What is most fascinating to me is the fact that posts like the parent will delve into the game theoretic motivations of psychopathy as if the psychopath were some wholly unique flavor of creature operating under behavioral algorithms never before seen, when the truth is that your neurotypical, salt of the Earth Johnny Lunchpail is doing the same thing, except on a different timescale, and with the utility functions ingrained into heuristics like 'empathy' and 'compassion' and the like.

Unless you believe that your motivational orientation is made of some magical pixie dust handed down by the Holy Ghost, you should keep in mind that your instincts, your sense of morality and right and wrong and all those gut feelings are engendered by a truly massive utility computation; your feelings of selflessness as you drop the coins in the bell ringer's jar, your protectiveness toward your children, your lesser protectiveness toward your more distant kinship relations, all of it is equivalently cold-blooded. It's just dispersed enough that you don't see it for what it is.

So when you stop talking to your friend because he's annoying, or you don't give money to that homeless guy because you've already gave enough money, and maybe he's a drunk; and you buy a nice present for your nephew but not your coworker's kid, and you think it's best that your grandmother died because she was suffering so terribly, you're a psycopath, too. There's just a lot of epiphenomenal stuff larded on top of it.