When the id is expressed, it "seeks immediate satisfaction of instinctual urges and drive"(Hockenbury 364). Bates' id, as the "Hyde" in the film "Psycho", is characterized by an Oedipal complex, guilt, and the expression of repressed sexual desire. .
Bates has had an Oedipal complex since he was a young boy, which is a factor in why he is sometimes a "Hyde". An Oedipal complex is a mental condition in which a boy has a subconscious sexual desire for his mother. The earliest indication of his Oedipal complex is when Bates kills his mother after catching her in bed with another man. His act of matricide and his subsequent refusal to accept it are both fueled by his Oedipal complex. Bates' jealousy of his mother is shown by his assumption of her reciprocal jealousy of him, as well as his unconscious belief that she does not want him to become involved with other women. Therefore, the "mother" side of Bates kills whomever he takes an interest in. When a beautiful woman, Marion Crane, visits the Bates' hotel, the mother side of him quickly emerges due to the fact that he is attracted to Crane. He has a dialogue with his own version of his "mother" in which she jealously refuses to permit Crane to eat in their house. Later, he secretly watches her change her clothes. This arouses him more, which prompts the mother side of him to kill Crane. This act is a strong demonstration of the Oedipal conflict inside the mind of Bates in relation to his split personality. His rational, moral half is subdued and the unconscious side of Bates is given free reign: He becomes "Hyde".
Guilt is another reason Bates becomes "Hyde". Like an Oedipal complex, it deepens the rift between the two halves of his personality and makes his "Hyde" more apparent. When Bates kills his mother, he cannot accept the guilt of matricide. To avoid this guilt, he preserves his mother's body and convinces himself that she is still alive by dressing up as her, even donning a wig for the part.