I think it's human nature, too. I had my "wanting to hurt other people" impulse cut off or dissociated, believe it or not, so the therapy for dissociation is to try to get those things back! Because they're there, whether you are aware or act on them or not, and it messes you up to have part of yourself cut off.

So, yeah, now I know the "If you hurt me I'll hurt you back" impulse. It happens AFTER I feel a rage response and want the other people to care about that! And if they don't, if they can't make things right with me, then the "I want to hurt you impulse" shows up. Don't have to act on it. But, yeah, if something does hurt them . . .just some primitive reaction to feel satisfaction in the "I want to hurt you" impulse even if I didn't act on it.

Probably starts because of the jealousy? Not something you have any control over (much) either? Main thing for that -- my guess -- would be a stronger sense of self, loving yourself, self-esteem, etc. Which is something lacking(or else overblown) in a bunch of PD's I would guess. Certainly true for me (PDNOS)!