Really interesting comments on psychopathy. Welcome new members!
I think there are two schools of thought on the nature/nurture debate about whether psychopaths are born or created through their environment. I believe there has actually been some research done in the last few years that actually shows that psychopaths lack a basic hardwiring/neural activity necessary for empathy, etc. So there is research been done on both sides of the debate.
From my psych studies and from experience, I strongly believe there is a genetic predisposition to psychopathy. Of course life experience can strongly shape a person's choices, but I do believe there are people in this world who just don't possess what is needed to feel the emotions most of us feel. They perceive the world in a different way, not just because of abuse, upbringing etc. I think it runs a lot deeper than that.
I think there is much interest in studying children/teenagers in relation to psychopathy, but this is an ethical mindfield. For instance, if a child is found to have psychopathic tendencies, and is likely to harm someone in the future, should they be removed from society or should they be given the benefit of the doubt (even though treatment is usually unsuccessful in severe cases).
) followed by lack of conscience, remorse or guilt for hurtful actions to others at a later stage. There may be an intellectual understanding of appropriate social behavior but no emotional response to the actions of others. 
