Freud's theory that individuals pass through a series of five psychosexual stages (oral, anal, phallic, latency, and genital) in which pleasure-seeking energies focus on different erogenous zones. Unresolved conflicts at any stage can lead to fixation and psychological issues later in life.
Freud's psychosexual stages fall under the psychoanalytic perspective, emphasizing unconscious drives and the influence of early childhood experiences on personality development.
Freud's theory is largely based on clinical observations rather than empirical research. Subsequent studies have challenged its scientific validity due to the lack of direct supporting evidence and testability.