Norman Bates

Portrayed by Anthony Perkins (Psycho, 1960)

Fictional character created by writer Robert Bloch as the central character in his novel Psycho. The character is based on real-life serial killer Ed Gein.
The characterization of Bates in the novel and the movie differ in some key areas. In the novel, Bates is in his mid-to-late 40s, short, overweight, homely, and more overtly unstable. In the movie, he is in his early-to-mid-20s, tall, slender, and handsome. Reportedly, when working on the film, Hitchcock decided that he wanted audiences to be able to sympathize with Bates and genuinely like the character, so he made him more of a "boy next door." In the novel, Norman becomes Mother after getting drunk and passing out; in the movie, he consumes no alcohol before switching personalities.

Both the novel and Alfred Hitchcock's 1960 film adaptation explain that Bates suffers severe emotional abuse as a child at the hands of his mother, Norma, who preaches to him that women and sex are evil. The two of them live alone together in an unhealthy state of emotional dependence after the death of Bates's father. When Bates is a teenager, his mother takes a lover, thereby making him insanely jealous. Bates then murders both of them with strychnine and preserves his mother's corpse. Bates develops dissociative identity disorder, assuming his mother's personality, repressing her death as a way to escape the guilt of murdering her. He inherits his mother's house, where he keeps her corpse, and the family motel in Fairvale, California.

Bloch sums up Bates' multiple personalities in his stylistic form of puns: As "Norman" Bates, the little boy, he is dominated by his mother, and has to do whatever she tells him. As "Norma" Bates, he dresses in her clothes, mimics her voice, and kills anyone who threatens to come between her and her "Norman," especially attractive young women. As "Normal" Bates, he is a (barely) functioning adult who runs the business of the motel and keeps peace between the other two personalities.

Norman is finally arrested after he murders a young woman named Mary Crane (called Marion Crane in the film) and Milton Arbogast, a private investigator sent to look for her. Bates is declared insane and sent to an institution, where the "mother" personality completely takes hold; he completely becomes his mother.

Bates dies in Bloch's 1982 sequel to his novel.

Taken from Wikipedia