A03

• Strength of research into misleading information

  It has important practical uses in the criminal justice system
• The consequences of inaccurate EWT can be very serious
• Leading questions


  Can have a distorting effect on memory
• Police officers need to be very careful about how they phrase their questions when interviewing eyewitnesses
• Psychologists are sometimes asked to act as expert witnesses in court trials
• Psychologists can explain the limits of EWT to juries
• Psychologists can help to improve the way the legal system works
• Psychologists can help protect innocent people from faulty convictions based on unreliable EWT
• Practical applications of EWT


  May be affected by issues with research
• Issues with research


  • Loftus and Palmer's PPs watched film clips in a lab, a very different experience from witnessing a real event (e.g. less stressful)
  • What eyewitnesses remember has important consequences in the real world, but PP's responses in research do not matter in the same way (so research PPs are less motivated to be accurate)
• Issues with research


  Suggest that researchers such as Loftus are too pessimistic about the effects of misleading information
• EWT


  May be more dependable than many studies suggest
• Substitution explanation


  • One limitation is that EWT is more accurate for some aspects of an event than for others
  • Recall is more accurate for central details of the event than for peripheral ones
  • Attention was focused on central features of the event and these memories were relatively resistant to misleading information
  • Original memories for central details survived and were not distorted, an outcome that is not predicted by the substitution explanation
• Study


  • Sutherland and Hayne showed PPs a video clip
  • When PPs were later asked misleading questions, their recall was more accurate for central details of the event than for peripheral ones
• Evidence challenging memory conformity


  • Post-event discussion actually alters EWT (Eyewitness Testimony)
  • PPs (Participants) discussed film clips in pairs, each having seen different versions
  • PPs often did not report what they had seen in the clips or what they had heard from the co-witness, but a 'blend' of the 2
• This suggests that the memory itself is distorted through contamination by misleading post-event discussion, rather than the result of memory conformity
• Demand characteristics: Lab studies have identified misleading information as a cause of inaccurate EWT, partly by being able to control variables. But Zaragoza and McCloskey argue that many answers given by PPs in lab studies are due to demand characteristics. PPs usually want to be helpful and not let the researcher down. So they guess when they are asked a question they don't know the answer to.
• Weapon focus effect


  Eyewitness accuracy is significantly poorer when a weapon is present, compared to other objects
• Weapon focus effect is due to unusualness


  Rather than anxiety/threat
• The study by Johnson and Scott may not have tested anxiety, as the reason participants focused on the weapon may have been because they were surprised at what they saw rather than scared
• Pickel's experiment


  • Used scissors, a handgun, a wallet or a raw chicken as the hand-held items in a hairdressing salon video
  • Eyewitness accuracy was significantly poorer in the high unusualness conditions (chicken and handgun)
• The weapon focus effect tells us nothing specifically about the effects of anxiety on eyewitness testimony
• Strength


  Evidence supporting the view that anxiety has a negative effect on the accuracy of recall
• Study supporting negative effects of anxiety on recall


  • Valentine and Mesout study on weapon focus
• Valentine and Mesout study


  1. Carried out in the real-world setting of the Horror Labyrinth at the London Dungeon

  2. Visitors offered reduced entrance fee to complete questionnaire to assess self-reported anxiety

  3. Participants wore wireless heart monitors to confirm experiencing anxiety

  4. Participants divided into high anxiety and low anxiety groups based on 2 measures

  5. Participants' task was to describe a person (actor) encountered in the Labyrinth
• High-anxiety participants


  Recalled fewest correct details of the actor and made more mistakes
• High-anxiety group


  17% correctly identified actor in a line-up
• Low-anxiety group


  75% correctly identified actor in a line-up
• The researchers used an objective measure (heart rate) to divide participants into the high and low-anxiety groups
• In this study, anxiety clearly disrupted the participants' ability to recall details about the actor in the London Dungeon's Labyrinth
• This suggests that a high level of anxiety does have a negative effect on the immediate eyewitness recall of a stressful event
• Positive effects of anxiety

  • Anxiety can have positive effects on the accuracy of recall
• Evidence showing positive effects of anxiety


  • Christianson and Hubinette interviewed 58 witnesses to actual bank robberies in Sweden
  • Some witnesses were directly involved (e.g. bank workers)
  • Some witnesses were indirectly involved (e.g. bystanders)
  • Recall was more than 75% accurate across all witnesses
  • Direct victims (most anxious) were even more accurate
• These findings from actual crimes confirm that anxiety does not reduce the accuracy of recall for eyewitnesses and may even enhance it
• Counterpoint: Christianson and Hubinette interviewed their PPs several months after the event (4-15 months). The researchers therefore had no control over what happened to their PPs in the intervening time (e.g. post-event discussions). The effects of anxiety may have been overwhelmed by these other factors and impossible to assess by the time the PPs were interviewed. Therefore it is possible that a lack of control over confounding variables may be responsible for these findings, invalidating their support.
• Problems with inverted-U theory: The inverted-U theory appears to be a reasonable explanation of the contradictory findings linking anxiety with both increased and decreased eyewitness recall. On the other hand it ignores the fact that anxiety has many elements - cognitive, behavioural, emotional and physical. It focuses on just the last of these (physical arousal) and assumes this is the only aspect linked to EWT. But the way we think about the stressful situation (i.e. cognitive) may also be important
• Support for the effectiveness of the CI: One strength of the CI is evidence that it works. For example, a meta-analysis by Kohnken et al. combined data from 55 studies comparing the CI (and the ECI) with the standard police interview. The CI gave an average 41% increase in accurate information compared with the standard interview. Only 4 studies in the analysis showed no difference between the types of interview. This shows that the CI is an effective technique in helping witnesses to recall information that is stored in memory (available) but not immediately accessible.
• Counterpoint: Kohnken et al. also found an increase in the amount of inaccurate information recalled by PPs. This was a particular issue in the ECI, which produced more incorrect details than the CI. Cognitive interviews may sacrifice the quality of EWT (i.e. accuracy) in favour of quantity (amount of details). This means that police officers should treat eyewitness evidence from CIs/ ECIs with caution
• Cognitive Interview (CI)


  • Not all of its elements are equally effective or useful
  • Using a combination of report everything and reinstate the context produced better recall than any of the other elements or combination of them
• Milne and Bull found that each of the 4 techniques used alone produced more information than the standard police interview