The Psychopathic Brain



Psychopaths have different brains than the rest of us. That much is obvious. But what does it feel like?

In a new study, individuals diagnosed with psychopathy (egotistical, antisocial, and devoid of empathy, guilt, or remorse) were compared to individuals with low or zero scores on the standard checklist of psychopathic traits. Those with psychopathy showed a nearly 10 percent increase in the size of their striatum.

The striatum (I have to look it up) plays a role in planning actions, making decisions, and seeking rewards. The researchers believe this finding could account for the impulsivity and stimulation seeking that characterize people with psychopathy—and thus explain the chilling wrongness of their decision-making.

If a serial killer, for example, is overwhelmed by the need for some sort of gratification or reward and cannot check the impulse…more people will die. The stakes need not be that high, though: “We have always known that psychopaths go to extreme lengths to seek out rewards, including criminal activities that involve property, sex, and drugs,” said study co-author Adrian Raine of the University of Pennsylvania. “We are now finding out a neurobiological underpinning of this impulsive and stimulating behavior.”

Thrill-seeking is genetic. So, in a sense, is the cruelty it sometimes requires. People recoil from such insights, seeing them as excusing away the behavior. But until we understand its origins, we can do nothing to stop it. Social predators will continue to manipulate, damage, or kill ruthlessly, because what they crave is an excitement no tamer hobbies can provide. And when you have a supersized reward center with no checks and balances, those cravings can be insatiable.

The rest of us can stop worrying if we have ever been so mad, we wanted someone dead. We do not want enough. People with psychopathy would crave it the way someone who is suffocating craves air.

This is useful to know.

Still, the study only did MRIs on 108 people and, using the standard checklist, turned up 18 who met the criteria for psychopathy (those who do being notoriously difficult to enroll in an altruistic study). Leery of the small sample size, I check with two postdoc researchers in neuropsychiatry here at Washington University.

“I think it’s fair to say that the results can be characterized as ‘intriguing, but not definitive,’” says David Baranger. What is most intriguing, the marked difference in the size of the striatum, is what concerns him. The reported difference is “larger than anything seen in other psychiatric disorder,” he says, and this leaves him skeptical. He is not even sure the analysis was sufficiently powered to reach those results.

On the other hand, I think privately, psychopathy is markedly different from just about any other brain disorder. As a layperson without a clue how these results are calculated, I am now left only with dangerous folk wisdom.

And questions.

If we prove that behavior we have called evil for millennia is just a biological quirk, will that make the horror easier to accept? Or will we then switch to loathing our own species instead of scapegoating the supernatural?

Alexander Hatoum, one of Baranger’s colleagues, slows me down again: a recent study that Wash.U. researchers published in Nature showed that most imaging studies require much larger sample sizes than what are used. “It is also important to note that there currently is no way to diagnosis psychiatric patients with MRI,” Hatoum adds.

That makes sense. Even the sort of scan that shows how the brain reacts to certain information would not tell you what value it attached or what behavior it was unwilling (or unable, and there is the rub) to inhibit. But if you already have the diagnosis, surely an MRI showing physiological differences—if you have a large enough sample size—could be instructive?

Back in 2011, a study at the University of Wisconsin-Madison showed “reduced connections between the ventromedial prefrontal cortex, the part of the brain responsible for sentiments such as empathy and guilt, and the amygdala, which mediates fear and anxiety.” I assume that means that in a stressful situation—like, say, murdering somebody—empathy and guilt do not kick in. But what gets somebody to the point of the murder in the first place? Is a simple lack of empathy sufficient motivation to erase a stranger’s life?

That 2011 study was small, too—only twenty offenders, all of whom met the criteria for psychopathy, compared with a control group. “Will we ever be able to study enough psychopathic brains to reach a conclusion?” I ask the Wash.U. researchers, expecting them to say no. Instead, Hatoum mentions the ENIGMA consortium, which is piecing together small studies in a meta-analysis. That could help us understand how the brain is configured and what regions or anomalies are associated with psychiatric disorders.

So it might be only a matter of time until we know who or what to blame for the “evil” among us. We already know these findings intuitively; we speak of people as broken, meaning beyond repair, or laughingly say they’re just “not right.” They are “twisted,” “messed up,” a “bad seed.” These are all physical states. Yet the magnitude of their cruelty, the deadly cold of their responses to others, feels so unnatural that we brand them “evil” or “demonic.” Because they coolly seize power over others, we deduce that they are in complete control of their own behavior.

But if they are not—and if the cause is entirely physiological—what then? We still have no clue about the origin of a larger striatum. Can context still make a difference, the way a highly structured, disciplined environment helps a child with ADHD learn to control impulses? Would knowing someone has a flawed brain make us more compassionate?

I should have consistently referred to “people with psychopathy” rather than “psychopaths,” but I have a hard time using people-first language in this context. Maybe the more we learn, the more I will soften. Surely there are degrees of psychopathy? How many times have I argued that a particular characteristic was innate and therefore the person should not be blamed or stigmatized? Logic cracks and breaks on the granite surface of psychopathy.

Logic, for example, would suggest sending someone whose behavior has a cause outside their control to a mental hospital instead of a prison. A psychopathic brain processes punishment differently anyway, which is why rehabilitation is nearly impossible. But we have no ready treatments to offer, no way to prevent them from doing more damage. Besides, I suspect we will eventually learn that there is a physiological underpinning for virtually all criminal behavior. The real question is how compulsive that behavior is, how much control can be mustered. And I have no idea how a brain scan could ever show that.

All we are measuring is our own helplessness.


Read more by Jeannette Cooperman here.