Violence and the Number of Perpetrators with Eye-Witness Memory - Essay Example

I. Human Memory: Perceptions and Reality There are several factors which have been known to affect the accuracy of human memory. The purpose of recalling is important, particularly in solving (violent) crimes, where eyewitness accounts are usually the strongest kinds of evidences. There are literature that suggest that if we have strong negative feelings about an event, we are most likely to remember it more accurately (Kensinger, 2007). The complexities and intricacies of the human mind have been a topic of interest for a long time. This is due to the fact that the reliability of data provided by participants in any study is usually dependent on the accuracy of their memory. In this essay, it will be argued that eye-witness memory is not reliable. This essay will firstly discuss the study by Krug & Weaver (2005) about eyewitness memory in civil cases which shows that memory performance is poor with a rating of only 20%, as with metamemory accuracy after a delay. The accuracy decreases when researchers deliberately delay the testing for more than a week. Then it will discuss the study done by Clifford and Hollin (1981) about witnesses’ memory performance after a violent incident, which shows that accuracy was low as well, and it decreased with the number of perpetrators seen, with the lowest accuracy recorded when the participants were shown a violent video with five perpetrators. II. Evidence The purpose of the study by Krug and Weaver (2005) was to conduct a study on the reliability of eye witness memory by studying memory in product identification, which is common in civil cases. The independent variables are the products used in the recipes and time, with eight levels (the number of products used) and two levels (a week and two weeks), respectively. The dependent variable is the memory performance after the subject has been exposed to the recipe and the said products. The participants were one hundred and ten Baylor University undergraduates who consist of ninety-six women and fourteen men. Their age range was 18 to 23 years old. These participants received extra credit for participating in the experiment. The procedure involved following a recipe and remembering the ingredients. They were tested separately, and were told that the researchers were investigating different kinds of writing instructions on the speed and accuracy of recipe mixing. They were also told that they would be timed and speed was important. Then, each participant randomly drew a number corresponding to the type of recipe they should use. But the kinds of recipes are all the same in reality, while the brands of the products used varied per recipe. The participants were then asked to come back a week after (Group A) or two weeks after (Group B). Then half of each group was given a 5-alternative forced choice recognition test, listing 5 brands for each of the eight products with product categories and brands within categories listed in alphabetical order. The other half of the groups did a free-recall test. The results state that product recognition occurred by chance with only 20% correct answers. The confidence of a person is not indicative of correct product recognition as well as metamemory accuracy. The participants also show bias in a sense that they reported using familiar brands even if there were no such brands used. The incidence of false product recognition increased during the course of time. The purpose of the study done by Clifford and Hollin (1981) was to determine the accuracy of eyewitness accounts and identification following the unprepared witnessing of either a violent or a nonviolent videotaped incident in which one, three, or five perpetrators participated was investigated. The independent variables are the incident (two levels: violent or non-violent) and the number of perpetrators (three levels: one, three or five). The dependent variable is the memory performance. The participants were sixty male and female undergraduate students of North East London Polytechnic. These participants were randomly selected. The procedure for the study involved showing the participants crime videos and letting them recall details about it. The participants were randomly seated in a dark room and were shown videotapes. After the viewing, the participants were asked to fill out questionnaires about the video and they identified the perpetrators, by picking a face in a pile of pictures. After identification, the participants were then asked to rate their confidence level as to their certainty of being correct. The results state that the memory performance and accuracy for both testimony and identification tests decreased as the violence increased. This is because violence causes stress to the witness, hereby altering one’s perception. It was also found that the accuracy of the memory decreased when the number of perpetrators increased. This supports the idea that eye witness memory is unreliable because most violent crimes occur in groups. As a conclusion, both studies suggest that eye-witness memory is not reliable when time, familiarity of a product, violence and number of perpetrators are variables in a scenario. Interpretation The study done by Krug and Weaver (2005) has many strengths. For instance, the