While there's a big genetic component, the best way to create a sociopath is horrific, continuous child abuse at a young age.
And there's also a pattern of a lot of serial killers having had a severe head injury when they were young, as well.
Exactly right, to the best of my knowledge. Look at Hitler and the way his father Alois treated him and look at what he became.
Head injuries ? Well, there was the Chris Benoit incident....