Answer: SCHIZOID Personality disorder is most appropriate for Joe.
Explanation: Schizoid personality disorder in psychiatry is a class of mental disorders characterized by social withdrawal, lack of emotion, very few or no close friends, excessive preoccupation with fantasy and insensitivity to prevailing social norms and conventions.
This definition perfectly describes Joe. Living alone, no friends, doesn't want to make new friends, doing the minimum. Etc.