study was done well in a lab so that it can simulate a real life situation wherein a product may be in need for product identification, as in civil cases for product liability. The results were highly reliable. The participants were randomly selected and they were treated identically except across independent variable levels. Therefore, there are no alternative causes of dependent variable. On the other hand, it has some limitations which are mainly regarding the participants’ sample. As they only represent one part of the society: the student population. In addition, their age range, which was 18 to 23, is very limited. They also consisted of a large number of females compared to the number of males. Thus, the participants do not represent the population well. Overall, the strengths of the study overweight the limitations. Therefore, the study is reliable enough to be an evidence for the thesis of this essay. These results are consistent with the other study as they show that human eye-witness memory is not reliable. Thus, this study supports the thesis of this essay about eye-witness memory being unreliable. The experiment of the second study was also done in a controlled environment, but more simulated in a sense that the participants were not given any instructions. The lack of instruction simulates real-life scenario where the person unexpectedly becomes a witness for a crime as preparation for crime can alter the memory performance of a person. The participants were picked randomly and they were treated identically except across the independent variable. Thus, there are no alternative reasons why the dependent variable could be altered, unless the participant has a problem that could affect his memory (stress, organic disease, etc). However, they only represent one sector of the population: the student population. It should be noted that other representatives could be used so that everyone in the society, especially in terms of age, can be tested of their memory and perception as these two elements can be crucial. Another limitation is that the videos showed were not in color. Accuracy could be improved if there were comparative processing of facts such as colors of the perpetrator’s clothing, hair and other striking details. Another thing is that the videos shown were not authentic; actors performed it. It would be more accurate if they had used real crime footage. The idea of increasing the number of perpetrators in a scene is actually a good variable because most violent crimes occur in groups as with the idea of not telling prior instructions to participants. With the result that the eye witness accounts in scenarios involving many perpetrators are not accurate, evidences in court cases should be reviewed. The results of the study are also consistent with the results of the other study which are not positive in terms of eye witness accounts. With these data, it is concluded that this study is congruent to the thesis of this essay that eye witness accounts are not reliable. These interpretations reflect the main thesis of the study regarding unreliable eye witness accounts. Many variables affect one’s memory performance and these facts are important to know as they are crucial in certain kinds of investigations, especially in cases where the alleged perpetrators are going to be jailed because of “accurate” eye-witness accounts. III. Conclusion This essay argues that eye-witness memory is not reliable. Upon reviewing two studies (Eyewitness Memory and Metamemory in Product Identification: Evidence for Familiarity Biases by Krug and Weaver (2005) and Effects of the Type of Incident and the Number of Perpetrators on Eyewitness Memory by Clifford and Hollin (1981), this statement proves to be true. There are several factors why eye-witness memory is not reliable. In the first study, it showed that time was a crucial factor in the ability to recall some of the products which were directly used in the experiment. Another factor that could affect one’s memory performance was the familiarity of the products used. In the second study, it showed that violence and the number of perpetrators are crucial in eye witness memory. The participants who engaged in violent scenarios have poorer recollections than those who had seen videos of crimes with non-violent incidents. It was also found that the more perpetrators are, the less the accuracy of the memory is. The findings of these studies are greatly helpful to courts and for the defendants who were incarcerated because of “eye witness” accounts. The studies prove how erroneous these accounts can be and should not be treated seriously enough to put someone in jail. References: Clifford, B. R., & Hollin, C. R. (1981). Effects of the type of incident and the number of perpetrators on eyewitness memory. Journal of Applied Psychology, 66(3), 364-364-370. doi:10.1037/0021-9010.66.3.364 Kensinger, E. A. (2007). Negative Emotion Enhances Memory Accuracy. Current Directions in Psychological Science, 16(4), 213-218. doi:10.1111/j.1467-8721.2007.00506.x Krug, K. S., & Weaver, C. A., I. (2005). Eyewitness memory and metamemory in product identification: Evidence for familiarity biases. The Journal of General Psychology, 132(4), 429-429-445. Retrieved from http://search.proquest.com/docview/213650932?accountid=14723 Read More