In psychoanalysis, a complex (2), closely linked with the Oedipus complex, focusing on fantasies of one's penis being cut off, evoked in a child by the discovery of the anatomical difference between the sexes. In a boy, it induces anxiety about being castrated and initiates the latency period; in a girl, it is experienced as a loss that she has suffered and initiates a desire for the paternal penis and attempts to deny or compensate for the loss. Sigmund Freud (1856–1939) introduced the concept in 1908 in an article ‘On the Sexual Theories of Children’ (Standard Edition, IX, pp. 209–26, at pp. 215–17) and developed it further in his famous case of Little Hans, ‘Analysis of a Phobia in a Five-Year-Old Boy’, first published in 1909 (Standard Edition, X, pp. 5–149). See also phallic stage.