THE ESSENTIAL
- Psychopaths or people with psychopathic traits are defined as patients with an egocentric and antisocial personality.
- The striatum coordinates multiple aspects of cognition, such as decision making, motivation, reward perception, motor and action planning.
- During human development, the striatum typically becomes smaller as the child grows, suggesting that psychopathy may be linked to differences in brain development.
Recently, neuroscientists from the universities of Nanyang in Singapore, Pennsylvania and the State of California in the United States revealed the existence of a biological difference between people who are psychopaths and those who do not suffer from this disorder. To reach this discovery, the researchers carried out a study published in the journal Journal of Psychiatric Research. “Previous research has reported increased striatum volume in adults with psychopathy, but has not conclusively determined the impact of its size on behaviors”they said.
As part of this work, Singaporean and American scientists hypothesized that the size of the striatum, i.e. an inner part of the brain that regulates impulses in particular, is greater in people with psychopathic traits, and that this size association is caused by the need for stimulation and impulsivity.
In psychopaths, the striatum is 10% larger
For the purposes of their study, the team measured the volume of the striatum of 108 men using magnetic resonance imaging (MRI). The researchers also questioned the participants using the Psychopathy Checklist – Revised, which is a psychological assessment tool to determine the presence of psychopathic traits in patients. “Subsidiary and exploratory analyzes were conducted on a small sample of women”can we read in the works.
According to the results, the striatum was on average 10% larger in psychopaths than in participants with little or no psychopathic traits. The authors linked a larger striatum to an increased need for stimulation, through thrills and excitement, and a higher likelihood of impulsive behaviors. According to research, psychopathy in women was also associated with an increase in the volume of the striatum.
Their brain “does not develop normally during childhood and adolescence”
“We find that in addition to environmental and social influences, it is important to consider that there may be biological differences, in this case the size of brain structures, between antisocial and non-antisocial adults,” said Olivia Choy, author of the study, in a statement. “Biological traits, such as striatum size, can be passed down from parents to their child. These findings provide further support for neurodevelopmental perspectives of psychopathy, namely that the brains of psychopaths do not develop normally during life. childhood and adolescence, added Adrian Raine, author of the works.
According to neuroscientists, a better understanding of the development of the striatum is needed. “Many factors are likely involved in why one individual is more likely to exhibit psychopathic traits than another. Psychopathy may be related to a structural abnormality of the brain which 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”, explained Olivia Choy.