I’ve had a close encounter with a psychopath over the last four years, and as a result have done a geat deal of research trying to understand and predict his behavior. He does not know what it is to feel badly about something he’s done simply because it was wrong, or hurt someone else. (remorse) He can, however, deeply regret an action if it causes him inconvenience or pain. He does not internally feel any negative result from simply realizing that he has done wrong. He does, however, have a pathological fear of getting caught doing wrong, and he experiences anxiety and fear in that regard. He fears punishment.
I think empathy is a basic sense rather than an emotion. There are specific “mirror neurons” ( http://en.wikipedia.org/wiki/Mirror_neuron ) which respond to the actions of others autonomically. This is the mechanism, for instance, which causes us to yawn when we see someone else do so. (A great way to spot psychopaths, incidentally, because they don’t.) We can’t choose whether to be touched by another’s suffering any more than we can choose whether to smell something. We may be able to avoid wrinkling up our nose at the smell, or allowing ourselves to dwell on other people’s problems, but we can’t choose simply to not perceive it. The psychopath can not perceive it; and explaining it to him is as difficult as explaining “blue” to a man blind from birth.
So there’s the basic perceptive ability, and then there’s the turn of character. I think that there is an empathy/narcissism spectrum which has the codependent at one end and the sociopath at the other.
The next step toward the Hollywood horror version or the ASPD is, IMHO nurture. It’s important to note that psychopathy is not necessarily co-morbid with enjoyment of cruelty, (sadism) or sexual dysfunction (pedophilia, etc.). These things are the result of ill treatment in childhood. When all these things combine together, we get monsters.
Here’s a fascinating article about a scientist who discovered that he clearly had the brain scan of a psychopath. He also, however, had a loving, gentle upbringing, and is by all reports a caring and gentle man. He is a good man because it’s what he’s been taught, and what he wants to be, but he probably does not receive empathetic information in the way the rest of us do. http://www.npr.org/templates/story/story.php?storyId=127888976
So, I said all that so I could say this: the numbers like 1 in 4 are counterintuitive, because they do not necessarily represent the number of serial killers or child abusers in the human population. Rather, they represent the numbers of people who operate without the basic mirror neurons firing. They are only potential serial killers.
Which leads us to the simple solution: We as a society will suffer the horrors to exactly the extent that we allow children to be abused. If we want to clear out the supermax prisons, we need only make a committment to protecting and treating the abused children in our midst.
Good luck getting the politicians to vote for the funds though.