By Witness memory is not always accurate. What makes people distort their testimony when they witness a crime? Are men or women more reliable?
If you have ever witnessed a crime or if you have some knowledge of forensic psychology, you will know that the memory of that event can be biased or distorted by different variables (our memory, in this case as in others, is not a mere stenographer of reality). This and other issues have been addressed by the psychology of testimony through the identification and prevention of the factors that influence the memory of witnesses.
In this article, learn what the psychology of testimony is and what elements make people who witness a crime (whether it be a robbery, a murder, a rape, etc.) give a somewhat distorted account of the events. Now, are children or adults more reliable? Men or women? We answer these and other interesting questions about this discipline of forensic psychology.
Psychology of testimony and witness memory
The term “ psychology of testimony ” first appeared in 1908, by Hugo Münsterberg; he argued that “advice from psychologists was indispensable so that judges, who had to operate in a field foreign to their own, that of human perception and memory, could form a more precise idea of the accuracy of testimony .” Today, the psychology of testimony deals with the conditions that delimit the accuracy of witness statements and the factors that affect the credibility of witnesses and their testimonies.
Thus, the psychology of testimony is a branch of psychology that deals with analyzing the quality of witness memory in the forensic field. By “ witness memory ” we mean the set of knowledge and research that, based on studies on human memory, evaluates the quality of the testimonies given by essential witnesses about crimes and accidents.
Typically, when witnesses of a crime witness such a scene they make two mistakes:
- Errors of omission : when they forget details of what happened.
- Errors of commission : when they unintentionally add new data and information that is not real to fill in the gaps they know they have.
But what factors distort the testimony of a person who has witnessed a crime? Let’s talk about the most important ones.
What factors influence our memory when we witness a crime?
The psychology of testimony has studied the distortions in the testimonies of people who witness a crime. Following G. Wells (1978), we can differentiate some factors that influence such testimony, such as:
1. Circumstances of the facts
We are talking about those variables that we know or intuit most frequently affect the reliability of testimonies, but of which we can only hypothesize their influence. In principle, no one chooses or can control these variables , since they are determined by the chance of events. They are divided into:
Factors of the situation
The witness’s memory is influenced by:
- The environmental conditions in which the incident occurred (for example: distance, darkness, fog).
- The type of event involved (an accident, a rape, a robbery, etc.).
- The time available to the witness to observe the event.
- The activity that the witnesses have been engaged in up to the time of the statement (comments among themselves, the effect of conformity to the majority opinion, etc.).
Witness factors
In this case, we are talking about the characteristics of each witness, such as age or sex, which can be assumed to have an effect on the accuracy of the testimonies.
2. Variables specific to the system
The system chosen to take witness statements also has an impact on the witness’ memory . We are referring here to the variables that the police or magistrates and lawyers can manipulate to optimize the narration of the facts or the identification of a suspect.
That is, the instructions given to witnesses, the time interval between the complaint and the statement, the order in which the questions are asked (and the type of questions), the composition of the identification parades, etc.
Phenomena that distort the witness’ memory
Regarding the circumstances of the event, we find some interesting phenomena that influence the witness’s memory, such as:
The effect of arousal and violence
Most studies, such as that of Zanni and Oferman (1974), agree in pointing out that high levels of arousal negatively affect the accuracy of witnesses’ memory .
The violence of the incident plays a key role in all of this, as it can increase arousal levels ; thus, according to studies such as that of Clifford and Hollin (1978), the witness’s memory is less precise or accurate under violent conditions than under non-violent conditions.
The role of sex in witness memory
According to Clifford and Hollin (1978), men remember more violent details than women , while in the case of a non-violent incident the opposite occurs. And when instead of narrating the events, the suspect is identified, women are more reliable than men.
Research by Yarmey (1979) suggests that women recognize a face more accurately , and that they are especially good when the faces are of women.
Furthermore, statements about clothing, actions and physical appearance, both of men and women, are more reliable in the case of women. According to Mc Gehee (1937), men recognize voices better than women (84% vs. 59%).
The age
If we focus on the memory of the facial characteristics of criminals, children are worse witnesses than adolescents and adults. However, there is no difference with adults when it comes to witnessing an event. It is estimated that the accuracy with which people identify a person remains stable from approximately 17 years of age.
On the other hand, children are easily influenced by the people who question them, which is not so easy for adults. Furthermore, children find the lineup system much more stressful than identification by means of photographs , and stress may worsen the accuracy of their memory, according to Dent (1978).
Other influencing factors
We also found other factors influencing the witness’ memory, such as:
- Stereotypes.
- The limitations of memory itself.
- The person’s profession (police officers, for example, are more accurate at remembering details, but only for a short period of time after the events).
Witness memory: not as reliable as one might think
As we have seen, the memory of a witness is not as reliable as it seems. Our memory, although extremely powerful, is not a perfect ability nor a photograph of reality, but rather a reconstruction of it. And in high-stress situations, such as a criminal event, this cognitive ability can fail.
Most of these memory lapses are completely involuntary and, as we have seen, depend on personal factors of the witness, but also on external factors (the type of event, the time of observation, the conditions of the interrogation, etc.).