These people do not think like the rest of us. In some ways, they are surprisingly and dangerously effective. They can lie their heads off and never give a behavioral clue that they’re lying. The only way to know they’re lying is to “go to the tape”.

Their sincerity fools legions. But part of the reason why they can lie so unblushingly is that they’re good at forgetting inconvenient past details. If you literally do not remember your transgressions or unwanted promises, you cannot be tripped up by your own misgivings or guilty memory during later interrogation.

So although any idiot would have realized that anyone with Charles’s computer skills would have kept a permanent archive, this fellow probably never imagined anything of the sort. May well have re-remembered his past so effectively that he now “believes” that he really never said it. And he’ll be in a fuming rage that he’s been libeled, and he’ll be scheming how to “get even”. Lawyers he talks to, with a Machiavellian streak of their own, but not so deep as to push them around the bend, will browse around a bit and discover that they’re much too busy to take his case, but gee, they sure would have loved to help out if only it had been possible. Honest! Sincerely!

Have you ever met a person who left you wondering, “How could someone be so twisted? So evil?” Prompted by clues in her sister’s diary after her mysterious death, author Barbara Oakley takes the reader inside the head of the kinds of malevolent people you know, perhaps all too well, but could never understand.

Starting with psychology as a frame of reference, Oakley uses cutting-edge images of the working brain to provide startling support for the idea that “evil” people act the way they do mainly as the result of a dysfunction. In fact, some deceitful, manipulative, and even sadistic behavior appears to be programmed genetically—suggesting that some people really are born to be bad. But there are unexpected fringe benefits to “evil genes.” We may not like them—but we literally can’t live without them.

We can live without the evildoers, but we cannot live without the genes that, in excess and in combination with developmental accidents, chance, fate, and free will, code up a brain that’s biased toward that sort of thing. The perfectly good-gene person is a naif, a chump, a sucker. Pig, from Pearls before Swine the comic strip.