Final answer:
Boys' fear of castration in psychoanalytic theory is most closely associated with the Oedipus complex during the phallic stage of Freud's psychosexual development theory.
Step-by-step explanation:
According to psychoanalytic theory, boys' fear of castration is most closely associated with the Oedipus complex. The Oedipus complex is a concept in Freud's psychosexual development theory during the phallic stage (3-6 years). During this stage, a boy experiences desire for his mother and sees his father as a rival, leading to castration anxiety. He fears that his father will punish his desires, a fear that is resolved when the boy begins to identify with his father.
This concept is part of a larger framework where each psychosexual stage of development focuses pleasure-seeking urges of the id on a different erogenous zone. The stages include oral, phallic, latency, and genital. Personalities in adulthood may be affected by a person's experiences during these stages.