I am feeling toxic/sadistic inside, but for people i am very nice, especially for ppl that matter to me. I dont see a need to manipulate. I think some ppl just are born like that. They dont feel an emotional attachment, have little empathy etc.
But still you can be good for people, try to put a some effort to this.

BTW why u manipulate ppl, what you trying to get out of them ? Just curious