evaluation for positive effect - supportive evidence

  +Christianson 1993 interviewed 58 witnesses in an actual bank robbery in Sweden. Those directly involved and indirectly involved were interviewed. Recall was 75% across all witnesses and was more accurate in direct group.
• evaluation for positive effect- problems with inverted-U theory

  -It ignores that anxiety has many elements-> cognitive, behavioural, emotional and physical. It only focuses on the physical aspects - physical arousal and assumes this is the only aspect of EWT involved. the way we think about the stressful situation may also be important