Another factor that may affect the reliability of eyewitness testimony relates to identity parades. The number of people within a line-up who are similar to the suspect can affect the chances of correct information. This is referred to as the functional size of the line-up. Doob & Kirshenbaum (1973) reported the case of Ron Shatford. Following a robbery the witness described the robber as ‘neatly dressed and good-looking’. Shatford was arrested a placed in a line-up with eleven unattractive men. He was then convicted of the robbery. However fifteen months into Shatford’s sentence another man confessed to the robbery. Also it is important for the witness to be told that the suspect might not actually be in the parade. Wells (1993) pointed out that if the police fail to do this, the witness feels that they must make a positive identification, as they believe that the police would not have set up an identification parade unless they were fairly certain that the culprit is present. So the person that is the closest match to their memory is picked. Finally Lindsay et al (1991) as cited by Eysenck and Keane (2000) suggests that presenting the suspects one at a time reduces the probability of mistaken identity. This is known as a sequential line-up. It reduces the effects of functional size and helps the witness to see if the suspect isn’t there.
The work of Bartlett (1932) on reconstructive memory as cited by Broome (1991) suggests that recall is subject to distortion by the witness’ prior knowledge and expectations. We tend to see and in particular interpret and recall what we see according to what we expect and assume is ‘normal’ in a given situation. These assumptions may be determined by social values and therefore prejudice. This is also known as confirmation bias. An example stated in Eysenck and Keane (2000) found that when students from two universities were shown a film of a football game involving teams from both universities, the students showed a strong tendency to report that the opponent team had committed more fouls. Cohen (1966) as cited by Gross (2000) showed that faces are not seen in isolation but that they are perceived or influenced by both the event itself by people’s social norms and values and therefore stereotyped images.
Cohen suggested that people find it easier to identify people from their own race than people from a different race. This is reflected in the statement ‘They all look the same!’ He referred to this as Cross-Race Identification Bias. Cohen illustrated this by asking shop workers in Texas to identify customers of three different races that had purchased something from the shop that day. The accuracy of their recall was different for customers of different races and was related to the race of the shop workers. Therefore when an eyewitness and a possible suspect are from different races the identification of the suspect must be treated with caution. Cohen also points out that it is difficult to recognise people out of the context which you would ordinarily have contact with them, ‘Its hard recognise your bank manager at the disco or your dentist in evening dress’ (Cohen).
The presence of a weapon can also affect the reliability of an eyewitness account. It is suggested that if an eyewitness, witnesses a crime in which a weapon is present they tend to focus on the weapon and are less likely to correctly identify the suspect. This is known as the weapon focus affect. A meta-analysis by (Olson and Wells 2003, p. 282) ‘indicates that the presence of a weapon reduces the chances that the eyewitness can identify the holder of the weapon (Steblay 1992). Loftus et al. (1987) monitored eyewitnesses’ eye movements and found that weapons draw visual attention away from other things such as the culprit’s face. Complicating the issue somewhat is the fact that the presence of weapons or other types of threatening stimuli can cause arousal, fear, and emotional stress. The effects of such stress on memory are still being debated. Some research shows that an increased level of violence in filmed events reduces eyewitness identification accuracy (e.g., Clifford & Hollin 1981) whereas other research has failed to find this effect (e.g., Cutler et al. 1987)’.
There is a theory that recall is easiest if it takes place in a similar environment or when the witness is at the same emotional level. As most people are shocked, scared or disturbed when witnessing a crime at first hand, this may make recall harder when witness have calmed down are quietly being asked questions. The more serious the crime, the more pronounced this affect may be. Loftus and Burns (1982) as cited by Broome (1991) suggest that a witness is likely to be less perceptive when in frightened or emotional state.
