Psychopaths are known for their selfishness, callousness, and violence. These antisocial personality traits are often baffling to the rest of us, but could brain differences help to explain them? And, more importantly, do such hardwired differences help or hinder treatment?
man in suit with knife
Some psychopaths are killers, but some make for great businessmen, researchers say.

Psychopathy is generally considered to be a personality disorder.

Although the Diagnostic and Statistical Manual of Mental Disorders (DSM) does not formally acknowledge psychopathy as a standalone condition, it incorporates it under the wider “antisocial personality disorder.”

But what is a psychopath? In 1993, Canadian psychologist Robert Hare, the creator of the famous Hare Psychopathy Checklist, defined psychopaths as “social predators who charm, manipulate, and ruthlessly plow their way through life.”

“Completely lacking in conscience and feeling for others,” he goes on to say, psychopaths “selfishly take what they want and do as they please, violating social norms and expectations without the slightest sense of guilt or regret.”

Does any of this sound familiar? The stereotypical portrait of the psychopath may call to mind such fictional characters as Hannibal Lecter, or even real personalities such as the serial killers Ted Bundy or Jeffrey Dahmer. However, some argue that most psychopaths live among us.

According to recent estimates, just below 1 percent of non-institutionalized males in the United States are psychopaths.

Despite this small percentage, people who have psychopathy are 20–25 times more likely to be incarcerated than non-psychopaths, and half of all violent crimes in the U.S. are committed by psychopaths.

That said, if you feel as though this definition could easily fit your boss or your neighbor, you might be right. In his book Snakes in Suits, Hare argues that psychopaths are more numerous than we might think, many of them fitting perfectly, and even thriving in, the corporate world or that of politics.

“[N]ot all psychopaths are killers,” Hare writes. “They are more likely to be men and women you know who move through life with supreme self-confidence — but without a conscience.”

In this article, we will attempt to find out exactly what goes on inside the brain of such supremely confident yet conscienceless people. Is there such a thing as a neurological explanation for callousness? Can anything be done to correct it?

When the brain is not ‘equipped’ for empathy

“A marked lack of empathy is a hallmark characteristic of individuals with psychopathy,” explains Jean Decety, the Irving B. Harris Professor in psychology and psychiatry at the University of Chicago in Illinois, and a world-renowned expert on the neuroscience of empathy.

ventromedial prefrontal cortex
The ventromedial prefrontal cortex (depicted here) is key for our moral decision-making. Image credit: Patrick J. Lynch, medical illustrator, via Wikimedia.

Several studies have suggested the neural basis for empathy is either faulty or lacking altogether in the psychopathic brain.

Research has indicated that psychopaths might have an impaired mirror neuron system — that is, difficulties with the neurons that, in a healthy brain, activate both when we perceive someone else doing an action and when we do that same action ourselves.

Other, now classic, studies have found reduced volumes of gray matter in the brain’s so-called paralimbic system — the conglomerate of brain regions responsible for emotion regulation and self-control, setting goals, and staying motivated in the face of delayed gratification.

More recently, Prof. Decety has led several experiments that suggest that psychopaths simply lack the neural “equipment” for empathy.

He and his team scanned the brains of 121 inmates held in a U.S. medium-security prison while they were shown images of painful situations. The study participants were also assessed using the Hare Psychopathy Checklist-Revised (PCL-R).

When the participants deemed “highly psychopathic” were asked to imagine that the pain was inflicted on them, the relevant brain areas known to be linked with emotion processing and empathy for pain did “light up” in the functional (MRI) machine.

These brain areas are: the anterior insula, the anterior midcingulate cortex, somatosensory cortex, and the right amygdala.

However, when the highly psychopathic individuals were asked to imagine that somebody else was experiencing pain, the same brain areas failed to respond.

Also, the study found that the participants’ insulae and ventromedial prefrontal cortices (vMPFC) failed to connect when the participants had to take the perspective of another.

The vMPFC, also known as the “social hub” of our brain, is an area involved in empathetic decision making — that is, it helps us to weigh decisions that benefit either ourselves or others — and in attributing feelings and thoughts to other people.

But it seems that in the case of psychopaths, the neural circuits that would have to activate during empathy are just faulty, making psychopaths ill-equipped for this basic human emotion.

Are psychopaths just bad decision-makers?

Some have suggested that psychopaths are not evil, just…really bad at making decisions. Joshua Buckholtz, an associate professor of psychology at Harvard University in Cambridge, MA, and his colleagues scanned the brains of 49 inmates held in two medium-security prisons while asking them to complete a delayed gratification test.

This is a situation wherein they had to choose between receiving less money immediately or more money later on.

They found that a brain area called the ventral striatum — a region tied to evaluating the value of immediate rewards — was overly active in participants deemed highly sociopathic on the PCR-L scale. Psychopaths, then, might simply overestimate the value of their immediate rewards.

