How does someone come to be sociopathic or psychopathic?

Today while watching the "Good or Evil" video I really contested their method and way of determining whether the child was morally good or bad because it related to determining whether someone was capable of psychopathy or sociopathy; this made me think if we can even determine sociopathy or psychopathy at such a young age. In the experiment the child had to choose between just two dogs to decide whether they were "good" or "bad". This is a ridiculous way to determine because the margin of error is so high. The baby has a 50/50 chance of being categorized as good or bad. If feel adults who are psychopathic or sociopathic are effected by nurture instead of nature too. As far as we can tell these kind of people have had traumatic experiences or upsets that have influenced their motives and the way they think. Who knows what other factors play a role into the development of a sociopath or psychopath too? It is very logical to assume many traits and characteristics inherited from their mother and father can play a role into this too. But this is a more vague area of determining this character. Many traits are capable of influencing each category and when they mix with nurture we do not know how they will affect childhood development. In the end I feel it comes down to nurture. There are other factors that contend or agree with the nurture like if someone doesn't really connect with people and feel their emotions. However, if this person is raised right and understand the rules and laws of society he can be  a perfectly normal human being but without emotional attachments.