In his theory of the "Oedipus complex," Freud argued that the mother-son relationship is a critical factor in the development of the child's psyche. According to Freud, the child experiences a desire for the opposite-sex parent (in this case, the mother) and feels rivalry with the same-sex parent (in this case, the father). This complex is resolved when the child identifies with the father and repressed the desire for the mother.