A new study showed that psychopaths have a larger streak area in their brain
Scientists using MRI scans have found that psychopaths have a 10% higher striatum, a group of neurons in the subcortical basal ganglia of the anterior brain, than ordinary people. This is a clear biological distinction between psychopaths and non-psychopaths.
Scientists at Nanyang University of Technology (NTU Singapore), the University of Pennsylvania and California State University have discovered a biological distinction between psychopaths and non-psychopaths. Using magnetic resonance imaging (MRI) scans, the scientists found that the striatum, an area of the anterior brain, was 10% larger in psychopaths than a control group of individuals with little or no psychopathic traits.
Psychopaths, or those with psychopathic qualities, are people who have a selfish and antisocial disposition. This is often characterized by a lack of guilt for their actions, a lack of empathy for others and, in some cases, criminal tendencies.
The striatum, which is part of the anterior brain, the subcortical region of the brain that encompasses the entire brain, coordinates many elements of cognition, including motor and action planning, decision-making, motivation, reinforcement, and reward perception.
Previous research has shown that psychopaths have hyperactive striae, but the influence of their size on behavior has not yet been confirmed. The new research demonstrates a significant biological difference between people with psychopathic tendencies and those who do not. Although not all people with psychopathic qualities break the law and not all criminals meet the criteria for psychopathy, there is a strong association. There is also significant evidence that psychopathy is associated with more aggressive behavior.
Understanding the role of biology in antisocial and criminal behavior can help improve existing theories of behavior, as well as inform policies and treatment options. To conduct their study, neuroscientists scanned the brains of 120 participants in the United States and interviewed them using Psychopathy Checklist-Revised, a psychological assessment tool to determine the presence of psychopathic traits in individuals.
Assistant Professor Olivia Choy of the NTU School of Social Sciences, a neurocriminologist who co-authored the study, said: “The results of our study help advance our knowledge of what underlies antisocial behavior, such as psychopathy. We find that, in addition to the social influences of the environment, 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. “
Professor Adrian Raine of the Department of Criminology, Psychiatry and Psychology at the University of Pennsylvania, who co-authored the study, said: these findings provide additional support for the developmental prospects of psychopathy - that the brains of these criminals do not develop normally during childhood and adolescence. ”
Professor Robert Schug of the School of Criminology, Criminal Justice and Emergency Management at California State University, Long Beach, who co-authored the study, added: “Using the Revised Psychopathy Checklist in a Community Sample it remains a new scientific approach: Helping us to understand the psychopathic traits of individuals who are not in prisons and prisons, but rather in those who walk among us every day. ”
Emphasizing the significance of the work of the joint research team, Associate Professor Andrea Glenn of the Department of Psychology at the University of Alabama, who is not involved in research, said, “By replicating and expanding previous work, this study builds our confidence. that psychopathy is associated with structural differences in the striatum, a region of the brain that is important in a variety of important processes for cognitive and social functioning. Future studies will be needed to understand the factors that may contribute to these structural differences. “
The results of the study were recently published in the peer-reviewed academic publication Journal of Psychiatric Research.
Higher striatum, greater appetite for stimulation
Through analyzes of MRI scans and the results of interviews to detect psychopathy, the researchers linked a higher striatum to an increased need for stimulation, through strong sensations and enthusiasm and a higher likelihood of impulsive behaviors.
The striatum is part of the basal ganglia, which is made up of groups of neurons deep in the center of the brain. The basal ganglia receive signals from the cerebral cortex, which control the knowledge, social behavior, and discernment of sensory information that deserves attention.
In the last two decades, however, the understanding of striatum has expanded, indicating that the region is linked to difficulties in social behavior. Previous studies have not addressed whether striatal enlargement is observed in adult females with psychopathic traits.
Neuroscientists say that in their study of 120 individuals, they examined 12 females and found, for the first time, that psychopathy was linked to increased streak in women as well as men. In human development, the striatum usually becomes smaller as the child matures, suggesting that psychopathy may be related to differences in how the brain develops.
Asst Prof Choy suggested: “A better understanding of the development of the striatum is still needed. Many factors are probably involved in why an individual is more likely to have psychopathic traits than another individual. Psychopathy may be related to a structural abnormality of the brain that may be developing. At the same time, it is important to recognize that the environment can also affect the structure of the striatum. “
Prof Raine added: “I have always known that psychopaths go to great lengths to seek rewards, including criminal activities involving property, sex and drugs. We now find a neurobiological basis for this impulsive and stimulating behavior in the form of enlarged striatum, a key area of the brain involved in rewards.
Scientists hope to conduct additional research to find out the causes of striatal enlargement in individuals with psychopathic traits.
Reference: “Higher striated volume is associated with increased adult psychopathy” by Olivia Choy, Adrian Raine and Robert Schug, March 6, 2022, Journal of Psychiatric Research.
DOI: 10.1016 / j.jpsychires.2022.03.006