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 machine.
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, professor emeritus at Memorial University and author of the book Hunting Humans. "Other people are just things they use for their own pleasure."
Stephen Benning is an assistant professor of psychology at Vanderbilt University in Nashville, Tennessee. 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 antisociality" -- 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 someone to get what I want.' "
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.
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."
-- Postmedia News