I grew up in a violent home. My mother was an alcoholic and my father was institutionalized for mental health reasons. He killed himself approximately a year after his release, when I was about 2 years old.
My mother got a bunch of different boyfriends after that, all of whom were alcoholics as well and abusive in one way or another.
My mother was also abusive at times. She had anger issues and would sometimes hit us to the point where we didn't know if she was ever going to stop. She picked up my brother once when he was throwing a tantrum and literally threw him onto the bed, ordering him to stay there, warning him that if he didn't she would beat him. He was about 5 or 6 years old at the time. Another time my brother and I were stealing money from the motel my mother was managing and when she found out, I blamed it all on him. She literally beat the shit out of him over it. On another occasion she hit my sister with a baseball bat and on yet, another occasion she put a knife to my neck, but she only did that to see how I'd react. I found it amusing.
Fortunately, I was never an emotional kid, so not much bothered me.
I'd say my sociopathy is partly nature, but mostly nurture. What we experience in life has an affect on how we view the world and to some degree, it influences who we become as adults. When you grow up with violence, you see the world very differently from those who didn't. I see the world as a jungle full of predator and prey. If you're not the predator, you're the prey.
As for the nature part of my comment... Like me, my mother is not an emotional person either. Hardly anything affects her. These days she rarely even gets angry anymore. I don't think she's capable of love. She used to lie, cheat and steal when she was younger and she can be manipulative at times, or used to be anyway. I suspected she was a psychopath for the longest time, but I'm not sure anymore. She definitely has some psychopathic traits at least.
Anyway, that's my story and it's only a small portion of it. There's a LOT more I could tell you about my past, but it would be far too long.