eyewitness testimony Flashcards
what is eyewitness testimony
where a person who was present at an event recalls what happened. It is often used as evidence in court but eyewitness can be unreliable
factors affecting the accuracy of eyewitness testimony
misleading information
anxiety
misleading information
accuracy of eyewitness testing can be altered after the event by exposing the witness to misleading information during post event discussion
procedure and findings of misleading information
loft and parmer (1974) conducted a study.
45 participants were shown the same video clips of car crash. the particpients were divided into 5 groups and they were all asked the same question with different verb used each time.
The more intensive verbs rather than least influenced the participant to estimate a higher speed. This shows that leading can affect eyewitness testimony.
anxiety
Another factor affecting eyewitness testimony is the witness’ anxiety levels. This is particularly relevant when witnesses are recalling anxiety-inducing events, such as violent crimes.
deffenbacher
(1983)
suggested an inverted u hypothesis. Moderate amount of anxiety produces the most accurate. However, to little or too much anxiety reduces the accuracy of eyewitness testimony
limitation of inverted u hypothesis
chrisianson and Hubinette found no relationship between anxiety and accuracy of testimony
limitation of misleading info
One limitation of the substitution explanation is that EWT is more accurate for aspects of an event than for others. For example Sutherland and Hayne showed participants a video clip. When participants were later asked misleading qs, their recall was more accurate for central details of the event than for peripheral ones. Presumably the participant’s attention was focused on central features of the event and these memories were relatively resistant to misleading info. This suggests that the original memories for central details survived and were not distorted, an outcome that is not predicted by the substitution explanation.
Another limitation of the memory conformity explanation is evidence that post event discussion actually alter EWT. Skagerberg and Wright showed their participants film clips, There were 2 versions e.g a muggers hair was dark brown in one but light brown in the other. Participants discussed the clips in pairs, each having seen different versions. They 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, so the common answer was not light brown or dark brown but medium brown. This suggests that the memory itself is distorted through contamination by misleading post event discussion, rather than the result of memory conformity.
Improving the accuracy of eyewitness
The Cognitive interview
P - Change in perspective
R - report everything
O - change order
M - Mental reinstatement
mental reinstatement
CL is when the interviewer encourages the interviewee to mentally recreate physical and psychological environment of the original incident.
report everything
witness is encouraged to report all the details even if they seem irrelevant. As memories are interconnected, so may provide cues allowing to trigger further info.
Change order
recalling the event in a different order, which would also increase the accuracy of testimony by reducing the effect of the witness’ schema
Change Perspective
Recreate the event from anothers perspective, also increase the accuracy of eyewitness testimony by reducing the effect of the witness’ scheme
A03:
strength of Cognitive Interview
One strength of the cognitive interview is evidence that it works. For example, a meta analysis by kohnken et al combined data from 55 studies comparing the CI with standard police interviews. The CI gave an average 41% increase in accurate info compared with the standard interview. Only 4 studies in the analysis showed no difference between the types of interview. This shows that CI is an effective technique in helping witness to recall information that is stored in memory but not immediately accessible.
A03:
limitation of Cognitive Interview
One limitation of the original CI is that not all of its element are equally effective or useful. Mine and Bull found that each of the four technique used alone produced more info than standard police interview. But they also found that using a combination of report everything and reinstate the context produced better recall than any of the other element or combination of them. This confirmed police officers suspicions that some aspects of the CI are more useful than others. This casts doubt on the credibility of the overall cognitive thinking.
Another limitation is that police officers may be reluctant to use the CI because it takes more time and training than the standard police interview. For example more time is needed to establish rapport with a witness and allow them to relax. The CI also requires special training and many forces do not have the same resources to provide more than a few hours. This suggests that the complete CI as it exists is not a realistic method for police officers to use and it might be better to focus on just a few key element.
Cognitive interview
Fisher and Gelselman argued that eyewitness testimony could be improved if the police officer used better techniques when interviewing witness. Fisher and Gelselman recommended that such techniques should be based on psychological insights into how memory works and called these technique collectively the cognitive interview to indicate its foundation in cognitive psychology. These are 4 main techniques that are used.
