I remember reading a long account by the father of a psychopath. If I recall correctly, the kid had at least one other sibling who turned out normal, there was no abuse, quality education, lots of love and affirmation. And the kid still turned out violently antisocial, including against his own parents.

At the end of it he said he wished his child had never been born, despite hating himself for feeling that way. It chilled me to the bone.