Final answer:
The Psychoanalytical theory, developed by Sigmund Freud, emphasizes the role of unconscious sexuality in the structure of personality, characterized by the balancing of the id, ego, and superego through various psychosexual stages.
Step-by-step explanation:
The theory that emphasizes the structure of the personality on the unconscious nature of sexuality is the Psychoanalytical theory developed by Sigmund Freud. Freud's theory suggests that the unconscious drives, primarily those related to sex and aggression, heavily influence our personality. Freud proposed three components to personality: the id, ego, and superego, which must balance the primal urges with the moral ideals. He also theorized that personality develops through a series of psychosexual stages, which focus on different erogenous zones during childhood development. This process is believed to leave a lasting impact on the individual's personality and behavior.
While Freud's theory was highly influential, later psychologists known as neo-Freudians began to modify his ideas, reducing the emphasis on sexuality and incorporating more elements of social and cultural determinants of personality development.