Scientists uncover route for finding out what makes individuals nice or nasty
A scientist has helped develop an innovative mathematical model for exploring why some individuals evolve to be genetically programmed to be nice, while others stay nasty. Ref. Source 3x.
I don't know if its genetic or not but there are some people that no matter what touches them they remain the way they are. I see it with criminals. You give them chances, they know what its like in prison and yet they commit the same nasty acts again and again like they're wired to only be that way.