I read that book years ago because some dude was driving me “nuts”. Book set me straight.
I don’t agree that the sociopath is highly intelligent. He can have a low IQ and use his highly respected family name for credibility. That family name lets him get away with doing/saying stuff that us regular folks wouldn’t be able to.
I would say that sociopaths would have at least a slightly above average IQ. If they lacked intelligence they would not be able to function since it requires a constant juggling of lies and an ability to play roles very well.
When you come across a sociopath of gifted IQ or better you have a serious problem. Adolf Hitler was one. I could name a few politicians in America too but everyone on this site already knows who they are.