Flashcards in Booklet 2: Eyewitness Testimony Deck (27):
What is eyewitness testimony?
Evidence supplied by people who witness a specific event/crime, relying on their memory.
What is the delvin report?
The psychological study of the accuracy of eye witness recall suggests that it is actually far less reliable than we might imagine. The importance of this issue was highlighted in the Delvin report (1976) which found that in a large proportion of criminal cases, eyewitness testimony was the only eveindece offered in court, and in 75% of these cases the suspect was found guilty. However research in the USA has shown that there may be as many as 10,000 wrong convictions in a year, showing that eyewitness testimony is not reliable.
Who is Elizabeth Loftus?
The leading researcher in EWT. She claims that a persons memory of crime is affected by many things.
What is misleading information?
Often found in form of a question- using words to wrongly imply something has happened so that a witness gives a false testimony. e.g. leading questions.
Describe the procedure of research into misleading information. (Loftus and Palmer)
An sample of 45 american students took part in a lab experiment in which there were 5 conditions (an independent measures design) The were shown a series of 7 films of car accidents. Students were then given a questionnaire about the accidents, which included one specific question about the speed of the cars. Each condition answered a different question 'How fast were the cars going when they ...... each other?' The blank was filled with either the word smashed, collided, bumped, hit, contacted. A week later the participants were also asked if they had seen any non existent broken glass.
Describe the findings of research into misleading information (loftus and palmer)
They found that the condition that used the word smashed led participants to estimate the highest score of 40.8. The participants that were asked with the word contacted estimated the lowest speed of 31.8. A week later they also found that 16% of the participants in the smashed condition had mistakenly seen broken glass, which was considerable more than any other group.
What did loftus and palmer conclude in their research into misleading information?
They concluded that leading questions have a significant effect on eye witness testimony as even if only one word is changed, it will significantly change a persons recall.
What are the main criticisms of research into misleading information?
The main criticism relates to the unrealistic setting and situation of the lab experiment, which could lead to a number of issues:
1. Lack of emotional arousal as its not a real life car crash, it was a video which therefore doesn't create the same emotion as a real crash. In this situation the lack of emotion would make the participants feel less pressure to get the answer right.
2. Lack of usual distraction in real life EWT as the participants were waiting for the video to be played. In real life you would wait for a crash to happen so your full attention wouldn't be focused in the same way.
3. Possibility of demand characteristics as the participants were away they were being studied. Therefore we are unable to see if the results are because of the verbs being changed or because they knew the aim of the study.
What is another problem with the research into eyewitness testimony?
There are problems with the generlisability of the sample as they are all american students so don't represent the entire population. Secondly because they are students, they are less likely to be drivers so are therefore easier to be lead than the average adult. However the research does have a number of important practical implications for real life EWT as it has been used to change the judges system and the way in which witnesses are questioned.
What is the effect of anxiety on EWT?
Anxiety is often associated with witnessing real life crimes and can seriously impact on recall of important features of the situation.
Explain the Yerkes-Dodson inverted U hypothesis.
This has been used to explain how anxiety can affect accuracy of EWT. It shows that a moderate amount of anxiety increases the accuracy of memory up to a point, but after that further anxiety leads to a decline in accuracy.
What is Freud's explanation of anxiety on EWT?
He suggests that it is an ego defence mechanism where the content of traumatic memories is repressed as a way of protecting the mind from emotional stress.
Explain the procedure of research into the effect of anxiety on EWT (Loftus et al - the weapon focus effect)
Loftus suggested that if there is a weapon present at the scene of a crime it may distract attention away from other aspects of the situation. She conducted a lab experiment to test this.
Participants were left in a waiting area outside a laboratory whilst waiting for the real study to start. While they were waiting one of two situations occurred:
1. They overheard a low key discussion in a lab about equipment failure. A person then emerged from the lab holding a pen with grease on his hands.
2. They overheard a heated discussion between people in a lab. After the sound of breaking glass and crashing chairs, a man emerged from the lab carrying a knife with blood on his hands.
The participants were asked to identify the man from a series of photos.
What were the findings of research into anxiety?
The participants in the pen condition had an accuracy of 49% which was considerably higher than in the knife condition where the participants had an accuracy of 33% in recall of the man.
What was the conclusion Loftus made in the anxiety research?
fear of the weapon narrows the witnesses attention to the weapon, thus leaving less attention for other details in the scene.
What are the evaluation points for research into the effects of anxiety?
As the experiment is lab experiment again and therefore an unrealistic setting there are a number of issues:
1. Lack of usual distraction in real life EWT as the participants were waiting for the experiment to start so therefore could of been more accurate.
2. There is a possibility of demand characteristics as it unbelievable so they participants could of been aware of the real aim of the study and therefore been paying more attention.
What supported the criticism of anxiety research?
Research into real life crimes such as Chrisianson & Hubinette:
110 witnesses of 22 real life bank crimes were interviewed sometime after the robberies. They found those who were threatened in some way were more accurate in their recall and remembered more details than those who had been onlookers and less emotionally eroused. This suggests that anxiety producing situations do not always cause reduced EWT.
What are the ethical issues associated with research into anxiety on EWT?
Physical harm, protection from harm, informed consent, deception and right to withdraw.
What has research into the effect of age on EWT suggested?
Some research has suggested that both children and the elderly make poor eyewitnesses however it is important to remember that research in both areas is not always consistent.
Who carried out the research into the effect of age on accuracy of EWT?
Coxon & Valentine (1977)
What was the procedure of Coxon & valentines research?
52 children (8 years), 53 adults (17 years) and 42 elderly (70 years) too part in the study. They were asked 17 questions, after watching a video of a kidnapping. For half of the participants in each age group, 4 of these questions contained misleading information whereas the other half received no misleading information. All participants were then asked 20 questions, 4 of which tested for acceptance of misleading information.
What were the findings of research into the effect of age on EWT?
They found the total number of questions answered correctly was worse in both elderly and children, than in the younger adults. However, on the questions testing for misinformation acceptance, the elderly were less suggestible and were the only age group not to show a statistically significant misinformation effect.
What did Coxon and valentine conclude?
Children and elderly have less accurate recall, so are less valid witnesses.
Eldery are more reliable as they are the least suggestible as they are better at paying attention to detail.
What is another different between the EWT of children and grownups?
Children are more prone to demand characteristics. A met-analysis by Pozzulo (1998) found that children under 5 could reliably pick out a suspect they had seen 2 days earlier from a line-up. However if the target person was not present in the line-up many children still selected an individual and seemed sure that it was the right person. This suggests that children feel pressured into choosing someone from a line- up, not wanting to let the questioner down.
Describe one A02 point for research into the effect of age on EWT.
There is much contradiction because of methodological issues in the research:
There are problems in controlling extraneous variables when comparing different age groups e.g. the people tested may also differ in the amount and type of education they received which may affect the results. Secondly, many of the studies of elderly people use participants from nursing homes who have reduced memory abilities that is not typical for their age group.
Describe a second A02 point for research into the effect of age on EWT.
It is unclear why the age effect occurs. The superior performance of young adults many simply be because they are more motivated and used to being tested. There also problems with own age bias in research as older participants are often compared to college students but on stimuli that is most sited to the college students. For example recognition of faces of young people.