For more info read Sociopath Next Door...its a great book and will give you an idea about some factors that could cause people to become sociopaths. Very very good book. I have a psych degree and a step brother who I fully believe is a sociopath. And according to the book a common denominator is the relationship the person has with their mother. But that book is the best one I have found to help explain it
If you want more info I can find my book and answer questions