Can The Human Memory Be Trusted?
Many factors can influence eye witness testimony (EWT), EWT is a term used in the legal system when witnesses recall information concerning individuals who have committed crimes. The factors that could affect the accuracy of EWT may include leading questions, age and anxiety. So can the human memory really be trusted with so many effecting factors?
Loftus and Palmer (1974) conducted a study with the aim of assessing the accuracy of memory after witnessing a car accident, and including leading questions to assess whether they could affect immediate recall. The researchers showed forty five students seven different traffic accidents, and giving each participant a questionnaire asking specific questions about the accidents. They also asked the critical question of ‘how fast were the cars going when they hit each other?’ however the other groups where given other verbs of smashed, collided, bumped and contacted instead of hit. Their findings included they word ‘smashed’ generated the highest mean score of 40.8 mph and ‘contacted’ generated the lowest of 31.8 mph. Loftus and Palmer reached the conclusion that the form of questioning has a significant effect on witnesses accounts of events. Therefore EWT is unreliable and inaccurate according to these researchers, although others can dispute this. Yuille and Cutshall (1986) interviewed thirteen people who had witnessed an armed robbery in Canada. These interviews took place four months later, and the interviews included two misleading questions, these questions did not affect the witnesses’ accuracy to accounts they had given police at the time of the crime, and very still detailed descriptions of the event. Meaning that information given after events does not affect memory and accurate recall in real life EWT.
Age can also affect accuracy, Parker and Carranza (1989) conducted a study to compare the accuracy between college students and primary school children. They had to identify a specific individual within a slide sequence of a mock crime. While identifying photos children found it easier to choose ‘someone’ compared to the adult witnesses however made more errors of identification compared to the adults. So errors can be made while identifying individuals at any age group, meaning it could be unreliable with this influence as well. However Yarmey (1993) asked 651 adults in public places to give a description of the physical characteristics of a young woman they had spoken to for fifteen seconds, two minutes ago. Young and middle age adults were more confident with their recalling, compared to older adults, although there were no significant differences in the accuracy of recall that could be because of the age group of witnesses.
Anxiety could also affect EWT. A really traumatic event (as some psychologists argue) could negatively impact the accuracy of eye witness testimony. Deffenbacher et al. (2004) conducted a meta-analysis of eighteen studies that were published between 1974 and 1997, aiming to discover the effects of high anxiety and accuracy of eye witness recall. His findings backed the theory that high levels of anxiety do negatively affect accurately. However, Christianson and Hubinette (1993) questioned 58 witnesses of real bank robberies, the witnesses that had been threatened in some way, had a more accurate recall to those that had not, and were not as emotionally aroused. The weapon focus effect could also decrease the accuracy of eye witness testimony as witness tend to focus more on central details (e.g. weapons) rather than peripheral details (e.g. offenders face and characteristics, or what else is going on). Loftus et al. (1987) conducted a study into the weapon focus effect, using two conditions, participants heard a discussion in another room and someone emerge with a greasy pen in their hand. The other group heard a heated discussion and someone emerge with a paperknife covered in blood. When asked to identify the man that emerged from fifty photographs, participants of condition 1 had a 44% accurate recall, compared to condition 2 which had a 33% accurate recall. Loftus believes the weapon from condition 2 distracted the participants, and could explain why EWT is not as accurate as it could be.
So, can human memory really be trusted? Arguments can be justified from both sides, with an extensive amount of evidence to back it. In the circumstances of a court case, it can be crucial for a prosecution to go ahead, however in this day and age much more accurate technology can be used to convict someone, for example DNA testing or Crime scene re-enactment. So EWT could be seen as dated in today’s legal system.