This finding also correlates with the aforementioned work regarding the key role of the vMPFC in psychopathy. The vMPFC, explain Buckholtz and his colleagues, controls the reward-processing ventral striatum.

So, if we want $100,000 but in order to get that we’d have to kill someone, our vMPFC can tell the ventral striatum, “Hang on a minute! You may want to reassess that trade-off — is it really worth taking someone else’s life for money? And can you bear the consequences of your actions?”

But Buckholtz and colleagues found that in psychopathic brains, the vMPFC and the ventral striatum are not communicating.

As he explains, “The striatum assigns values to different actions without much temporal context. We need the prefrontal cortex to make prospective judgments [about] how an action will affect us in the future — ‘If I do this, then this bad thing will happen.'”

[I]f you break that connection in anyone, they’re going to start making bad choices because they won’t have the information that would otherwise guide their decision-making to more adaptive ends.”

Joshua Buckholtz

“[Psychopaths are] not aliens, they’re people who make bad decisions,” Buckholtz concludes. Well, we might add, sometimes these are very, very, bad decisions.

Is testosterone to blame?

Overall, therefore, there seems to be a consensus among researchers that psychopathy is down to faulty brain circuits. But what causes these disconnects between brain areas? Some have suggested that the male sex hormone testosterone could be the culprit.

A study conducted by researchers led by Prof. Karin Roelofs, at the Donders Institute at Radboud University in the Netherlands, confirmed that the brains of psychopaths showed poor connectivity between the amygdala — the brain region key for processing emotions, especially fear — and the more “judging,” wiser prefrontal cortex.

What is more, the study found that these people also had very high levels of testosterone and lower activity in their prefrontal cortex. The overabundance of testosterone may explain why there are more male psychopaths than there are female ones.

“Psychopathic individuals,” write the authors of the study, “are notorious for their controlled goal-directed aggressive behavior. Yet, during social challenges, they often show uncontrolled emotional behavior.”

Prof. Roelofs and colleagues refer to this as the “paradoxical aspect of psychopathy.” Interestingly, the researchers say that their findings bring hope and inform future strategies for treating this aspect, which may be down to “a potential imbalance in testosterone function.”

But isn’t this too optimistic? The general consensus seems to be that psychopathy cannot be cured. However, that doesn’t stop us from asking, “Can it be treated?”

An incurable, yet treatable, condition

If psychopathic traits are so firmly rooted in our neural networks, does that mean that therapeutic interventions are doomed to fail? Not necessarily, researchers say.

young man behind bars
Treatment interventions in prisons have shown that young psychopaths can be rehabilitated.

Due to the brain’s neuroplasticity, Prof. Decety and colleagues suggest that both cognitive therapy and drugs may help to repair the broken “connections” between brain areas.

Prof. Roelofs and team are also optimistic. Often, they argue, psychopaths also have attentional deficits — for example, so if conditions such as attentional deficit disorder can be treated, why couldn’t psychopathy?

The greatest challenge of treating psychopathy, however, relies on the fact that psychopaths seem to be immune to punishment. Guiltless and remorseless, psychopaths do not seem to fear or learn anything from retribution, perhaps because of the broken connection between the brain’s amygdala and the prefrontal cortex.

However, a model that centers on positive reinforcement instead may work. Developed by the staff at the Mendota Juvenile Treatment Center (MJTC) in Madison, WI, the so-called Decompression Model is a cognitive-behavioral intervention that immediately rewards every positive action or gesture, no matter how small.

Additionally, the rewards are scalable. The highly psychopathic youth were told that if they persist with their positive behavior, the small reward they got at first — say, being told “well done” — can progress into some delicious dessert, and later on into the right to play video games, and so on.

Perhaps because the psychopathic brain is so centered on rewards, interventions such as the one at the MJTC yielded “staggering” results. In their intervention summary, the MJTC report:

The program had the greatest impact on serious violent offenses, reducing the risk of their incidence by about half. Youth in the treatment group were more than [six] times less likely to engage in felony violence than the comparison group youth.”

Impressively, young people who did not receive the MJTC treatment killed 16 people, whereas no homicides were registered in the intervention group.

But this is not the only intervention that has proved successful. In her review of existing studies, Lindsay Aleta Sewall — a researcher at the University of Saskatchewan in Saskatoon, Canada — says that “a growing collection of studies has found that psychopathic offenders who decreased their risk as a result of treatment, demonstrate lower rates of recidivism.”

Sewall also refers to research that makes a vital point; offenders who still score high on the PCL-R psychopathy scale after treatment does not mean that the treatment was unsuccessful. What we need to look at is recidivism.

In other words, it doesn’t matter so much whether psychopathy can be cured, as it does whether it can be managed.

Drawing on his own findings, Prof. Buckholtz explains, “The same kind of short-sighted, impulsive decision-making that we see in psychopathic individuals has also been noted in compulsive overeaters and substance abusers.”

And, just like in these people — although one can never be fully cured — perhaps with the right treatment, psychopaths can learn to lead normal lives, one day at a time.