Nowadays, medical spheres made little to no distinction between psychopathy and sociopathy, though judging by the general feeling about the joint classification as antisocial personality disorder, that would soon change. Of that, Sherlock approved. He could hardly argue the difference to idiots like Anderson if they realised that a doctor wouldn't differentiate.
John had called him on the difference. Of course, Sherlock knew that John had been further researching sociopathy; it had long since become habit to check the browsing history of any computer he touched.
"Check a dictionary," he had replied.
"I did. Both terms are now considered antiquated."
"I consider Anderson an idiot but Sergeant Donovan disagrees."
"Idiocy isn't a personality disorder."
"Idiocy is an antiquated medical term, too. One from which Anderson is clearly suffering."
And that had been the end of that conversation.
In fact, there were some dictionaries that still gave differing definitions. Psychopath (n.) a person with any personality disorder. Sociopath (n.) a person with a personality disorder pertaining to social problems.
Which meant Sherlock was both a psychopath and a sociopath.
"You're neither," John said, after reading the entries put in front of him. "A psychopath is vicious. And a sociopath doesn't have friends."
Sherlock turned to face his flatmate. His friend?
"You're not Moriarty, Sherlock. That's something you need to believe."