Psychopaths are self-centered individuals, who lack empathy (they are unable to put themselves in another’s place, or feel sorry for the pain of others), and have no guilt or remorse for their bad actions. We have seen them get along with ease as the protagonist of a psychological thriller or as a serial killer, but most are well integrated into society and do not usually commit crimes, except if they satisfy certain instincts or achieve their goals (money, power, live). of their victims…). But many wonder what differentiates a psychopath from someone ‘normal’.
Psychopathy is not exactly a mental illness, but rather a fairly widespread personality disorder, and although its causes are not exactly known, a team of neuroscientists from Singapore’s Nanyang Technological University (NTU Singapore), the University of Pennsylvania and California State University, has found a biological difference between psychopaths and non-psychopaths.
Using magnetic resonance imaging (MRI) they found that a region of the forebrain known as the striatum was on average 10% larger in psychopathic individuals compared to another group of control individuals who had low or moderate psychopathic traits. null.
The striatum is located in the forebrain and is responsible for coordinating numerous aspects of cognition, including motor and action planning, decision making, motivation, reinforcement, and the perception of rewards. The new study, which has been published in the Journal of Psychiatric Research, shows that there is a significant biological difference between people with psychopathic traits and those without.
Psychopaths’ brains don’t develop normally
Not all psychopaths break the law, nor do all criminals meet the criteria to be diagnosed with psychopathy, but there is a bidirectional relationship and there is evidence that psychopathy is associated with more violent behavior. Understanding the role biology plays in antisocial and criminal behavior can help find treatment options.
“In addition to social environmental influences, there may be differences in biology, such as the size of brain structures, between antisocial and non-antisocial individuals.”
The researchers scanned the brains of 120 people in the United States, who they also interviewed using the Psychopathy Checklist-Revised, a psychological assessment tool that determines the presence of psychopathic traits in people. The results linked having a larger striatum with a greater need for stimulation through emotions and a greater likelihood of impulsive behaviors.
Assistant Professor Olivia Choy, from the NTU School of Social Sciences, a neurocriminologist and co-author of the study, said: “The results of our study help advance our understanding of what underlies antisocial behavior such as psychopathy. We found that in addition to social environmental influences, it is important to consider that there may be differences in biology, in this case the size of brain structures, between antisocial and non-antisocial individuals.”
“Because biological traits, such as striatum size, can be inherited from parents to children, these findings lend additional support to the neurodevelopmental view of psychopathy: that the brains of these criminals do not develop usually during childhood and adolescence,” says Professor Adrian Raine, from the Departments of Criminology, Psychiatry and Psychology at the University of Pennsylvania, co-author of the study.
In the study, the researchers examined 12 women and observed, for the first time, that psychopathy is also linked to an enlarged striatum in women. Because the striatum typically becomes smaller as a child matures, this finding suggests that psychopathy may be related to differences in the way the brain develops.
Choy adds: “A better understanding of the development of the striatum is still needed. Many factors are likely to be involved in why one individual is more likely to have psychopathic traits than another individual. Psychopathy may be related to a structural abnormality in the brain that may be developmental in nature. At the same time, it is important to recognize that the environment can also have effects on the structure of the striatum.”
Professor Raine concludes: “We have always known that psychopaths go to great lengths to seek rewards, including criminal activities involving property, sex and drugs. We are now discovering a neurobiological underpinning for this impulsive and stimulating behavior in the form of enlargement of the striatum, a key area of the brain involved in rewards.”
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