Factors affecting accuracy of EWT: misleading information

• Eyewitness testimony is a legal term given to the use of eyewitnesses in court to give evidence for the identity of someone who has committed a crime.
• One of the main factors that affect the accuracy of EWT seems to be what happens after the event. The memory from the events are fragile and can be easily changed by post event information. Having someone introduce a new idea can make the person believe that really happened.
• Misleading information is information given to the eyewitness usually after the event and it includes LEADING QUESTIONS and POST-EVENT DISCUSSION between co-witnesses and/or other people.
• A leading question is a question, which because of the way it is phrased, suggests a certain answer e.g. “Was the perpetrator holding a knife in their right hand?”.
• Post-event discussion occurs when there is more than one witness to an event. Witnesses may discuss what they have seen with co-witnesses or with other people. This may influence the accuracy of each witness’ recall of the event.
• Post-event discussion occurs in two ways:

  • conformity effect: witnesses discuss event after it happened leading to false memories as they reach a consensus about what happened
  • repeat interview: witnesses are interview many times and asked the same questions so information from interviews leads to demand characteristics.
• Loftus and Palmer second study into leading questions:

  • Method: participants watched video of a car crash, then were asked “How fast the cars were going when they […]?”. 3 groups of participants: group 1 given the word smashed, group 2 given the word hit, group 3 weren’t asked this question. After one week participants were asked if they saw any broken glass. 
  • Results: group 1 who were given the word smashed are more likely to say that they had seen broken glass 
  • Conclusion: substitution explanation - means that the wording of a question changes the participants memory of the film clip.
• Loftus and Palmer first study into leading questions:

  • Method: participants watched a video of a car crash, then were asked “How fast the cars were going when they [verb]?”. There were 5 groups of participants: each were given a different verb in the question the verb could be either hit, smashed, bumped, contacted or collided. 
  • Results: participants tend to give higher speeds when the word smashed was used (41 mph on average), while contacted had the lowest average speed (32 mph on average).
  • Conclusion: leading question biased the eyewitnesses’ recall of the event
• Gabbert et al studied PED:

  • Method: 2 groups of ppts: control group watched a video of a girl stealing a wallet individually, 2nd group of ppts were in pairs and watched the video of the same crime but from different points of view. The 2nd group were then allowed to discuss. 
  • Results: 71% of ppts in experimental group recalled information that they had not actually seen but picked up in discussion, while 0% of control group did this. 
  • Conclusion: ppts in experimental group were influenced by PED - may have wanted to win social approval or thought they were wrong (memory conformity).
• A strength of research into the effect of misleading information on eyewitness testimony is that it has real-life application. This is because Loftus (1975) believes that leading questions can have such a distorting effect on memory that police officers need to be careful about the way they phrase questions. Therefore this strengthens research into the effect of misleading questions on EWT as its findings can be used to improve the way the legal system operates and improve the accuracy of EWT so the right suspects are identified as perpetrators.
• A weakness of research into the effect of misleading information on eyewitness testimony is that most of the research occurs in a lab setting and uses artificial stimuli in their investigations, for example, Loftus and Palmer. This is a problem as an artificial setting and the use of artificial stimuli which doesn’t have meaning to the participants, may not give an accurate depiction of EWT. This weakness research into the effect of misleading questions on eyewitness testimony as the problem of demand characteristics limits the reliability and validity of the results.