Factors that affect the accuracy of eyewitness testimonies

Eyewitness testimony is the normally verbal recount of an person who has experienced an event, typically of a offense. Eyewitness testimony relies to a great extent on the capableness of the person ‘s to accurately tell the event. In a test, the jury is most frequently persuaded due to the statement ( s ) of the informants. Besides, in instances where small material grounds can be collected, eyewitnesses are the focal base for making a finding of fact. It has been argued that because testimonies are mostly based on fallible memory which can be influenced by a assortment of factors, it should non be depended upon. The contention of this essay is to place and measure the extent of truth of this claim by placing and measuring factors that affect memory and by reexamining experiments and instance surveies to make a decision on this affair. Memory and therefore eye-witness dependability has become an issue of importance due to the high per centum of mistakes in identifying and prosecuting accused persons. Therefore, the dependability of eyewitness testimonies and impact on tests should be reviewed.

Memory is defined as a “ sort of depository in which facts ( information ) may be retained over some period of clip ” ( Loftus, 1979 ) . Harmonizing to the Atkinson and Shiffrin theoretical account of memory storage ( 1971 ) , memory is made up of three different types of information shops, each with different continuance, capacity and map. The first is Centripetal Memory. This type of shop stopping points for the spilt second when persons collect information from their centripetal systems and preserves information in its original centripetal signifier. The sense variety meats are limited in their ability to hive away information about the universe in an unrefined manner for more than a 2nd. Therefore, information is filtered through or selected by attending for farther memory processing into the following type of memory shop. This procedure of sing and filtrating information is called acquisition. The following memory shop is Short-run memory allows persons to retain information long plenty to be used and lasts about between 15 to 30 seconds. Miller ( 1956 ) proposed that Short-term Memory had a capacity of about 7 balls of information. If certain actions are carried out, the information will be transferred to the last type of memory shop, Long-run Memory. Long-run Memory provides keeping of information which can last between proceedingss to a life-time and has a illimitable capacity. The procedure of information deposited in the short-run and long-run memory shop is called keeping. Information is invariably being transferred between these shops. When informants are asked to give recount of what they witnessed, information is taken from the long-run memory shop and this procedure is called acquisition.

Events during these three procedures may impact the quality of the eyewitness testimony. Information may non hold been perceived in the first topographic point during the acquisition procedure, information may be forgotten or interfered during the keeping procedure or information may be unaccessible during oppugning at during the retrieval procedure.

Events during the Three Procedures

During the acquisition procedure, there are a figure of factors that can impact an eyewitness ‘ study of an event. This can be divided into event factors and witness factors. This subdivision of the essay will measure the consequence of these factors on the dependability of eyewitness testimony.

Exposure clip to the event or object of focal point is an event factor. Laughery et Al ( 1971 ) tested topics on their callback based on the exposure clip to a image, showed one at a clip of different places of a human face. Two Caucasic male mark faces were used, one with fair-colored hair and skin color with spectacless and another with a darker-colored hair and skin color without spectacless. The independent variable is the clip the topics viewed the images, which ranged from 10 seconds to 32 seconds. The topics were them asked, about eight proceedingss after exposure to place the mark within a series of 150 slides of human faces. The dependent variable is the truth of the topics ‘ callback. Fifty-eight of the topics who viewed the images for 32 seconds right identified the mark but merely 47 per centum of the topics who viewed the images for 10 seconds right identified the mark. This shows that the more clip a informant has to see the mark, the more accurate their callback will be. This research is important as it is really scientific and exactly tested a specific variable that affects memory and callback. Although this is so, it was besides conducted in an unreal environment and therefore, has low ecological cogency. The research may besides incorporate cultural and gender prejudice as it merely tested for Caucasic males as the mark. Therefore, it application to marks of different civilizations or gender is questionable.

Estimating factors such as clip, velocity or distance is frequently asked of eyewitnesses. This involves comprehending the event and accurately deducing information from it. Marshall ( 1966 ) ‘s experiment tested topics ‘ appraisal of clip. Four hundred and 91 topics watched a 42 2nd movie and a hebdomad after they had given their written and unwritten studies of the event, they were questioned as to the continuance of the event. On norm, topics gave an estimation of about 90 seconds. The consequences show that informants can inaccurately gauge certain factors of an event. Although the consequences are important, the survey was conducted in a controlled environment which gives it small ecological cogency. To farther measure the truth of this survey, an extra survey that can be considered is Buckhout et al. ( 1975 and 1977 ) ‘s survey on the effects if eyewitness testimony in a existent state of affairs by presenting an onslaught where a pupil attacked a professor in forepart of 141 informants. The onslaught lasted for 34 seconds but when interviewed subsequently on, the mean estimation of the continuance of the event was 81 seconds, about twice the existent clip. This survey supports ‘ Marshall ‘s survey which shows that there is a inclination for informants to overrate the continuance in an event. This is important in most instances, particularly for instances of self-defence where the clip between the onslaught and the revenge is really important in the classification of the action.

Another event factor is the force of the event. A research done by Clifford and Scott ( 1978 ) investigated the ability of eyewitnesses to comprehend violent and non-violent events. Forty-eight topics with equal figure of work forces and adult females watched either one of two tapes. In the non-violent version, the characters were involved in a verbal exchange and weak restraining motions. In the violent version, one of the characters physically assaults another character. In an attempt to be even, the start and terminal of the tapes were manipulated to be indistinguishable. It was found that regardless of gender, the degree of callback is significantly lower for those who viewed the more violent tape. It is inferred that this is due to the greater sum of emphasis that is produced in response to the violent event. This shows that eyewitness testimony of a violent event should be considered with the possibility of a higher rate of inaccuracy. Though the consequences are important due to the high dependability of the scientific method used, it besides lacks ecological cogency as it was conducted in an unreal environment where informants do non really see the event.

