Eyewitness Testimonies in the Legal Setting
Royal Melbourne Institute of Technology
Eyewitness testimony is an important area of research in cognitive psychology and human memory. Matsumoto, 2009 defined eyewitness testimony as information that an individual can provide about a crime. This includes information about the perpetrator(s) as well as information about the crime and crime scene. This information is then delivered by the bystander in a courtroom, where the jury must pay special attention and may even come to a decision based on this, somewhat reliable piece of evidence. Eyewitness testimonies’ have been considered a credible source in the past, but have recently come under attack as forensics now support psychologists in their claim that memories and individual perceptions are unreliable; as they are easily manipulated, altered, and biased. Research into this area has found that eyewitness testimony can be affected by many psychological factors including anxiety and stress, reconstructive memory and also the use of leading questions.
One factor that is thought to have a significant effect on eyewitness memory is the degree of emotional arousal or stress experienced by the witness during the crime. There are many studies looking at the effects of anxiety and stress on eyewitness testimonies’. Some of them have shown that anxiety can impair the accuracy of these testimonies. However, other studies have proven that anxiety and stress can actually lead to a more detailed and accurate recall of the event witnessed. Loftus and Burns (1982) showed that anxiety can impair the accuracy of eyewitness testimonies. One group of participants were a showed a film of a crime with no violence. Another group were shown the same film but with a violent incident where a boy was shot in the face. They found that those who saw the violent incident recalled significantly less than those who saw the film without the violent incidence (“As Psychology”, 2010). In another study, Christianson and Hubinette (1993) demonstrated that witnesses that are under great emotional stress tend to have a more detailed and accurate recall of crimes. In this study witnesses who had observed a bank robbery, either as a victim or a bystander, were interviewed and studied with respect to emotional reactions and memory for detailed information about the robbery. Overall, the results showed relatively high accuracy rates after an extended time with respect to specific details about the robbery (e.g. action, weapon, clothing). For some details, however, the witnesses showed a rather low performance (e.g. colour of eyes and hair, and details of the surrounding circumstances). Surprisingly, these findings contradict the negative relationship between stress and memory that many experts on eyewitness testimony believe in.
Reconstructive memory is the process by which we recall the past, assembling the past each time we remember (Matsumoto, 2009). When we try to remember the past, we do not reply an event as a video camera might. Rather, we “reconstruct” what happened, sometimes by drawing inferences about what happened or piecing together information that seems plausible. Bartlett’s theory of reconstructive memory is crucial to understanding the reliability of eyewitness testimony. Bartlett suggested that recall is subject to personal interpretation dependent on our learnt or cultural norms and values, and the way we make sense of our world (“Simple Psychology”, 2009). Frederick Bartlett was one of the first psychologists to propose Schematic theory. Schemas are a cognitive framework or concept that helps organize and interpret information. They allow us to take shortcuts in interpreting the vast amount of information that is available in our environment. Schemas can cause us to exclude pertinent information to instead focus only on things that confirm our pre-existing beliefs and ideas; therefore this...