However some psychologists have argued that all forgetting is cue-dependant forgetting. They believe that we store all or almost all information permanently somewhere in long-term memory even if it cannot be retrieved.
- Outline and evaluate research (theories and/or studies) into eyewitness testimony (EWT).
Eyewitness testimony is evidence supplied by people who witness a specific event or crime, relying only on their memory. Their statements often have to include descriptions of the criminals facial appearance, other identifiable characteristics, and details of the crime scene (e.g. the sequence of events, time of day, and if others witnessed the event, etc). There is good evidence that eyewitness testimony can be false, as eyewitness memories of events tend to be fragile and easily distorted (e.g. by leading questions).
In 1979 a study was carried out by Wells, Liepe, and Ostrom. They set up a cubicle where participants were told to wait before the study started with a calculator in it, whilst each participant waited a confederate of the experimenter appeared and put the calculator into her purse. When the participants were asked to identify the “thief” from a set of pictures, only 58% were correct. More worryingly however when the same participants were asked to “testify” at a mock trial, the jury believed 80% of them.
There are a large number of explanations as to why eyewitness testimony is so unreliable. For example, people often fill in gaps in their memory with what they think may have happened if they don’t have total recall for an incident. This is called reconstructive memory and depends on the persons stereotypes e.g. you may not expect an old woman to commit a crime so you may “recall” that it was a man instead. As well as reconstructive memory the effect of language is also an issue, as the wording of questions asked to the eyewitness may lead them to give certain answers.
In 1932 Bartlett undertook a study of reconstructive memory, he asked English participants to read a North American Indian folk tale “The War of the Ghosts”, after reading the story the participants were asked to recall it. The participants recall changed the content and style of the original story. The story was shortened and phrases changed to be more similar to our own language and concepts. The participants were asked to recall the story many times, even a year later. The changes increased over consecutive recalls. Most of the recalls distorted the story to make it more English therefore making it more clear and logical.
Bartlett’s research is significant because it provided some of the first evidence that what we remember depends on our prior knowledge (schemas). Bartlett used stories from an unfamiliar culture to show good evidence of methodical distortions in memory. However Bartlett’s approach to his research lacked objectivity. Some psychologists believe that only well-controlled experiments will produce objective data. Bartlett’s methods were quite casual; there were no special conditions for the participants’ recall so it is possible that other factors effected it such as the conditions around them when they were recalling the story. It could also be that the changes to the story were simply guesses by participants who were trying to make their recall seem more understandable and complete rather than genuine distortions in their recall.
In 1974 Loftus and Palmer formed a sample of 45 students to show how the wording of a question could distort memory of an event. They showed their participants a short film portraying a car accident involving a number of cars. They were then asked to describe what had happened as if they were an eyewitness. After they had watched the film the participants were asked fixed questions, including the question "About how fast were the cars going when they (hit/smashed/collided/bumped/contacted) each other?” The independent variable was the wording of the question and the dependant variable was the speed reported by the participants. A week after the participants were shown the film of the car accident they were asked, “Did you see any broken glass?” however no broken glass was shown in the film. Loftus and Palmer found that estimated speed was influenced by the verb used. The verb suggested information about the speed, this systematically affected the participant’s memory of the accident. Those who were asked the question where the verb used was “smashed” believed that the cars were going faster than those who were asked the question with “hit” as the verb. The mean estimate when “smashed” was the verb was 41mph versus 34mph when “hit” was used. In answering the question about broken glass, a larger percentage of the participants who heard the verb “smashed” said they had seen broken glass (32%) than those who heard “hit” (14%). This research lacks mundane realism, as what the participants saw in the laboratory wouldn’t have had the same emotional impact as witnessing a real life accident. It also unlike real life as the observers knew something interesting was going to be shown to them, and so were playing full attention to it. In everyday life witnesses are taken by surprise and often fail to pay close attention to the incident. The research is important in proving that memories of eyewitnesses can be easily distorted, but the main distortion in this study was for a relatively insignificant piece of information, it has proved harder to produce distortion for information of more central importance.
Although the mass of studies show that eyewitness testimony can be unreliable and can be distorted, there have been studies showing real life recall can be very accurate. A study by Yuille and Cutshall in 1986 showed this, Yuille and Cutshall interviewed people who had witnessed a crime where one person was shot dead and one person fatally injured. These interviews which were carried out a number of months after the incident had taken place, along with the interviews given to the police immediately after the incident, were analysed. The eyewitness accounts were found to be very accurate, and the accuracy and amount of information recalled didn’t decrease over time. The eyewitnesses’ accounts also didn’t become distorted by leading questions.
The Devlin report in 1976 to the Home Secretary found that in 1973 there were 850 cases where eyewitness testimony was the only evidence of guilt. In 74% of these cases a jury found the accused guilty. Because of the findings already discussed the Devlin committee advised that no jury convict on eyewitness testimony alone.
