Eye witness testimony

• Factor 1: Leading Questions


  • A leading question is a question that is phrased in a particular (leading) way. The way it is phrased leads the eyewitness to a certain answer. For example, the question "was the knife in the accused's left hand?" suggests that the answer is 'left hand'.
• Loftus & Palmer (1974) experiment


  1. Students watched film clips of car accidents

  2. Given questions about the accident

  3. One critical (important) question (a leading question)

  4. Ps were asked, "about how fast were the cars going when they _________each other?"

  5. Students split into five groups, each received a different question with a different verb (hit, contacted, bumped, collided, smashed)

  6. Mean estimated speed calculated for each participant group
• The verb 'contacted' resulted in the lowest mean estimated speed (31.8 mph) and 'smashed' resulted in the highest mean estimated speed (40.5 mph).
• Response-bias explanation


  The wording of a question has no real effect on Ps memories, but just influences how they decide to answer. When a P hears the word "smashed", this encourages them to choose a higher speed estimate.
• Substitution explanation


  The wording of a leading question actually changes the Ps memory of the film clip.
• Factor 2: Post-Event Discussion


  • Post-event discussion is when witnesses of a crime discuss it with each other. This may lead to their eyewitness testimonies becoming 'contaminated'. This is because they combine their own memories with information from other witnesses.
• Gabbert et al (2003) study


  1. Ps in pairs watched a video of the same crime, but from different points of view

  2. Ps discussed what they had seen with one another before individually completing a test of recall

  3. 71% of the Ps mistakenly recalled aspects of the event that they did not see in the video, but had picked up in the discussion

  4. 0% in control group where there was no discussion
• Normative social influence


  Witnesses go along with one another to win social approval
• Informational social influence


  Witnesses believe the other witnesses are right and they are wrong
• Research into misleading information has increased our awareness of the serious implications that misleading information can have.
• The cognitive interview, a technique that requires special training of police officers to ensure that they prevent the effects of misleading information, has been developed.
• Research is often conducted in the controlled lab environment, allowing researchers to control for confounding variables.
• Researchers often use artificial tasks to investigate, which may not accurately reflect real-life situations.
• Participants may display demand characteristics in artificial environments, over/under exaggerating the effects of misleading information.
• Factor 3: Anxiety


  • Anxiety is a state of emotional and physical arousal. It has strong emotional and physical effects e.g. worried thoughts, tension, increased heart rate.
• Johnson & Scott (1976) study


  1. Ps believed they were going to take part in a lab study

  2. Heard an argument in the next room before a man emerged holding a pen with grease on his hands (low anxiety condition)

  3. Heard glass breaking before the man emerged holding a paper knife covered in blood (high anxiety condition)

  4. 49% in the 'low anxiety' condition were able to identify the man, compared to 33% in the 'high anxiety' condition
• Tunnel theory


  A witness' attention narrows to focus on a weapon because it is a source of anxiety
• Yuille & Cutshall (1986) study

  1. Interviewed eyewitnesses of a real shooting in a gun shop in Canada

  2. Accuracy determined by the number of details reported

  3. Witnesses asked to rate how stressed they had felt at the time

  4. Those who reported the highest levels of stress were most accurate (88% compared to 75%)
• Yerkes-Dodson hypothesis


  The relationship between emotional arousal and performance looks like an 'inverted U'. Lower anxiety produces lower recall accuracy. Memory becomes more accurate as the level of anxiety increases up to the optimal level of anxiety (maximum accuracy). If an eyewitness experiences any more stress than this, their recall declines drastically.
• The enhanced cognitive interview is a technique that police use in order to build rapport with eyewitnesses to crimes to reduce the amount of anxiety they are feeling during the interview.
• Research conducted in controlled laboratory conditions allows for the manipulation of anxiety-provoking situations and the measurement of its effects on recall.
• Cognitive Interview (CI)


  A method of interviewing eyewitnesses to help them retrieve more accurate memories. It uses four main techniques, all based on well-established psychological knowledge of human memory – report everything, reinstate the context, reverse the order, and change perspective.
• Cognitive Interview (CI)


  • Report everything
  • Reinstate the context
  • Reverse the order
  • Change perspective
• Schema


  A cognitive framework that helps organise and interpret information in the world around us
• Enhanced Cognitive Interview (ECI)

  Includes additional elements to focus on the social dynamics of the interaction, such as reducing eyewitness anxiety, minimising distractions, getting witnesses to speak slowly, and asking open-ended questions