The most reliable sign, the most universal behavior of unscrupulous people is not directed, as one might imagine, at our fearfulness. It is, perversely, an appeal to our sympathy.

We are all a little crazy.

The physical basis for sociopathy is approximately 50 percent inheritable, which sounds more dramatic than it probably is, because most personality characteristics that psychologists test for and study the genetics of are about 50 percent inheritable. Introversion, extroversion, it turns out that they're about 50 percent inheritable, which means that somehow sociopathy is physical, it's organic.

I am always impressed by the fact that even the tiniest amount of being listened to, the barest suggestion of the possibility of kind treatment, can bring such an immediate rush of emotion. I think this is because we are almost never really listened to. In my work as a psychologist, I am reminded every day of how infrequently we are heard, any of us, or our actions even marginally understood. And one of the ironies of my "listening profession" is its lesson that, in many ways, each of us ultimately remains a mystery to everyone else.

If courage is acting according to one's conscience despite pain or fear, then strength is the ability to keep conscience awake and in force despite the demands of authorities to do otherwise.

Sociopaths are not usually physically violent. A typical sociopath never kills anybody and doesn't look like Charles Manson - they look like you and me and everybody else. You're not looking for someone who's recognizably evil or scary-looking, but rather someone who looks normal. Another lynchpin is dishonesty. Lying for the sake of lying. Lying just to see whether you can trick people. And sometimes telling larger lies to get larger effects.

Sociopaths are often extremely charming. They are people who are better than you and me at charming people, at being charismatic. I've heard this more often than I can count: "He was the most charming man I ever met," or, "She was the sexiest woman I ever met," or, "The most interesting person I ever met . . ."