An event factor that is linked to the informant factor, emphasis, is weapon focal point. Easterbrook ( 1959 ) found that under high emphasis, persons tend to concentrate more on a few characteristics of their environment and less attending to other characteristics. Weapon focal point is where a offense victim is faced with an attacker who is flourishing a arm.

During an event, emphasis is a witness factor that should be taken into history. This refers to the degree of emphasis or fright that a informant experiences that may act upon their perceptual experience during the acquisition procedure of the event. A fake instance survey done by Berkun ( 1962 ) placed army recruits in a nerve-racking state of affairs. They were isolated with the exclusion of a telephone nexus. Then, they were told that they were in danger to bring on anxiousness and were required to mend a broken wireless by following a series of complicated instructions. It was found that the high degree of anxiousness impaired public presentation of the topics. As this instance survey was conducted during a period of different ethical criterions than today, there are ethical deductions to be considered. However, the consequences of this instance study significantly supports the Yerkes-Dodson jurisprudence ( 1908 ) which states that emotional rousing facilitates larning and public presentation up to a point after which there is a decrease. This can be applied to eyewitnesses who experience emphasis. Their senses may be stimulated but after a point, their acquisition procedure will be negatively affected. Although this is so, this instance survey has merely looked at male soldiers, therefore when applied to the general population, it lacks ecological cogency.

Eye-witnesses are being tested on their keeping of information from their Long-run Memory. Because retained information and therefore, memory is being transferred between memory shops, it is possible that it can be influenced, enhanced or even distorted. Numerous researches have been carried out to look into the truth of this or the extent of influence that may happen.

Loftus and Palmer ( 1974 ) carried out an experiment to look into the consequence of taking inquiries on the truth of participants in remembering a auto clang. 45 participants were separated into 7 groups and each group watched a picture of traffic accidents. The picture lasted from 5 to 30 seconds. After watching the picture, participants had to give an history of what they had merely seen. The independent variable is the inquiry “ About how fast were the autos traveling when they hit each other? ” . The word ‘hit ‘ is replaced with the words ‘smashed ‘ , ‘contacted ‘ , ‘bumped ‘ and ‘collided ‘ for different groups. The participants answer as to the estimation of the autos ‘ velocity is the dependent variable. Loftus and Palmer found that the average estimation of velocity for more aggressive words such as ‘smashed ‘ is higher than less aggressive words such as ‘contacted ‘ . The consequences are extremely important, p & lt ; 0.005 harmonizing to analysis by discrepancy of the information. This indicates that there is an influence of the diction used on the velocity estimates. This experiment supports the thought that eye-witness testimony can so be flawed or manipulated by recounts under oppugning such as an history of an incident from an eye-witness by a police officer. However, unfavorable judgment of this experiment is directed at its ecological cogency. As the experiment was conducted in a controlled research lab environment and the auto clang was merely viewed, non experienced, the application of the consequences of the experiment is questionable when applied to real-life state of affairss.

Contending the consequences of this experiment is Yuille and Cutshall ( 1986 ) instance survey of a existent life event. 13 participants were interviewed utilizing Loftus and Palmer ‘s ( 1974 ) technique in their callback four to five months after witnessing an attempted robbery in daytime where one person was killed and another, earnestly wounded. It was found that there was a really high degree of similarity between the histories given by the informants, the histories did non change in response to prima inquiries and that the informants were able to remember the event in item. Additionally, histories of those who were more hard-pressed had a higher truth degree. These consequences are different to Loftus and Palmer ( 1974 ) . The oculus informants did non change their histories greatly in response to prima inquiries. As this is a instance survey, it holds high ecological cogency unlike research lab experiments. Although this may be true, Yuille and Cutshall ‘s instance survey was of an event that was comparatively traumatic event and was viewed in ideal conditions. Most incidents do non mirror this scene. Besides, it was an probe of merely one instance survey. Hence, the application of these findings is problematic when applied to general oculus informant testimonies.

Loftus and Zanni ( 1974 ) conducted a alteration of the original Loftus and Palmer research to look into the consequence of station event information on memory.

Specifying memory

Theories/Models of Memory

Consolidation Theory

Ecological Cogency

Forms of Eyewitness Testimony

There are multiple ways in which eyewitness testimonies can be given. This essay aims to measure chiefly, exposure spreads, recounts under oppugning, line-ups and photo-based line-ups and. Each signifier has its ain advantages or disadvantages in the rating of its facilitation or hinderance to the truth of testimonies.

Line-ups + Photo based line-ups

Witness expected to take one

Choosing of suspect by old exposure ( s ) shown

Line-up size

Features of line-up persons

Photo spreads

Merely based on facial visual aspect

Biasness of exposure quality

Multiple-recognition trial

Recounts under oppugning

Type of fact

Investigator ‘s influence

Memory

Acquisition: –

Age

Gender

Weapon focal point + Violence of event

Stress

Exposure clip

Retention: –

Interaction with other informant ( Es )

Media coverage of event

Time interval

Retrieval: –

Method of oppugning

Question diction

Assurance

Loftus 2002: Washington snipper – & gt ; white new wave.

Frederic Vartlett: memory 1932