Another theory for this reduction in recall could be List’s idea of high and low probability in EWT. List asked a group of people to rate what probability different events had in a shoplifting scenario; she then showed each incident as a video to different participants, and one week later tested their recall. List found that people remembered high probability events better. However they included more errors and described events that had not actually occurred, they used their schemas. This may be because high probability events had already become related to the participant, this (according to research) makes it easier to remember, but prior experience can distort the facts.
The defence or prosecution can easily manipulate a witness on a stand because he may use leading questions to warp the witness’ memory of an event. Loftus and Palmer researched this effect by showing participants a video of a car crash and asking them to estimate to speed of the car. They were divided into groups and each asked a slight variation of the same question:
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How fast were the cars going when they Contacted each other?
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How fast were the cars going when they Hit each other?
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How fast were the cars going when the Smashed each other?
It was found that this word affected the speed estimation. There was roughly 10mph difference between the contacting cars and the smashing cars. One week later, those in the “smashed” group consistently reconstructed their memories to include broken glass. However, there is very low ecological validity in this experiment, it has confounded variables such as age and gender, and the stress levels of the participants. It also has the possibility of having demand characteristics due to the groups, people will not want to be abnormal and not go along with the group’s answer (Levels of conformity). Conformity can influence EWT as people want to give answers that are “acceptable” to their peers, known as Normative influence, or when unsure, a participant can look to other members of the group for guidance and assurance, (informational influence).
Other leading questions can be very sly and subversive such as
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Did you see a broken headlight?
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Did you see the broken headlight?
If there was a broken headlight, most people would answer truthfully, but where there wasn’t any broken lights, participants would say yes twice as often when the was used over A. This experiment coincides with the evidence above.
Due to these findings that EWT can be deceiving, psychologists research ways to make the testimonies more reliable. One of these ways is through Cognitive Interviews developed by Geiselman et al in 1985. The technique is based on four major instructions;
- To recreate the context of the incident: to try to recreate smells, emotions, weather and so on. This prevents reconstruction memory.
- To report every detail: details that the witness may not believe relevant. This makes it hard to ask leading questions.
- To recall the event in different orders: the witness is asked to recall details from the end of the incident to the beginning and from a main even to the end and visa versa, this can prevent the witness from rehearsing confabulated and incorrect memories.
- To change perspectives: The witness is asked to try and describe the event from another’s perspective. Again this prevents leading questions.
Geiselman et al compared their results against real police interviews using incorrect items recalled and invented items, against number of correct items. The result was that there were 25% more correct answers using the cognitive interview. This experiment can be criticized on its artificiality, as the researchers used videoed incidents, not actual witnesses.
To support EWT Foster et al researched the idea of consequences to the witness’ testimony. They showed two groups of participants the same video of a robbery, and then asked the participants to pick the robber out of a line up. Foster told one group that it was a real robbery and that their choice would affect the trial, the other group assumed it was a simulation. The group who felt the consequences of their actions made fewer mistakes. This creates doubt for lab experiments into EWT due to their lack of ecological validity. Christianson and Hubinette researched “real-life” witnesses. Victims, (rather than onlookers) could recall details very accurately and still had good recall after 15 months. This evidence helps to prove Loftus’ theory that proximity and having powerful emotions can have a very positive effect on EWT.
In conclusion, although there is a large quantity of research into the fallibility of eyewitness testimonies, all of which viable and not without merit, however the artificiality of the majority of the experiments make it hard to prove them true. Many confounding factors may have an impact on a testimony in “real-life” such as stress, panic, fear, eye sight, visibility due to smoke/rain/distance from the incident, intoxication, novelty factor, time lapse between event and testimony, social desirability, the desire to please the interrogator, interference, and how much responsibility comes with giving the testimony. The Flashbulb Memory model also has influence here and is apparent in Christianson and Hubinette’s research, as most witnesses to violence or crime can remember it as though taking a “photograph” and can remember the smells and colours for years.