Criminal Psychology: History, What It Studies, Techniques, Authors

The  criminal or criminological psychology  is the branch of psychology that is responsible for studying the thoughts, intentions, actions, reactions and beliefs of criminals. In addition, it also studies criminal behavior in general to understand what leads a person to commit it and the consequences of these actions.

Although the two disciplines are often confused, criminal and forensic psychology are actually quite different currents. While a forensic psychologist can work in any field related to justice and legality, criminologists only dedicate themselves to investigating the people who commit crimes and what surrounds their actions.

On the other hand, criminal psychology is closely related to criminal anthropology. Both disciplines try to understand what factors can lead a person to commit a crime; but they also try to better understand what happens after it, such as during the flight from the law or in the judicial process.

Criminological psychology has gone in a few years from being a relatively unknown branch of the study of mental health to one of the most demanded by both students of this discipline and in the professional field.

History of criminal psychology

Early years

In the first decades of the 20th century, psychologists became interested in the underlying causes of criminal behavior and began to wonder what were the reasons that could lead a person to commit a crime. Because of this, criminal psychology initially started out as highly experimental in nature.

The first psychologists to study topics such as crime or the personality of criminals relied mainly on field studies. For example, at first they used tools such as personality or intelligence tests to try to find variations between the normal population and the one that committed crimes.

Some of the early criminal psychologists developed the theory that most criminals had lower levels of intelligence than the general population. For these early researchers, criminals would be less able to adapt to society due to their lower intellectual and moral capacities, and therefore they would function in their environment using less acceptable methods.

One of the main defenders of this current was Hans Eysenck, creator of one of the most famous theories of personality in the entire history of psychology. Influenced largely by Darwin’s theory of evolution, he believed that people who commit crimes did so driven by innate biological factors beyond their control.

Second half of the 20th century

Starting in the 1960s, more and more authors began to emerge interested in understanding the motives that lead a person to commit a crime. Most of them continued to focus on biology and the innate predisposition to crime, although the first voices that focused on the environment in which the person moved also began to appear.

Thus, many of the early theories in the field of criminal psychology focused on aspects such as aggressive personality, extraversion, search for sensations or psychopathy. However, in the second half of the 20th century, researchers focused more on understanding how people’s development affected their criminal tendencies, and how this interacted with their innate traits.

Finally, some criminal psychologists began to wonder how the person’s socioeconomic background affected their criminal tendencies; and they realized that factors such as economic level, social class, personal relationships or family situation had a great influence on the probability that they would carry out a crime or not.

From this moment the discipline was developing little by little; and in the last decades of the 20th century it came to be considered an independent branch of the rest of psychology. Currently, criminal psychologists collaborate in many cases with all members of the judicial system, to help them better understand what happens in the minds of criminals and to be able to foresee their actions.

What does criminal psychology study?

Since its inception, the main objective of criminal psychology has been to understand what leads a person to commit a crime as thoroughly as possible. In this way, professionals in this discipline try to foresee the appearance of crimes and design interventions to rehabilitate people who have previously committed them.

Collaboration with justice

In addition, criminal psychologists also collaborate on many occasions with the justice system to help police officers and investigators to catch those responsible for a specific crime. By studying the evidence and crime scenes, these professionals can get a very detailed idea about the characteristics of the criminal that can help them predict his movements and find him.

To achieve this, criminal psychology is based both on exclusive investigations of this discipline and on data from other branches. Thus, for example, much of the data used today in criminology originally arose from the study of personality and individual differences.

Techniques and Instruments

Creation of the criminal profile

One of the most common tasks for criminal psychologists is to perform the mental profile of a criminal. This technique tries to understand the psychological state of the person and analyze their thoughts, their personality and their way of acting.

For this, the psychologist tries to identify traits of the criminal such as age, gender, environment of origin, physical characteristics or socioeconomic status. All of this is studied before the offender is caught, usually by examining the evidence and the crime scene.

From the data extracted from this study, the techniques of criminal psychology make it possible to identify the most probable mental state of the offender. Nowadays the methods used to make criminal profiles are very sophisticated, and allow to collect a large amount of information even in the most complicated cases.

Criminal Study

On the other hand, criminal psychologists can also engage in other tasks such as studying criminals who have already been caught. For this they can use tools such as:

  • Tests
  • Interviews
  • Research on your environment
  • Other techniques adapted from different currents of psychology.

Knowledge of the laws

Finally, since criminal psychology tends to collaborate closely with other fields of justice, professionals in this area must fully understand the laws that apply in their territory and the most common procedures when dealing with criminals.

Scope of application

Criminal psychology can be applied in a multitude of different fields. However, in most cases the professionals in this discipline end up developing their work in one of four areas: clinical, experimental, actuarial, and consulting. Next we will see what each one of them consists of.

– Clinic

Criminal psychologists specialized in this area often work with criminals who have already been caught. Its work consists of studying the psychological state of the person, as well as the existence of possible mental illnesses that make it necessary to follow a different legal procedure than usual.

To achieve the most reliable result possible, the clinical criminal psychologist uses tools such as tests, interviews and live tests that allow him to know in depth the mental state of the offender.

– Actuarial

This specialty of criminal psychology is mainly responsible for studying the probabilities that a certain event has actually occurred, and trying to predict the next movements of a criminal. For this, the main tool of these professionals is statistics.

– Experimental

Experimental criminal psychologists conduct tests and investigations that allow them to determine whether the allegations that have been made against a person may or may not be true.

For example, an expert in this area may test the hearing of a witness to determine whether they really would have been able to hear something that they have stated in their statement.

– Consulting

The last area that criminal psychology professionals can pursue is consulting. When law enforcement officials and legal teams are in doubt about how to proceed with a specific case, they can enlist the help of a law enforcement professional for advice and help in bringing it to fruition.

In this sense, criminal psychologists can advise on issues such as the best way to carry out an interrogation, the best interpretation of the available leads or the possible ways to continue with the investigation.

Featured Authors in Criminal Psychology

There is no single unified theory within criminal psychology. However, some authors have developed research and proposed theories that have greatly helped to advance this discipline. Some of the most important are the following:

– Hans Eysenck was the first to investigate the personality traits of criminals.

– Albert J. Reiss created the theory of social control, one of the most accepted in this field.

– Eric Goffman developed the theory of labeling, essential to understand why criminals are more likely to re-offend than a normal person.


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