Structural brain differences appear to distinguish psychopaths from individuals without psychopathic traits, new research shows.
Using MRI, researchers found that the striatum was about 10% larger on average in adults with psychopathic traits than in matched control persons and that this relationship was mediated by stimulation seeking and impulsivity.
The striatum is a subcortical region of the forebrain involved in the cognitive processing of reward-related information and motivational aspects of behavior.
"Our study's results help advance our knowledge about what underlies antisocial behavior such as psychopathy," co-author and neurocriminologist Olivia Choy, PhD, with Nanyang Technological University in Singapore, said in a news release.
"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," Choy added.
The study was published online March 6 in the Journal of Psychiatric Research.
Antisocial, Egocentric
Individuals with psychopathic traits typically have an egocentric and antisocial personality. They generally lack remorse for their actions or empathy for others and often have criminal tendencies.
Some prior research suggests links between psychopathy and an overactive striatum, but it was unclear what role striatal volume plays in this behavior.
For the study, investigators assessed striatal volume using MRI in 120 adults living in the community, and they assessed psychopathy using the Psychopathy Checklist – Revised.
