Memory and testimony the psychology of the witness

3573
Charles McCarthy
Memory and testimony the psychology of the witness

Since the appearance and first development of psychology as a scientific discipline, some researchers were aware that the knowledge that was beginning to be generated in the field of human memory could be used to solve some unknowns and problems that arose in applied fields. One of these areas is that of the testimony that people make when they testify before the courts of justice or for the police.

Contents

  • Psychology in legal contexts
  • The effect of misleading information
  • Variables that affect the accuracy of the testimony
    • Variables related to the event
    • Variables related to the witness

Psychology in legal contexts

At the beginning of the century, authors such as Münsterberg, Binet or Stern published research papers on witness psychology and raised the need for judges, just as they are advised by different professionals on issues that fall outside their sphere of knowledge, have expert psychologists who advise them on different psychological aspects involved in legal contexts.

Nowadays, it is becoming a little more normalized that there are forensic psychologists, participation that is materialized in very diverse areas, such as the following:

  • Criminology.
  • Selection of juries.
  • The attribution of responsibility.
  • Police training.
  • The prison environment.
  • Attention to victims.
  • The expertise of psychological damage.
  • The witness's assessment.

When a person, at the police station or before a judge, explains the events they have witnessed or experienced, or when they are subjected to an identification round in which they must try to recognize a suspicious person, they are doing a memory exercise.

This memory exercise can be extraordinarily transcendent due to its consequences, however, it does not differ substantially from what we do when we try to relate to a friend the episode of a movie that we have seen or anything else, more or less trivial that has happened to us..

That our story of a film is not very faithful does not usually have much importance. However, errors in testimony can result in convicted criminals being acquitted or worse, innocent people being convicted. For this reason, judges, lawyers and prosecutors increasingly rely on psychological expertise to try to determine the degree of accuracy that should be attributed to a witness account, or an identification process.

The effect of misleading information

The effect of misleading information occurs when the person distorts the original memory of an episode due to the subsequent processing of information that is contradictory to what has actually been perceived.

When we perceive any event, the processes that operate in the different memory systems elaborate a representation of what we have perceived in our memory. However, if later, by any means, we receive information that does not agree with the original episode that we perceive, the probability that the representation of the original episode will be distorted in some way in such a way that, when we recall it later, we introduce inaccuracies or mistakes in our memory.

Psychologists interested in the issue of the accuracy of testimony have revealed the effect of misleading information from many experiments.

In an experiment by Loftus, Miller, and Burns (1978), for example, subjects were presented with a sequence of slides depicting a traffic accident. In this sequence of slides there was one in which the subjects saw a car stopped at a stop sign.

Given the sequence, the subjects were given a questionnaire of twenty questions about what they had seen. For half of the subjects one of these questions was: Did another car pass in the red car while stopped at the Stop sign? (Information consistent with what the subject had seen); For the other half of the subjects the critical question was: Did another car pass in the red car while stopped at the yield sign? (Information misleading or inconsistent with what the subjects had seen).

Subsequently, the participants performed a twenty-minute distracting task that consists of reading a text and answering some questions.

Finally, the subjects were subjected to a recognition test in which they were presented pairs of simultaneous slides from which the subjects had to select the one that had been previously presented in the sequence of the accident..

The critical pair of slides, in which the subjects had to choose the slide seen in the original sequence, featured the car stopped at the Stop sign, on one slide, and stopped at the yield sign, on the other..

The results showed that in the group of participants in which the question was consistent with the information seen, the percentage of subjects who chose the original slide was 75%, clearly above 50%, which would mark the effect of chance; while in the group that received misleading information in the question, the percentage of correct answers was 41%.

An experiment by Loftus and Palmer (1974) shows us how information after the event, subtly introduced according to the linguistic expression used, can alter people's testimony.

In this experiment, subjects were presented with a film showing two cars colliding with each other. Subsequently, the subjects were asked the following question:

How fast were the vehicles going when ... .?

