What makes a psychopath?

In a quest to determine whether it comes down to nature or nurture, a team of neurologists in China has discovered that certain brains are hardwired to show psychopathic behaviors, including aggression and rule-breaking.

The first-of-its kind study examined how the brain’s structure connects psychopathy, a diagnosable psychological disorder, with real-world actions.

After analyzing the brain scans of more than 80 people who reported having certain psychopathic traits, though not officially diagnosed as psychopaths, researchers found those with stronger tendencies toward aggression, impulsivity, and lack of empathy, showed distinct structural brain connectivity compared to individuals with milder traits.

Those traits common in psychopaths were in turn associated with behaviors including substance abuse and violence. 

The research suggests that the brains of people with these qualities are wired differently, with some pathways supercharged while others are weakened, potentially leading to harmful or disturbing behaviors. 

Roughly one percent of Americans have been diagnosed psychopaths, equating to about 3.3million people.   

Not all people who have psychopathic traits are true psychopaths, though. These characteristics exist on a spectrum on which people show symptoms to varying degrees without being clinically diagnosed or becoming violent.  

A team of neurologists in China has discovered that certain brains are hardwired to show psychopathic behaviors, including aggression, rule-breaking, and criminal behavior (stock image)

Typically, research into psychopathy studies how different brain regions communicate with each other. 

But the Chinese researchers focused on structural connectivity; the nerve fibers that link different regions, the integrity of fiber bundles, and weaker or thicker white matter pathways. 

Rather than focusing on how different parts of the brain fail to communicate, structural connectivity examines why they fail.

Researchers relied on 82 people’s brain scans. The people were sourced from the Leipzig Mind-Body Database, a repository of neuroimaging data collected from adults in Leipzig, Germany. 

They documented each person’s psychopathic traits using the Short Dark Triad Test, a questionnaire consisting of 27 questions that capture people’s narcissism, manipulative tendencies, and psychopathic traits, such as a lack of empathy.

People had to rate themselves on a five-point scale from strongly disagree (one) to strongly agree (five). Higher scores indicated more psychopathic traits.

Then, researchers assessed people’s behaviors using the Adult Self-Report.

Researchers administered the Dark Triad test, which captures people’s narcissism, manipulative tendencies, and psychopathic traits, such as a lack of empathy. People with so-called ‘dark triad personality traits’ share similar facial features and expressions

It evaluates a range of emotional and behavioral actions, specifically measuring aggressive, rule-breaking, and intrusive behaviors such as unwanted personal questions or overstepping physical boundaries.

A higher score indicated more severe external behaviors.

Scientists used each person’s MRI data to map out how different brain areas are physically connected.

The study identified two key brain connections tied to impulsive and antisocial behaviors in people who possessed psychopathic traits based on their questionnaire answers. 

‘Psychopathic traits were primarily associated with increased structural connectivity within frontal (five edges) and parietal (two edges) regions,’ the researchers said.

In the positive network, in which brain connections are strengthened as psychopathic traits increase, stronger connections were clustered in brain regions governing decision-making, emotion, and attention.

These included pathways that link emotion and impulse control, which may explain blunted fear and reduced empathy in psychopaths. 

It also included the area involved in social behavior, which could cause a psychopath to understand emotion but not feel it. 

Some people’s psychopathic behaviors can be foreseen in their faces. One law enforcement officer said Idaho murderer Bryan Kohberger has ‘resting killer face’

And connection correlated with more impulsive actions.

In the negative network, in which connections weaken with stronger psychopathic traits, researchers saw weak links in the regions critical for self-control and focus, translating to psychopaths’ tendency to hyper focus on their self-serving goals while ignoring how their actions affect others.

Researchers also found unusual connections between areas used for language and understanding words. 

Given that psychopaths are adept at manipulation, this could indicate neural wiring optimized for strategic, controlling communication rather than genuine communication.

The team also found a strong connection between brain regions responsible for reward-seeking behavior and areas for decision making, which could explain why psychopaths often chase immediate gratification, even when it harms others.

Dr Jaleel Mohammed, a psychiatrist in the UK, said: ‘Psychopaths do not care about other people’s feelings. In fact if you ever approach a psychopath to tell them about how you’re feeling about a situation, a psychopath will make it very clear that they could not care less.

‘They literally have a million things that they would rather do than listen to how you feel about a situation.’

The findings were published in the European Journal of Neuroscience.