In my experience, sociopathy exists on a spectrum of severity, from the death row inmate to the ruthless venture capitalist to the calculating cheerleader mom. Consider, as an example, someone with Down syndrome. I have two relatives that have Down’s—one blood and the other adopted. The blood relative does sort of look like the rest of his family, his siblings, and his parents, but he also looks unmistakably like his adoptive sister who also has Down syndrome. In fact, most people would probably say he looks more like his adoptive sister than his blood siblings—unless the observer was intentionally try*ing to look past some of the more obvious Down’s markers, such as the distinctive broad, flat face, creased eyelid, short stature, and so on.
Down’s is an interesting condition. Throw an extra chromosome in there, and it affects the way seemingly every other gene is expressed. It’s almost as if you take the individual’s raw genetic material and put a very distinctive mask over it.
I think that sociopathy is something like this. My personality resembles my siblings’ quite a bit. And it resembles the personalities of many people around me, my colleagues and friends, people whom I have chosen to surround myself with due to our mutual or complementary views of the world. But my personality also resembles those of other sociopaths a great deal, sometimes in ways more conspicuous because of our relative rarity in the general populace. It’s amazing to me how much of my habits of mind and proclivities of action I can share in common with strangers—with people who are of different genders, ethnicities, races, nationalities, backgrounds, ages. But I am not just like every other sociopath. From what I have seen of us we are all very different. But there is no mistaking a certain family resemblance.