Brains and Killers

Brains and Consciousness:

A Neuroscientist you may have heard of, James Fallon, reveals two things: first, that his family includes a number of murderers, including alleged killer Lizzy Borden. Second, that his brain scan says he's a psychopath.

"And I took a look at my own PET scan and saw something disturbing that I did not talk about," he says.

What he didn't want to reveal was that his orbital cortex looks inactive.

"If you look at the PET scan, I look just like one of those killers."

So he tested this with another marker that reveals murderous behavior.

Along with brain scans, Fallon also tested each family member's DNA for genes that are associated with violence. He looked at 12 genes related to aggression and violence and zeroed in on the MAO-A gene (monoamine oxidase A). This gene, which has been the target of considerable research, is also known as the "warrior gene" because it regulates serotonin in the brain. Serotonin affects your mood — think Prozac — and many scientists believe that if you have a certain version of the warrior gene, your brain won't respond to the calming effects of serotonin.

Fallon calls up another slide on his computer. It has a list of family members' names, and next to them, the results of the genotyping. Everyone in his family has the low-aggression variant of the MAO-A gene, except for one person.

"You see that? I'm 100 percent. I have the pattern, the risky pattern," he says, then pauses. "In a sense, I'm a born killer."

But he isn't, of course, a killer at all. Not only that, he doesn't have the impulse control problems -- one doesn't succeed at neuroscience if one cannot delay gratification, and he has a wife who's known him since he was 12 and feels entirely comfortable with him.

He has a theory that you need a third factor -- abuse.

Significantly, he says this journey through his brain has changed the way he thinks about nature and nurture. He once believed that genes and brain function could determine everything about us. But now he thinks his childhood may have made all the difference.

With respect to the scientist, that's not a convincing answer. It would be adequate to explain the presence of a gene in someone with no wicked impulses; but it doesn't adequately explain the brain scan. A gene may be a predisposition to developing in a certain way; untriggered, that potential may simply not develop.

A brain scan, though, shows what is happening in your brain right now. His brain really is showing low activity in the impulse-control region; and yet his impulse control is perfectly fine.

This suggests that brain activity isn't as closely related to consciousness as we have come to believe. Indeed, the leading theory in "philosophy of mind" is close to his own "genes and brain function... determine everything" about our conscious experience; or as that is put in philosopher-speak, "mental states supervene on brain states."

It may be that we aren't looking at the right part of the brain scan; it could be that "happy childhood" people have another part that is more active than "unhappy childhood" people with the same markers. In that case, his theory could prove out.

The alternative is that there is something to the mind besides the brain. That's always been my sense of where the truth lies; but it will be something of a revolution among both scientists and philosophers if it proves out.