I see myself as a "truth fanatic," as someone who is compelled to commit the truth. Whistle blowers have been described as truth fanatics.
Liars and truth fanatics were the subject of speculation by the early group of psychoanalysts who surrounded Freud. The psychological motivations of liars and truth fanatics were expounded by Otto Rank, a follower of Freud's.
The retired Washington, DC psychiatrist/psychoanalyst E. James Lieberman, M.D. addresses these issues in his biography Acts of Will: The Life and Work of Otto Rank.