The brains of psychopaths are different to those of normal people, according to a growing body of evidence being studied by neuroscientists. In the wake of last Friday's school massacre in Newtown,Connecticut, speculation mounts about the mental state of the gunman, Adam Lanza, and although little is known at this stage, scientists say it may be possible in the future to identify potential murderers through structural abnormalities in their brain.
NEWTOWN, CONNECTICUT, UNITED STATES (DECEMBER 14, 2012) (NBC) - As the U.S. tries to come to terms with last Friday's slaying of 26 people, including 20 children, at an elementary school thoughts are turning to the reasons behind gunman Adam Lanza's motives and his mental state. Some will undoubtedly label the 20-year-old killer a 'psychopath', although it will be some time before definitive judgements can be made on the killer's mental condition.Mental diagnoses have improved in recent years, as high-profile neuroscientists studying brain scans of violent criminals find more evidence that psychopaths have structural abnormalities in their brains.
James Fallon, of the University of California-Irvine, has studied the brains of psychopaths for almost two decades. Speaking at his California home recently Fallon told Reuters that the limbic cortex - or outer part of the brain - is underdeveloped in psychopaths.
"The part of the brain that's under-functioning in psychopaths, including psychopathic killers, generally it's called the limbic cortex. The cortex is the outer part of the brain, it's all over - down here and up above. The limbic cortex, limbic means emotional - it controls the emotional life that you have. And that is not so much out here. This is more for thinking, cognition, cold cognition, rational thought - this stuff up here. The stuff that's deep and quite old, is this orbital cortex. Now the orbital cortex, orbital means eyes so it's above the eyes," he said.
He added: "They all have the same underlying pattern, which is damage or loss of function to the orbital cortex, right above the eyes, and to the front of the temporal lobe - this whole limbic or emotional cortex. That's shaped like a "C" in the brain. And I noticed it was in all of them, so some of them only had that damage. And all of those that I looked at they turn out to be psychopaths and in this case they were murderers too. Some rapists, but psychopathic, really bad criminals."
Fallon made a startling discovery six years ago after his mother informed him that his great-grandfatherThomas Cornell was hanged in 1667 for murdering his mother. That line of Cornells produced seven other alleged murderers. After studying his own brain he discovered that he himself has psychopathic traits.
"This area is quite normal but that the area of the brain here, the orbital cortex, and this cingulate or limbic cortex that controls emotion and impulsivity and morality…it's turned off. And that is my brain as it turns out. And that's why I probably do have some of the traits of a psychopath," he said.
Across the Atlantic researchers at King's College London's Institute of Psychiatry have conducted similar studies on 44 violent adult male offenders already diagnosed with anti-social personality disorders. Blackwood's team used magnetic resonance imaging (MRI) to scan the brains. The study, led by Nigel Blackwood, showed differences in psychopaths' brains mark them out not just from healthy non-offenders, but from other violent criminals with anti-social personality disorders (ASPD).
Of the 44 men scanned, 17 met the diagnosis for ASPD plus psychopathy and 27 did not. The researchers also scanned the brains of 22 healthy non-offenders. The results showed that the psychopaths' brains had significantly less grey matter in the anterior rostral prefrontal cortex and temporal poles than the brains of the non-psychopathic offenders and non-offenders.
These areas of the brain are important for understanding other people's emotions and intentions, and are activated when people think about moral behaviour, the researchers said.
Blackwood said the childhood of psychopaths was often crucial. "The studies that have been done in our lab looking at callous and emotional children are in children at 9, 10, 11. And we can show brain differences, but we as yet don't know the predictive power of those differences. So someone with quite a bit of grey matter volume loss; are they the ones most likely to go on to be adult psychopaths, for example?," said Blackwood.
"It's always going to be an interaction between their genetics and their childhood environment. Certainly in our own study, the psychopathic men reported a greater degree of childhood maltreatment than the non-psychopathic anti-social men. So perhaps there is an interaction between genetic predisposition, childhood maltreatment, other brain insults," he said.
The findings have implications for the justice system, because linking psychopathy to brain function raises the prospect of arguing a defence of insanity. Interest in what goes on inside the heads of violent criminals has been sharpened by the trial of Anders Behring Breivik, the Norwegian who massacred 77 people last July. Two court-appointed psychiatric teams who examined Breivik came to opposite conclusions about his mental health.
Interest in the mental state of James Holmes, the alleged perpetrator of a mass shooting in July at a cinema in Aurora, Colorado, has also been high, particularly after the transmission of footage showing his strange behaviour while in court .
Blackwood says further studies could lead to lawyers in future trials making pleas of diminished responsibility for their clients if their brains were shown to be that of a psychopath. "Just as juries accept now that illnesses like schizophrenia do have an impact of someone's criminal responsibility, perhaps with another five to ten years of studies like ours, with an increasingly sophisticated understanding, they'll begin to understand and begin to think about issues like diminished responsibility in those who are psychopathic," he said.
Other experts have said Blackwood's findings add to evidence that psychopathy is a distinct neurodevelopmental brain disorder.
Questions regarding the mental health of Adam Lanza will doubtless intensify, while the devastated community of Sandy Hook continue to grieve the loss of life from the second-deadliest school shooting in U.S. history.