While studying the PET scans of the mentally ill, neuroscientist James Fallon discovered an "obviously pathological" scan in his files that correlated with psychopathic tendencies, or low frontal and temporal lobe activity in areas related to empathy and morality. The scan, to his surprise, was of his own brain.

Smithsonian magazine reports on the eerie findings that Fallon made in Oct. 2005 while conducting a research project at the University of California, Irvine.

"I was looking at many scans, scans of murderers mixed in with schizophrenics, depressives and other, normal brains," Fallon told Smithsonian. "Out of serendipity, I was also doing a study on Alzheimer's and as part of that, had brain scans from me and everyone in my family right on my desk."

Not only did his own brain scan show signs of psychopathy, a personality disorder characterized by a diminished capacity for remorse and lack of self-control, Fallon discovered after undergoing a series of genetics tests that he has relations to seven alleged murderers, including the infamous Lizzie Borden, known for being accused of killing her father and stepmother with an axe in 1892.

"I've never killed anybody, or raped anyone," he said. "So the first thing I thought was that maybe my hypothesis was wrong, and that these brain areas are not reflective of psychopathy or murderous behavior."

Fallon, however, has high-risk alleles for aggression, low empathy and violence, including an allele for a serotonin transporter protein. He is, however, what some call a "pro-social psychopath," or someone who has trouble feeling true empathy for others yet is able to maintain socially acceptable behavior and relationships.

"I'm obnoxiously competitive. I won't let my grandchildren win games. I'm kind of an asshole, and I do jerky things that piss people off," Fallon explained. "But while I'm aggressive, but my aggression is sublimated. I'd rather beat someone in an argument than beat them up."

Psychopathy is not a formal diagnosis in the "Diagnostic and Statistical Manual of Mental Disorders" due to the wide range of symptoms associated with the disorder.

Fallon says that he had a loving, supportive childhood, which may have contributed to his ability to act socially acceptable, although he argues that free will also plays a role in his behavior as well as genetics and environment. 

"Since finding all this out and looking into it, I've made an effort to try to change my behavior," Fallon told the magazine. "I've more consciously been doing things that are considered 'the right thing to do,' and thinking more about other people's feelings. At the same time, I'm not doing this because I'm suddenly nice, I'm doing it because of pride-because I want to show to everyone and myself that I can pull it off."

Click here to see James Fallon's PET brain scan as compared to a "control" brain.