For some of the participants, the verb used was they crashed; in the other group the verb was collided; in another dent, in another collide with, finally in another group of subjects the verb that was used was to contact.

We must bear in mind that the different verbs used in the question imply a gradation from more to less violence in the crash and, therefore, a higher speed prior to the crash..

The mean of the results in the estimation of the speed of the cars of the different groups according to the verb that was used was the following:

Verb used in the questionEstimated speed (km / h)
Crash40.8
Collide39.3
Dent38.1
Bump against34.0
Contact31.8

Although the variation in the speed estimate made by the subjects may seem small, think that there is enough to go from a legal speed to an illegal speed in a real situation..

The effect of misleading information, which has been demonstrated in many experiments, reveals interesting problems both applied and theoretical..

In the applied field, the problem arises of how to avoid that, when a person has witnessed or suffered as a victim a crime, the subsequent information that he receives distorts his memory in some way.

The information of an event can come from very different sources: the same police interrogations, conversations with other people, or even the information provided by the media..

In the theoretical field, the fundamental question is: what mental processes determine that the effect of misleading information occurs??

Several explanations are currently being investigated:

  • It may happen that misleading subsequent information erases and replaces part of the original representation of the event in the subject's memory..
  • It may happen that both the original information of the event and the subsequent misleading information coexist in the representation of the subject and several factors determine that the subject accesses one or the other.
  • It may happen that, although the subject retains in his representation the original information perceived in the event, several factors force him to give a biased response with information that is not represented in his memory.

Variables that affect the accuracy of the testimony

Witness psychology researchers have specifically addressed which factors or variables particularly affect the specific situation in which a person who has to testify finds himself and how these factors and variables make the witness tend to be more or less exact. Different classifications of the variables that affect the testimony have been elaborated and here we will review some of these variables, they have been the classification made by Ibabe (2000).

Variables related to the event

In the first place, we have the physical conditions such as the time that the perception of the event has lasted by the subject, the distance in which this perception has occurred and the degree of illumination there was. Obviously, the shorter the exposure time, the longer the distance, and the poorer lighting, the less likely the witness is to be accurate..

On the other hand, we have the characteristics of the event. For example, it has been shown that witnessing violent events is generally worse than witnessing events that do not involve violence. Furthermore, within an episode, not all the actions and objects involved have the same relevance and the witness tends to worsen when it affects less important elements..

Variables related to the witness

In the first place, we find a whole series of physical variables related to the witness. One of these is age. For example, it is known that the testimony of very young children, of preschool age, and that of the elderly tends to be worse than that of people who are between these age limits..

Another variable of a physical nature is the race of witness in relation to the race of the person on whom they must testify. We tend to code more elements and details, and consequently to better remember the physical appearance of people of our same race.

Differences in the quality of the control have also been demonstrated according to the sex of the control. Among others, women are known to remember violent events worse than men. Although the testimony of women is better.

Many cognitive variables related to the witness have also been investigated..

One of these refers to individual differences in memory skills for remembering events or remembering people. It has been shown that remembering events or identifying people are skills that do not have to match in one person. That is, we can be very skilled at remembering events and very little in identification processes or vice versa..

Another important variable for witness accuracy is attention. If it has been very focused on particular aspects of an episode (for example, the weapon that the offender was carrying), the memory of other aspects of the event will tend to be very poor. This is known as the weapon targeting effect..

A very important element in relation to the accuracy of the testimony is the degree of emotional activation that the event aroused in the witness. Although before we have said that both recounting an episode of a movie with a friend, and leaving testimony about a crime of which we have been victims or eyewitnesses are memory exercises, we cannot ignore that on many occasions the witness of a crime in a real case experienced the event with a high stress component.

The question is: will an episode that awakens a high degree of stress in those who perceive it be better or worse remembered than a neutral event? Today, unfortunately, we do not have a clear and simple answer in this regard..


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