Freud's constitutional orientation led him to adopt the concept of bisexuality. This concept held that each individual was constitutionally endowed with both male and female psychosexual attributes that eventually sought instinctual gratification in terms of object choice. Freud postulated that in the child the sexual opposites for sexual behavior were at first activity as opposed to passivity, but without any comprehension by the child of sexual role. As the child discovered the difference between male and female genitals, he came to understand the biological significance of masculine and feminine. If the child's previous behavior had been active, his subsequent identification was with the masculine sexual role; if passive, with the feminine sexual role. Environmental influences acted through this innate predisposition that is, a person was born either active masculine or passive feminine and he responded to external factors on the basis of these inherent trends. If the predisposition to femininity was strong, fixation of the libido at a homosexual level became mandatory; no environmental influence was necessary. If the predisposition was weak, then strong environmental influence was required to achieve the same effect.

From clinical observation, Freud gradually formulated the classical mechanisms for the development of homosexuality. I have recapitulated the more important of these in the language of the libido theory:

(1) The simplest mechanism for homosexual fixation is also the one most likely to occur on a purely constitutional basis. The individual who resorts to this mechanism shows an excessive erotogenic interest in his own genital! during the autoerotic period. Later, when shifting from autoerotism to object love, he remains at a point of fixation between the two. s a res~lt his partner must have a genital similar to his own for him to feel any sexual attraction. In fantasy he then loves himself through his partner.

(2) A more complicated mechanism has its origin in castration anxiety. The patient, following the failure of his oedipal strivings toward his mother, regresses from object-love to narcissistic identification. He introjects the mother, identifies with her incorporated image, and thus magically becomes the object that he cannot possess. He then behaves toward others as previously he had wished his mother to behave toward him. He chooses homosexual love objects and gives them the love he desired from his mother. Although he acts as if he were his own mother, emotionally he is centered in the homosexual object and thus enjoys being loved by himself.

(3) In those cases in which there is an anal fixation of the libido, in addition to a homosexual fixation, the wish for sexual gratification from the mother becomes transformed into the wish to enjoy it in the same manner as she does, with the father as the love object. The patient carries out a narcissistic identification with the mother and then submits himself to a father substitute in a passive receptive manner.

(4) Another mechanism Freud called "retiring in favor of someone else." This referred to rivalry situations in which the competitive hatred was held in check by transformation into homosexual love. Most often this occurred in rivalry between brothers, occasionally in the rivalry of the son with his father.

These mechanisms all reflect the vicissitudes of the sexual instinct in its search for gratification. They are, of course, adaptational responses, but Freud referred their ultimate explanation internally to instinct rather than externally to social environment. The primary determinant lay in the varying degrees of the original homosexual endowment rather than in the specific life experiences that constituted social reality.