The research found that the striatum region of the brain was on average ten percent larger in psychopathic individuals compared to a control group of individuals that had low or no psychopathic traits.
A new study has shown that psychopathic people have a bigger striatum area in their brain
Neuroscientists using MRI scans discovered that psychopathic people have a 10% larger striatum, a cluster of neurons in the subcortical basal ganglia of the forebrain, than regular people. This represents a clear biological distinction between psychopaths and non-psychopathic people.
Neuroscientists from Nanyang Technological University (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, scientists discovered that the striatum, an area of the forebrain, was 10% bigger in psychopathic people compared to a control group of individuals with low or no psychopathic traits.
Psychopaths, or those with psychopathic qualities, are people who have an egotistical 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 forebrain, the subcortical region of the brain that encompasses the whole cerebrum, coordinates numerous elements of cognition, including motor and action planning, decision-making, motivation, reinforcement, and reward perception.
Previous research has shown that psychopaths have overactive striatum, but the influence of its size on behavior has yet to be confirmed. The new research demonstrates a significant biological difference between people who exhibit psychopathic tendencies and those who do not. While not all people with psychopathic qualities end up violating the law, and not all criminals satisfy the criteria for psychopathy, there is a strong association. There is also significant evidence that psychopathy is associated with more aggressive behavior.
The understanding of the role of biology in antisocial and criminal behavior may help improve existing theories of behavior, as well as inform policy and treatment options. To conduct their study, the neuroscientists scanned the brains of 120 participants in the United States and interviewed them using the Psychopathy Checklist-Revised, a psychological assessment tool to determine the presence of psychopathic traits in individuals.
Assistant Professor Olivia Choy, from NTU’s School of Social Sciences, a neurocriminologist who co-authored the study, said “Our study’s results help advance our knowledge about what underlies antisocial behavior such as psychopathy. We find that in addition to social environmental influences, it is important to consider that there can be differences in biology, in this case, the size of brain structures, between antisocial and non-antisocial individuals.”
Assistant Professor Olivia Choy, a neuroscientist from NTU’s School of Social Sciences, currently presenting diagrams of the human striatum. Credit: NTU Singapore