Factors affecting the accuracy of eyewitness testimony: misleading information, including leading questions and post-event discussion; anxiety.
Interviewing witnesses promptly is thought to be important as events should be fresh in their minds. However, how a witness is questioned initially can be crucial, since research shows that what happens between an event and its recall can later mislead a witness. This is known as the effect of after-the-event-information.
Loftus and Palmer (1975)
Loftus et al. (1978)
Evaluation of Leading Questions
The misinformation may not have replaced the original information as suggested by Loftus. It is possible that instead, the original information is covered by the misleading information so it may still be uncovered to be retrieved again.
- The research lacks mundane realism: What the observers saw in the laboratory would not have had the same emotional impact as witnessing a real life accident. It also differs from real life in that the P’s knew that something interesting was going to be shown to them, and were paying full attention to it. In real life, eyewitnesses are typically taken by surprise and often fail to pay close attention to the event or incident.
- Real Life Implications: This research is important in showing that the memories of eyewitnesses can easily be distorted. However, the main distortion produced in Loftus’ study was for an unimportant piece of information (the presence of broken glass), and it has proved harder to produce distortions for information of central importance (e.g. the weapon used by a criminal).
- Lack of external validity: The participants witnessed brief films, which may have contained much less information than would be available when observing an incident or crime in real life.
Laboratory based research has generally shown impaired recall in high anxiety conditions. In Loftus’s (1979) weapon focus experiment more participants correctly identified a person when they were holding a pen (49%) than when they were holding a knife covered in blood (33%). Loftus and Burns (1982) found participants who saw a violent version of a crime where a boy was shot in the face had impaired recall for events leading up to the incident.
However, in a real life study Yuille and Cutshill (1986) found witnesses who had been most distressed at the time of a shooting gave the most accurate account five months later. Also Christianson and Hubinette (1993) found victims of genuine bank robberies were more accurate in their recall than bystanders.
This relationship states that stress or anxiety increases performance up to an optimal point. After that, further increases in anxiety lead to a falling off of performance. This also seems to apply to the relationship between anxiety and recall.
Weapon Focus – Loftus et al. (1987)
In some ways related to anxiety, it isn’t really surprising that faced with a knife or gun toting maniac you’re most likely be focusing you’re attention on the weapon rather than the attacker. Loftus et al 1987 got participants to listen to a squabble between two people, one sounding more violent than the other. In the quieter affair a man with greasy hands emerges holding a pen. Following the noisy, violent sounding incident a man emerges with a blood drenched knife. Participants could accurately recall the identity of the ‘pen-fiend’ on 49% of occasions but the knifeman on only 33%. They concluded that people’s recall was inhibited by their focus on the weapon (and subsequent anxiety induced by it). In a follow up Loftus recorded eye movements and found the focus of attention was the knife, diverting attention from the identity of the perpetrator.
Real Life EWT & Anxiety – Yuille and Cutshall
Yuille and Cutshall (1986) studied bystanders’ testimonies about a gunfight that took place in Vancouver, Canada, in which a man robbed a gun store and was subsequently killed in a shoot-out between himself and the store owner. Twenty-one witnesses were interviewed by the police within 48 hours of the event, and 13 agreed to be interviewed by researchers four months later. Compared to the police, the researchers asked many more questions about incidental memories, which they were able to verify from other records, such as the colour of the blanket covering the dead gunman. Months after the crime, witnesses’ recall was impressive with distance from the incident producing no difference in accuracy, which was:
- 86 per cent for actions
- 76 per cent for people
- 90 per cent for object[space=10]
Within these figures, however, witnesses who reported being the most upset were the most accurate overall. Analysis of EWT for this real-life event has produced more credible evidence than laboratory studies can and, in this case, has produced different results, possibly because participants’ motivation to recall was more than could be induced by a small payment. There is, however, no control condition, and so cause and effect cannot be established.
Evaluation of Anxiety & EWT
Lack of ecological validity: Laboratory experiments are not very realistic. There is no emotional factor that you get at the site of a real incident and similarly there is no importance in getting the facts right. Foster et al (1994) showed two groups of people a video of a bank robbery followed by an identity parade. Half were told it was part of an experiment whilst the other half were told it was genuine footage and that their answers would influence the trial. This second group were significantly more likely to chose the right culprits from the parade.
Contradictory findings: Laboratory findings have generally found that recall is poor in high anxiety conditions, however studies of real life crimes have found the opposite to be true (such as Yuille and Cutshall, above). This may be due to the lack of ecological validity laboratory studies have in terms of creating real life emotions. Watching a video on a television screen is incredibly different to witnessing a robbery in real life. It is, however, unethical to cause people the anxiety levels of a real crime, in a laboratory setting.