I believe psychopathy is primarily a genetic disorder. If someone has autism or mental retardation, undoubtedly early environment has a role to play in social development and functional outcomes, but the condition will limit the extent the environment can attenuate the condition. The same is true for psychopathy, imo.
Unlike the autism or mental retardation spectrums, psychopathy is a high-functioning disorder, it's difficult to detect because it only effects the deepest parts of the individual's identity. They are able to function socially and intellectually at a very high level, the illness sits deeply hidden in the psychopath's inmost interpretation of their social interactions. That interpretation consists of a profound isolation, a complete inability to be touched by others emotions, a complete lack of conscience because no true connection with others is possible.
Look at Scott Peterson, his mother doted on him, he was the golden child, provided plenty of attention, yet he was a full blown psychopath just the same.
There is a researcher who was doing brain scans to try to identify psychopaths, and he was able to see profound indications in the scans, he was shocked to see his own brain scan showed him to be a psychopath, he was not a criminal, antisocial, or anything. He said he was raised in an extremely loving, socially nourishing, secure environment. What that did was give no ground for antisocial behaviors to develop, yet the condition still showed up via the brain scan. Essentially, his exceptionally positive early environment had made the social consequences of his psychopathy dormant.