Memory: Factors Affecting Eye-Witness Testimony
LEADING QUESTIONS: A leading question is a question which, because of the way it is phrased, suggests a certain answer. This can distort the accuracy of the eyewitness’ recall because they could imagine details that didn’t happen in the event, just from a certain word or phrase in a question.
LOFTUS & PALMER (1974)
Procedure – 45 participants watched a video of a car crash. Then they were asked how fast the cars were going when the accident happened (e.g. “How fast were the cars going when they hit each other?”). However, for each of the 5 groups, they used a different verb in the question. The words were: hit, contacted, bumped, collided, smashed.
Findings – The mean estimated speed was calculated – contacted: 31.8mph (compared to) smashed: 40.5mph. These results show that a different word/phrase in a leading question can greatly affect the eyewitness’ recall of an event.
POST-EVENT DISCUSSION: Post-event discussion is when eyewitnesses discuss what they saw in an event with each other. This can influence the accuracy of an eyewitness’ recall because the other person’s view could feed them incorrect information.
GABERT et al. (2003)
Procedure – Participants were studied in pairs. They each had to watch a video of a crime but from different points of view, seeing details that the other participant could not. Both participants then discussed what they had seen before individually completing a test of recall.
Findings – The researchers found that 71% of the participants mistakenly recalled aspects of the event that they did not see in the video but had picked up from the other person in discussion. However, the corresponding figure in a control group (where there was no discussion) was 0%. This comparison shows how powerful post-event discussion can be. Gabbert et al. concluded that witnesses often go along with each other, either to win social approval or because they simply believe that the other witnesses are right and they are wrong.
EVALUATION:
A strength of all research into misleading information is that it was hugely important [practical uses in the real world, where the consequences of inaccurate eye-witness testimony can be very serious. (E.g. Loftus thinks that police officers need to be very careful about how they phrase their questions when interviewing eyewitnesses because they can have such a strong effect.) Therefore, research into eye-witness testimony can make an important positive difference to the lives of real people, including the improvement of how the legal system works.
A limitation of Loftus and Palmer’s study is that their participants watched film clips of car accidents, which is very different from actually experiencing a real accident because their anxiety levels won’t be as high. This is a negative because artificial tasks like this may not tell us very much about how leading questions affect eye-witness testimony is cases of real accidents or crimes, suggesting that Loftus and Palmer’s conclusion weren’t very accurate after all.
ANXIETY: It’s not simple to explain the effect of anxiety on eye-witness testimony because accuracy is poor at high and low levels of anxiety but best at moderate levels. However, there has been research into this topic to gives us more information.
YERKES & DODSON (1908) stated that performance with increase with stress, but only to a certain point, where it decreases drastically.
DEFFENBACHER (1983) applied the Yerkes-Dodson Law to eye-witness testimony. He explained that when our anxiety levels are at a medium level (known as optimal level), we are most likely to have more accurate recall of an event, compared to high or low anxiety levels.
WEAPON FOCUS EFFECT: Anxiety can have a negative effect on recall because it prevents us from paying attention to important cues, so recall is worse. An experiment was done to look into this.
JOHNSON & SCOTT (1976)
Procedure – Johnson and Scott led participants into a “waiting room” whilst they heard an argument in the next room. In the ‘low-anxiety’ condition a man then walked through carrying a pen and with grease on his hands. In the ‘high-anxiety’ condition, a man walked through the room with a paper knife that was covered in blood.
Findings – The participants later picked out the man from a set of 50 photos. 49% of them who had seen the man carrying the men could identify him. In contrast, the people who were in the ‘high-anxiety’ condition that saw the blood only had 33% accurate recall. This shows that a witness’s attention narrows to focus on a weapon, because it is a source of anxiety.
EVALUATION:
A limitation of anxiety effects on EWT is that the field studies sometimes lack control. Between the event and the interview many things could have happened to an eyewitness that could’ve altered the accurate recall of the crime – for example, post-event discussions with other eyewitnesses. This means that these extraneous variables may be responsible for how accurate the recall is. The effects of anxiety may be overwhelmed by these other factors, and impossible to assess by the time the participants are interviewed.
As well as this, there are ethical issues in creating anxiety in participants who take part in the tasks. It may subject people to psychological harm purely for the purposes of research. This is why real-life studies are so beneficial – psychologists interview people who have already witnesses a real-life event, so there is no need to create it.