Clothes and disguises also have an affect on eyewitness’s recall. Buckhout (1984) suggested that in brief encounters people tend to focus on features such as clothing and hair, because they are far more visible and witness can easily disguise between different types of them. ‘Simple disguises, even those as minor as covering the hair, result in significant impairment of eyewitness identification.’ (Cutler et al.1987). These however are the simplest to change. A culprit within an identity parade can dress differently than when they committed the crime, which can throw witnesses of the scent. Also if there is a person in the parade wearing similar clothes to what the culprit was wearing at the time of the crime then they can be mistakenly identified as the culprit. This is also the case for hair colour.
Distinctive faces are much more likely to be accurately recognized than non-
distinctive faces (e.g., Light et al. 1979). Faces that are highly attractive or highly unattractive are easier to recognize than are faces that are average in attractiveness (e.g., Fleishman et al. 1976) as cited in (Olson and Wells 2003)
The age of the eyewitness is another factor linked to eyewitness identification performance, with very young children and the elderly performing significantly worse than younger adults. When the lineup contains the actual culprit, young children and the elderly perform nearly as well as young adults in identifying the culprit, but when the lineup does not contain the culprit the young children and the elderly commit mistaken identifications at a higher rate than young adults do. Children are generally more prone to suggestion and memory distortion.
The Cognitive interview developed by Geiselman et al (1985) has been introduced to help eyewitness recall events accurately. It is based on four basic principles:
- To reinstates the environmental and personal context of the crime in the mind of the witness. This includes sights, sounds, smells, feelings and emotions.
- To have the witness report every single detail even if they believe it to be trivial.
- To recall the event in a different order
- To try to report the incident from other participants perspectives
Geiselman et al (1985) used a laboratory study to compare the cognitive interview to a standard police interview in gaining information bout a crime they had watched on video. The standard interview group provided on average 29.4 correct answers compared to an average of 41.1 correct answers by the cognitive interview group.
Fisher et al (1987) cited by Eysenck and Keane (2000) developed an 'enhanced cognitive interview’ which used the same techniques plus the emphasising the use of open questions, reducing anxiety and tailoring language to suit the individual witness. Fisher found that eyewitnesses produced an average of 57.5 correct statements when given the enhanced interview, compared with 39.6 with the basic interview. When applied by the police in Miami it was found to produce 46% increase in details recalled at an accuracy level of 90% (Fisher1990).
It is my opinion that on the whole, eyewitness testimony is prone to corruption and distortion. The majority of studies whose results are counterintuitive undermined the reliability of eyewitness testimony. I therefore feel that the testimony of a witness should be carefully considered within a trial and the reliance upon it should be lessoned.
References
Broome, D (1999). Introduction to Cognitive Psychology. Sussex: Psychology Press Ltd.
Doob, A. N. & Kirshenbaum, H. M. (1973). Bias in police line-ups — partial remembering. Journal of Police Science and Administration, 18, 287-293.
Eysenck, M.W. and Keane, M.T. (2000) Cognitive psychology 4th Edition. Sussex: Psychology Press Ltd.
Geiselman, R.E., Fisher, R.P., MacKinnon, D.P. and Holland, H.L. (1985). Eyewitness memory enhancement in police interview: Cognitive retrieval mnemonics versus hypnosis. Journal of Applied Psychology, 70, 401-412.
Gross, R. (2001). Psychology: The Science of Mind and Behaviour 4th Edition. London. Hodder & Stoughton Ltd.
Loftus, E.L. and Palmer, J.C. (1974). Reconstruction of automobile destruction: An example of the interaction between language and memory. Journal of Verbal Learning and Verbal Behaviour, 13, 585-589
Olson, E.O. and Wells, G.L. (2003). Eyewitness Testimony. The Annual Review of Psychology, 54, 277-295
Wells, G. L. (1993). What do we know about eyewitness identification? American Psychologist, 48(5), 553-571.
Yuille, J.C. and Cutshall, J.L. (1986). A case study of eyewitness memory of a crime.
Journal of Applied Psychology, 71, 291-301