Dexter - Psychopathic or Sociopathic?

For the past week, we have been studying psychopaths and sociopaths and the traits associated with each condition.  In our discussion, we also explored examples of each in TV shows, movies, etc.  Instantly, the example that popped into my mind and that I shared with the class was "Dexter", the Showtime original that appeared on Netflix.  Unsurprisingly, the show also came up as an example on one of the websites, but the website classified the main character, Dexter, as a psychopath when I believed that from examples in the show that he is clearly a sociopath.  For those who don't know, Dexter is a seemingly normal person, who has urges to kill.  To channel these urges he thoroughly vets people who have commited terrible crimes, and only kills those who are menaces to society.  Before I get into the details, let's back up a step, and I'll share the definitions of psychopath and sociopath that I will base my judgments on.  According to the infographic, the main differences are in the origin of the condition: a psychopath seems to be something a person is born with and inherited through genes, while a sociopath is the result of childhood trauma or a harsh childhood environment.  Other differences include that a psychopath has controlled behavior, while a sociopath is impulsive and erratic.  Looking deeper into these definitions, I can see why the website might have classified Dexter as a psychopath.  He clearly has controlled actions and is a highly manipulative and careful person.  He plans his murders for months sometimes, making sure that nothing can possibly go wrong.  He has a successful career and even a girlfriend.  He fits right into society, and no one would seem to suspect otherwise.  But the key defining trait of a psychopath is missing here.  Yes, on first glance of the show, he is seemingly a psychopath.  But we learn that it wasn't always this way.  Dexter witnessed his mother being brutally murdered at the age of about 3, and his foster father, a police officer, found him sitting in a pool of his mother's blood where she had been murdered in a shipping container.  So according to this fact, he is clearly a sociopath.  Also, we can't assume psychopathy because we know little about his biological parents and the possibility of inheritance from them.  Another trait of sociopathy that Dexter fits is that he knows the rights and wrongs of society; he just follows his own moral code.  He references it throughout the show, naming it after his father who taught it to him, Harry's code.  In the first episode, there is a flashback to his childhood where he kills the neighbor's dog and defends himself by saying that it was annoying and keeping his sick mother from sleeping.  His father then asks him if he would ever kill a human, and he tells his father that the only reason he hadn't is because he knew his parents wouldn't like it.  In my opinion, Dexter is clearly a sociopath, but I can see why he would be classified as a psychopath.  What do others think based on this information?  If you have any questions ask me in the comments.