The difference between you and a psychopath

The amygdala, of course, is the brain's fear center -- an ancient evolutionary development that's worked to keep homo sapiens sapiens alive if not thriving for hundreds of thousands of years. A sudden movement, a sharp sound: The amygdala reacts at the slightest provocation. It's up to the prefrontal cortex, the seat of reasoning, of "executive function," to quiet the amygdala, once it's determined that the movement or sound doesn't represent an actual threat. In the case of people who panic, it's believed that the prefrontal cortex doesn't have the "oomph" needed to shut down the amygdala's warning screech as appropriate. Why else would you panic because you're riding an elevator or driving over a bridge?

If you panic, you may have wondered what it would be like to be unburdened by an amygdala. Maybe it would be awesome; maybe you'd feel free to become the you you've always wanted to be. Maybe it would make you fearless if a bit odd.

Or maybe it would make you a psychopath. At least, that'a conclusion reached in a recent article in the Guardian UK, an excellent piece called How to spot a psychopath:

In the mid-60s, Hare was working as a prison psychologist in Vancouver. He put word around the prison that he was looking for psychopathic and non-psychopathic volunteers for tests. He strapped them up to various EEG and sweat- and blood pressure-measuring machines, and also to an electricity generator, and explained to them that he was going to count backwards from 10 and when he reached one they'd receive a very painful electric shock.

The difference in the responses stunned Hare. The non-psychopathic volunteers (theirs were crimes of passion, usually, or crimes born from terrible poverty or abuse) steeled themselves ruefully, as if a painful electric shock were just the penance they deserved. They were, Hare noted, scared.
"And the psychopaths?" I asked.

"They didn't break a sweat," said Hare. "Nothing." The tests seemed to indicate that the amygdala, the part of the brain that should have anticipated the unpleasantness and sent the requisite signals of fear to the central nervous system, wasn't functioning as it should. It was an enormous breakthrough for Hare, his first clue that the brains of psychopaths were different from regular brains.