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Research on some of the worst criminals suggests brain chemistry, abnormalities play a part

Can murderously depraved behaviour be biologically based, some glitch or misfiring in the brain that turns people into callous, manipulative and less-than-human monsters?

If the charges against Luka Rocco Magnotta - the Montreal porn actor accused of killing and allegedly eating parts of his victim before sending other body parts through the mail - can be proven, the question for many will be: How could a person be capable of such depravity? And is there any way to detect the psychopaths among us?

Experts say there is no neurological litmus test for psychopathy.

However, over the past decade, there has been a rush to research the brains of society's worst criminals, with a stream of studies linking psychopathic behaviour to physical abnormalities.

Scientists from King's College London claim to have found what they have described as the strongest evidence yet that psychopaths have abnormalities in key areas of their "social brains."

For their experiment, the team slid 44 male violent offenders - murderers and rapists among them, 17 fitting the diagnosis for psychopathy - through an MRI.

According to their brain scans, the prisoners with psychopathic traits had significantly smaller amounts of grey matter in regions associated with processing empathy, moral reasoning and "self-conscious" emotions, such as guilt and embarrassment.

High on a psychopath's list of traits is an inability to empathize with the distress of others.

"They are utterly without compassion," says Elliott Leyton, a professor emeritus at Memorial University and author of the book, Hunting Humans. "Other people are just things they use for their own pleasure."

Other recent studies have implicated the amygdala - the area associated with aggression. Lesions in another brain region - the orbitofrontal cortex - have also been linked with some of the classic signatures of psychopathy, including pathological lying, irresponsibility, shallowness and lack of emotion, guilt or remorse. Still others have found abnormalities in the swath of white matter connecting the two brain regions.


Genetics may play a role. One gene in particular has been implicated - MAO-A, which produces an enzyme that breaks down serotonin, which affects mood and can have a calming effect. Sometimes called the "warrior gene," it's been theorized that the calming effects of serotonin may not always be effective in people born with a variant of the gene.

Stephen Benning is an assistant professor of psychology at Vanderbilt University in Nashville, Tenn. Two years ago, he was part of a team that reported in the journal Nature Neuroscience that the brain of psychopaths may be wired for rewards.

Brain scans showed that people high in "impulsive anti-sociality" - a combination, Benning says, of "meanness" and disinhibition - showed greater activity in parts of the brain related to anticipating and expecting rewards.

When those rewards don't come nearly as frequently as wanted, they become more aggressive, more frustrated and "more alienated toward the world," Benning said.

"Once you reach a certain level of frustration, people may essentially feel like, 'Forget it, it's not worth trying to achieve what I want by normal, societally acceptable means. I'm going to go out and hurt some-one to get what I want.' "


Other studies suggest psycho-paths' brains have an enhanced ability to sense certain emotions - in particular, fear. They seem better able to pick up cues of vulnerability or weakness, making them, in a sense, a natural-born predator.

At this stage, experts can only speculate based on news reports, but several said Magnotta exhibits some of the key characteristics of the "prototypical psychopath." He is also a classic thrill-seeker, says psychologist Dr. Frank Farley, who coined the term "Type T [thrill seeker]" personality.

"I think a lot of killing involves more thrill value than we acknowledge," he said.

Magnotta allegedly ate parts of his victim, suggesting, if true, that, "he pushed every thrill button for a psychopath that you can possibly do," says Farley. "You kill somebody and you go the next step. How exciting is it to taste them, to eat them?"


But not all are comfortable with the field's sudden rush to the brain. Farley, an Edmonton native and past president of the American Psychological Association, worries a new kind of reductionism is at play. "We're trying to reduce very complex human behaviours to some precise little process in the brain," he says.

It doesn't wash, he says. "Humans have evolved in a complex social world of relationships, families, upbringing and human connections," says Farley, a psychologist at Temple University in Philadelphia.

"It can't be boiled down to a microscopic-sized area of the brain," he argues, or one of the thousands of biochemical activities of the brain.

Biology can be a part of it, he says, but it's the social side, "the social influences, the nurturing influences that, in my view, dominate."

For example, abuse in childhood is common among those with psychopathic traits - abuse so relentless, "he has to anesthetize himself against it," says Leyton.

"And in the process of anesthetizing himself, he also loses any touch of his own humanity."

According to Farley, scholars have argued that psychopaths feel deeply about nothing.

But if most of murderous behaviour was biologically based, the worst offenders would be more alike than they are, he says.

U.S. serial killer John Wayne Gacy, a former construction contractor and part-time party clown, was executed in 1994 after confessing to the sexual assault and murder of 33 young men and teenage boys in the 1970s.

Like Magnotta, he was an exhibitionist, Farley said. "He just did it in the pre-digital age."

Jeffrey Dahmer murdered 17 men and boys. "He dismembered them and ate them and stored their skulls in his refrigerator," Farley said. But Dahmer was a quiet non-exhibitionist.

Serial killer and rapist Ted Bundy had the charm of a psychopath. "Some people even wept at his execution, for God's sake," said Farley. "These murderers are so extreme, so unusual in their behaviour - Would his [Magnotta's] brain be the same as the brain of the elegant Ted Bundy, or the blue-collar Gacy or the introvert Dahmer? Their brains may be different on all sorts of significant levels."


Many experts agree that it's not one or the other, nature or nurture, but rather a combination.

"People shouldn't be panicked that there's a cannibal lurking around every corner," says Leyton.

"It's just a combination of biological, biochemical, personal psychology and social environment that come together, very rarely, to produce this kind of abomination."

He called cannibalism the ultimate desecration of a victim. "How better to destroy and obliterate something that you're raging at than to do that?"

According to Dr. Robert Hare, a professor emeritus of psychology at the University of British Columbia and creator of the Hare Psychopathy Checklist, which estimates "the extent to which a given individual matches the prototypical psychopath," psychopaths comprise perhaps one per cent of the Canadian population.

Observers say it would be a logistical nightmare to attempt to screen for people capable of committing such rare and extraordinary vile acts.

And it's not even clear what the brain abnormalities mean. How much deviation from "normal" would be needed for a person to be at risk of deviancy or a real dysfunction?

Most psychopaths are not the murderous Hannibal Lecter, said Benning, of Vanderbilt University. They're not even necessarily criminals.

But they do contribute to "a whole lot of heartbreak and ruined lives."

"There are so many societal consequences to individuals who cannot control their behaviour, who are lacking in empathy and who are aggressive toward others," he says.

They are utterly charming, he adds. And you can't see them coming.