Neuroscientist James Fallon found something shocking when he was looking at brain scans of serial killers for research, and brain scans of his family for signs of disease. According to the scan, his own brain was no different than that of a psychopath. The discovery opened up a new world of research, TED talks and his recent book, The Psychopath Inside: A Neuroscientist’s Personal Journey into the Dark Side of the Brain.
Fallon estimated that, like himself, five to six percent of us are "near psychopaths," on the border.
Fallon joined WNPR's Where We Live to talk about brain science and the mind of a psychopath, just a few days after the final police report on the Newtown shootings was released. Through the report, we learned a bit more about Lanza: Beyond his primary diagnosis of Asperger Syndrome, he also was diagnosed with Obsessive Compulsive Disorder, something written about extensively in Fallon’s book. We learned more about Lanza’s social detachment, and lack of the kind of “nurturing” environment that James Fallon had growing up. Finally, that through his diagnosis of Asperger syndrome, Lanza may have lacked “theory of mind,” the ability to see others as real people.

Do these diagnoses mean that Lanza was a psychopath? That answer is not easy to know, according to Fallon -- partly because "psychopathy" (or "sociopathy") is not one exact thing. It "is not even included in the official manual for psychiatry and psychology, the DSM-IV," he said. "It overlaps with too many other things," like malignant narcissism, and antisocial personality disorder (ASPD).
Fallon would consider only one percent of women and two percent of men to be "categorical" psychopaths -- the criminal, serial killer kind. He said it's hard to know how many, "because there are so few of them, so few people who do these horrendously violent things that are hard to understand." He said it's a field that is very understudied. "People who study this are all kind of agreeing what the problem is," he said. "But just because a number of the experts agree on it doesn't mean it’s true, because we haven’t really tested it."
Fallon estimated that, like himself, five to six percent of us are "near psychopaths," on the border. So what's the difference? And what could sway a near-psychopath to be a categorical psychopath?
The key to this could lie in our epigenome -- in early stressors that release chemicals that turn our genes on or off. Fallon looks to two "critical periods": right after fertilization, and right around the time of birth, up to a year and a half. Abandonment, physical or sexual abuse, and maternal stress can all trigger changes in our DNA.
In the struggle to understand why Lanza did such horrible things, we still don't have answers. But Fallon thinks that genetics and neuroscience could hold the key to predicting these behaviors in the future.
"A lot of that information on early behavior," he said, "what really happened in the family, and getting the genetics, is almost impossible. The question is, 'Could we have known?' If we knew about Adam’s genetics and his brain pattern, and somebody had been alerted to it, could we have predicted, based on his early behavior and genetics? The answer is probably yes."