The brain of psychopaths has a very particular characteristic

Psychopathy is the result of a complex combination of factors, both environmental and genetic. Now, we have discovered a new brain peculiarity. We explain it to you.

The brain of psychopaths has a very particular characteristic

Last update: 04 July, 2022

A recent research work has shown that psychopaths have a larger brain region than normal. It is, specifically, the corpus striatum: a set of subcortical structures that are in turn part of the basal ganglia. It is an area related to important processes that not only have to do with our cognition.

It should be noted, however, that this is not the first neurological peculiarity that has been discovered in terms of psychopathic behavior. We have spent years uncovering layer by layer the mystery of what is known as the “dark personality”. We know, for example, that in certain processes, such as empathy, feelings of guilt, fear or anxiety, they present serious alterations.

However, it is relevant to qualify an essential aspect. Genetic and neurological alterations are not enough to explain why a man or woman is a psychopath. It is enough to remember a name: that of the doctor James Fallon. He is one of the most prestigious neurologists in the world. He himself discovered that he has the genes and neurological characteristics of this profile.

Moreover, in his paternal family there were up to seven murderers, one of them being the famous Lizzie Borden. However, Dr. Fallon was able to enjoy a structured and happy childhood. What we know is that the environment is, in many cases, that factor that activates or deactivates the psychopathy gene, the one that many people carry within them.

Alterations in socio-emotional circuitry are a feature in offenders with a psychopathic personality.

Psychopathic people show a larger striatal region

Psychopaths have a larger than average brain region

Neuroscientists at Nanyang Technological University in Singapore (NTU Singapore), the University of Pennsylvania, and California State University very recently published a study very interesting. Now, we know that psychopaths have a larger brain region than average: it is the striatum.

This factor would allow us to make a distinction between those who could present this trait and those who could not. It would be enough to perform an MRI to find out. Specifically, what we would see is that people with psychopathic traits (active or latent), present a striated region that it is 10% larger than that of those who lack this feature.

Now, the question that comes next is more than obvious. What particularities are there in who presents this nuance in their brain? We analyze it.

An overactive striatum: the mind in search of rewards

The striatum deals with different functions that are essential for the human being. Among them are those related to motor learning, movement or procedural memory. However, also it is decisive in tasks such as motivated behavior or the ability to select actions based on expected rewards.

Good, If there is one aspect that defines psychopaths, it is their instrumental behavior. That is, they act only for their own interest and to obtain what they want. The striatum controls, through dopamine secretion, the brain’s reward system. What has been evidenced in this study is that this function presents a high activity in said profile.

In other words, let’s think about what it means to have a person with low empathy, but highly motivated to achieve what they want (whether legal or not). The most likely result would be a pattern of behavior that violates ethical, moral and legal principles..

Behavior more prone to violence

Psychopaths have a larger than normal brain region: the striatum. However, they also present very striking structural and functional changes in the brain. Jobs such as those carried out at the University of Turku, in Finland, show great impulsiveness, lack of cognitive control and a very inefficient regulation of emotions at the social level.

All this increases the probability that they will become involved in violent and criminal actions. It should be noted, however, that not all people with psychopathic traits cross this threshold. Many become those aggressive coworkers, those bosses who abuse their authority and lead to disaster in their own company.

It is important to point out that only 1% of the population demonstrates a high-grade psychopathy capable of leading them to aggressive and illegal acts. People with low-grade psychopathic traits abound to a greater degree, with whom it is difficult to live, those who deceive and manipulate to achieve what they want. Reprehensible conduct, unethical but not reportable at the legal level.

The vast majority of psychopaths are not in a prison, but rather share social spaces with us. They can be our bosses, teachers, co-workers and even our partners.


Professor Adrian Raine, from the department of criminology, psychiatry and psychology at the University of Pennsylvania is a co-author of the study we have referred to. In it he points out that heredity has a lot to do with what psychopaths have a larger brain region than normal. That is, it can be inherited from parents to children.

Does this mean that having a larger striatum would determine our psychopathic behavior? The answer is no. Presenting certain brain abnormalities associated with psychopathy does not activate this trait in 100% of cases. It is a risk, obviously. However, as we indicated at the beginning, there are more associated variables apart from genetic or biological ones.

Growing up in a safe, emotionally nurturing social and family environment, free from traumatic experiences, can numb the development of this characteristic. Although we still do not know everything about this personality disorder, it is no less true that we learn a little more about it every day.

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The brain of psychopaths has a very particular characteristic