Thinking about psychopathy leads us very quickly to a single fundamental question: Why are some people like this?
Unfortunately, the forces that produce a psychopath are still obscure, an admission those looking for clear answers will find unsatisfying. Nevertheless, there are several rudimentary theories about the cause of psychopathy worth considering. At one end of the spectrum are theories that view psychopathy as largely the product of genetic or biological factors (nature), whereas theories at the other end posit that psychopathy results entirely from a faulty early social environment (nurture).
The position that I favor is that psychopathy emerges from a complex—and poorly understood—interplay between biological factors and social forces. It is based on evidence that genetic factors contribute to the biological bases of brain function and to basic personality structure, which in turn influence the way an individual responds to, and interacts with, life experiences and the social environment. In effect, the core elements needed for the development of psychopathy—including a profound inability to experience empathy and the complete range of emotions, including fear—are in part provided by nature and possibly by some unknown biological influences on the developing fetus and neonate. As a result, the capacity for developing internal controls and conscience and for making emotional "connections" with others is greatly reduced.
(This article from Psychology Today was published in 1994 and is an excerpt from a book, by Robert Hare, called Without Conscience:The Disturbing World of the Psychopaths Among Us )
The one disorder I know best is called reactive attachment disorder, which I wrote about in Love and Economics:why the Laissez-Faire Family Doesn't Work. That disorder is almost certainly environmentally driven, as it is found among children who have spent substantial time in orphanages or in foster care, or with a profoundly negligent adult, such as a drug addict. I have come to believe that this environmentally triggered condition, does have a physiological component. The development of the limbic brain in infants is stimulated by being in relationship with a loving care-giver, usually, but not necessarily, the mother. When a baby is born, he has to develop a sense of self and of the difference between himself and other people. To do this, the baby needs to look for another person, and have that person look back. This activity actually stimulates the development of the part of the brain that governs the ability to be social and have empathy for other people. Hence, if the baby has no one to look at, as is often the situation of orphanage children, their brains do not develop properly. They may have been born with every capacity for normal social development, but had it stunted by their environment. I learned this stuff from a great book called, A General Theory of Love. After I learned this, I included it in my second book, Smart Sex: Finding Life-long Love in a Hook-up World.
Having said this, I hasten to add: just because some sociopaths are made, does not preclude the possibility that some sociopaths are born. I think born are quite possible. We need an explanatory strategy that can account for both possiblities.
I also hasten to add: the experience that many of my readers are reporting is not really about sociopathology, but about other mental illnesses that have different origins, symptoms and treatments. That is why I caution against painting with too broad a brush.