Bartlett’s study showed how our cultural expectations or stereotypes lead to predictable changes in memory. Stereotypes are schemas that summarize large amounts of information. Like schemas, stereotypes influence memory. He argued that schemas affect the retrieval process rather than the initial storage, but a study by Cohen (1981) suggested that schemas and stereotypes are important at both stages of memory: initial storage and retrieval.
The effects of leading questions
An eyewitness’s testimony about an event can be affected by the questions that are asked. For example, if the experimenter asks, “did you see the broken headlight?” rather than “did you see a broken headlight?” the use of the word “the” suggests there was a broken headlight and therefore the participant goes on to build up a memory for that headlight (Loftus and Zanni 1975). The language used in questioning eyewitnesses may alter what they remember.
Loftus and Palmer (1975) showed their participants a series of projector slides of a multiple car accident. The participants then answered specific questions. It was found out that the information implicit in the question affected memory, even though the questions apparently only differed slightly. Loftus later showed that even small differences in the way which a question is asked can have a marked effect.
Memory for faces
Much eyewitness testimony involves identifying a person glimpsed in poor conditions and then recalling their face and/or other characteristics. The data is often incomplete and therefore recall is prone to be influenced by schemas and stereotypes. Under normal conditions, how do people recognize faces? Recognition can be unreliable partly because of the surprise element, nobody necessarily expects to witness a crime and also because of changes in context and appearance. In a brief glimpse, the face of a person is not the main focus of attention. Familiarity is a large part of face recognition. We are more likely to recognize somebody that we know rather than a total stranger.
Bruce and Young (1986) have proposed a model for face recognition which suggests that there are two different mechanisms for familiar and unfamiliar face recognition. There is evidence from the study of brain-damaged patients to support this idea. It has been suggested that the recognition of unfamiliar faces involves feature detection, whereas familiar face recognition involves configural recognition.
The effects of emotional factors of memory
An eye witness will probably be in a high state of emotion at the time the crime is committed, and the psychological evidence suggests this may well influence their recall. Flashbulb memories are created at times of high emotion and many people claim that such memories are very accurate and there is some evidence to support this view. The link between high emotion and flash bulb memory remains unproven but it is still a very popular theory.
When people suffer emotional experiences there recall may not be as good because they may be repressing memories, this goes for crime victims, if they have been involved in some way and they have bad memories of the experience then they may repress these memories and block out some of the data of what actually happened. For this reason hypnosis is often used to try to access memories that cannot be brought to consciousness.
The value of hypnosis
Freud used hypnosis as a means of uncovering the painful memories of some of his clients. However in the end he preferred to use dream analysis to tap the unconsciousness because he found that memories produced under hypnosis were often unreliable, in the sense that it was not clear that the events remembered had actually happened. The media have reported numerous cases in which hypnosis seems to have been effective in bringing forgotten memories to light. The term hypermnesia has been used to refer to the enhanced memory allegedly created by hypnosis.
Part 2 – How can eyewitness testimony be improved?
Geiselman (1985) believed that there should be some changes made to understand and make eyewitness testimony more reliable, and that people should take into account some of the basic characteristics of human memory.
- Memory traces are complex, and contain various features and/or kinds of information.
- The effectiveness of retrieval cue depends upon the extent to which the information it contains overlaps with the information stored in the memory trace, this is the encoding specificity principal.
- Various retrieval cues may permit access to any given memory trace, for example, if the name of an acquaintance cannot be retrieved, it may be recalled if the other information is used as a retrieval cue.
How identity parades are conducted
Identity parades are conducted by police who think they know who the suspect is. They line up a number of people who look similar to the suspect, for example the same height, build, same hair colour or similar facial features and ask the person involved in the crime (the witness) to try to identify who it was they thought they saw at the scene of the crime.
The problem with this method of identification is that there is a large amount of pressure on the victim to pick one person who they think is responsible and this may cause him or her to make false accusations or recall the wrong things because the people in the identity parade all have similar features.
Interview techniques
The home office issued guidelines recommending that police interviews should proceed from free recall to general open ended questions, concluding with more specific closing questions. The basic cognitive interview was also formed after the consideration of the bullet points above, which basically reports on the time of the crime, where it happened, and anything else that they can think of surrounding the incident and then the information is fragmented and ‘picked at’ to find any vital clues or evidence.
Conclusion
There are implications from psychological research for improvements in the collection and use of eye witness testimony. Police might develop the basic cognitive interview by increasing contextual cues to enhance recall, minimising distractions and reducing eyewitness anxiety. Psychologists can be used as expert witnesses in criminal trials to advise jurors on the reliability of eyewitness testimony.
