EYEWITNESS TESTIMONY

EYEWITNESS TESTIMONY

1. Eyewitness testimony: The evidence provided in court by a person who witnessed a crime, with a view to identifying the perpetrator of the crime

   • Post event discussion: Repeat interviewing:Each time the witness is interviewed comments from the interviewer could become incorporated into the recollection of events. Interviewer could use leading questions to alter the individuals memory especially when interviewing children.
   • Post event discussion: Conformity effect: Co-witnesses may reach a consensus view of what actually happened. Pts were in pairs each partner watched a different video of the same event so they viewed unique items. 71% who had discussed the event went in to mistakenly recall items acquired during the discussion.
   • Evaluation: Real world applications: Criminal justice system relies on eyewitness identification for investigating and prosecuting crimes. Mistaken eyewitness identification was the largest factor contributing to the conviction of innocent people.
   • Evaluation: Individual differences: Age differences, An eyewitness typically acquires info from 2 sources observing the event and from subsequent suggestions. Compared to younger people elderly people have trouble remembering the source of the info. They become more prone to the effect of misleading info when giving testimony.

2. Loftus and Palmer leading questions

   • Evaluation: Lacks ecological validity as participants only watched a video clip of the accident. As it was artificial, participants may be less motivated to remember the incident. In real life witnessing a crime is more meaningful and important.
   • Experiment 2: Procedure – A leading question may bias a pt’s response or cause info to be altered before is stored. A new set of pts were divided into 3 groups and shown a film of a car accident lasting 1 minute, and asked questions about speed. The pts were asked to return 1week later, they were asked a series of 10 questions about the accident, including a critical question, ‘Did you see any broken glass?’ There wasn’t broken glass in the film but, those who thought the car was travelling faster might be more likely to think that there would be broken glass.
     • Results – Pts who had estimated a higher speed were more likely to have said they had seen broken glass, as indicated by the findings in the table.
   • Evaluation: type of method used (lab) and its practical applications.
   • Aim - To investigate whether leading questions affects the accuracy of EWT after an event.
   • Experiment 1: Procedure – 45 Pts were shown 7 films of different car accidents. After each film the pts were given a questionnaire asking them to describe the accident then answer a series of specific questions about it. One crucial question concerned the speed of the car on impact. Group 1 got asked ‘How fast were the cars going when they hit each other?’ Other groups were asked the same question but the verb was changed to either ‘smashed’ ‘bumped’, ‘collided’, or ‘contacted’. This critical question was a leading question as it suggested the answer that a pt would give, therefore encouraging them to provide a certain response.
     • Results - The verb used significantly affected speed estimates- Contacted=31.8MPH, Hit=34.0MPH, Bumped=38.1MPH, Collided=39.3MPH, Smashed=40.8MPH Therefore smashed’ produced the highest estimate and ‘contacted’ produced the lowest estimate.
   • Evaluation: Demand characteristics The eye witnesses knew they were taking part in an experiment, may not have taken the task as seriously as if it was real life. Demand characteristics could have effected the pts behaviour, they may have worked out the aim of the experiment and estimated faster speeds in the ‘smashed’ group on purpose. This could make results less valid as they may not be a realistic measure of the effect of misleading info on EWT, so cant generalise findings to real life EWT accounts.

3. Accuracy of eyewitness testimony: anxiety

   • Johnson and Scott
     • Anxiety reduces the accuracy of recall. The view of a weapon in a criminals hand distracts attention (as anxiety is created) form other features which reduces the accuracy of identification.
     • Findings: 49% in identifying the man in the pen condition compared to 33% accuracy in the knife condition. Lotus et al showed anxiety focuses attention on central features of the crime. Researchers monitors the pt's eye movement and found that the presence of a weapon caused attention to be drawn to the weapon and away from the persons face.
     • Procedure: Pts sat in a waiting room where they heard an argument in an adjoining room and then saw a man run through the room either carrying a pen covered in grease or a knife covered in blood. People were later asked to identify the man.
   • Yerkes dodson effect above.
   • Anxiety can improve accuracy: reasearch shows evidence of enhanced recall when they questioned 58 real witnesses to bank robberies in Sweden. They were either victims of bystanders high and low anxiety levels would be shown. Interviews took place 4-15 weeks after. All showed good memories for details of the robbery itself (75% accurate recall) witnesses who were more anxious has the best recall (the victims) so anxiety doesnt reduce accuracy of recall.
   • Evaluation: real life vs lab studies: It was a study of anxiety in context of a real life crime. lab studies may not create real anxiety that would be created in an actual crime.
   • Evaluation: surprise not anxiety: pts watch a thief enter a hairdressing salon carrying scissors (high threat, low surprise) a handgun (high threat, High surprise), a wallet (low threat, low surprise) or a whole raw chicken (low threat, high surprise). Identification was least accurate in the high surprise conditions rather than high threat. weapon focus affect is based on surprise.

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