In a new study in the Netherlands, researchers wanted to know if they could detect a visible difference between the brains of psychopaths and non-psychopaths, and even more distinctly, between the brains of criminal psychopaths and non-criminal psychopaths.
They discovered that while all people with psychopathic tendencies appear to be extremely sensitive to reward, a key difference between those who engage in criminal activity and those who don’t is an additional lack of self control.
Therefore, the hallmark of a psychopathic criminal is having a strong focus on reward combined with a lack of self-control, according to the researchers from the Donders Institute and the Department of Psychiatry at Radboud University Medical Center.
For the study, the researchers conducted tests on 14 convicted psychopathic individuals, as well as 20 non-criminal individuals, half of whom had a high score on the psychopathy scale. The participants were asked to perform tasks while their brain activity was measured in an MRI scanner.
“We saw that the reward centre in the brains of people with many psychopathic traits (both criminal and non-criminal) were more strongly activated than those in people without psychopathic traits,” said researcher Dirk Geurts in the Department of Psychiatry.
“It has already been proved that the brains of non-criminal individuals with psychopathic traits are triggered by the expectation of reward. This research shows that this is also the case for criminal individuals with psychopathic traits.”
Another interesting difference was discovered between non-criminal people with multiple psychopathic traits and criminal people with psychopathic traits.
“There is a difference in the communication between the reward centre and an area in the middle of the forebrain. Good communication between these areas would appear to be a condition for self-control,” said Geurts.
“Our results seem to indicate that the tendency to commit an offence arises from a combination of a strong focus on reward and a lack of self-control. This is the first research project in which convicted criminals were actually examined.”
Psychopathy consists of several elements, including a lack of empathy and emotional involvement as well as impulsive and severely antisocial, egocentric behavior.
“Especially the latter character traits seem to be connected with an excessively sensitive reward centre. The presence of these impulsive and antisocial traits predict criminal behaviour more accurately than a lack of empathy,” said Robbert-Jan Verkes, Professor of Psychiatry and research coordinator.
While the cause of these brain abnormalities may be partly hereditary, it is more likely that abuse and severe stress during the formative years play a significant role. Follow-up studies will provide more information.
The findings are published in the journal Social Cognitive and Affective Neuroscience.
Source: Radboud University