social, rather than a product of one or the other. It is in the period after infancy, when the child begins to develop language skills, until adulthood that the child begins to undergo very different processes. These processes are extremely culture-bound. It is through these processes that the child begins to organize how s/he will deal with the world. There are two experiences that dominant theseyears. The first is the naming of the behaviors, and adult reactions to them, specifically the sexual. The second is the continued building of gender identities based on decisions made on the maleness or femaleness of the child by adults (parents, doctors, etc.). A wealth of studies on families and twins show heredity accounting for between 30 and 70 percent of the variationof the hypothalamus, a part of the brain that has been shown to differ between homosexual and heterosexual men. He also looked for a comparable X-linked marker for sexual orientation in lesbians, but had little luck. Female homosexuality does run in families, but there's no clear indication that it is genetic. He suspects that women's sexual preferences may be less genetically programmed than men's. It appears that sexual preference is partly social and also genuinely biological (http1). Many studies have also looked at the sexual preference in animals (http2). Several domestic and wild animals engage in sexual activity with members of both the same and the opposite sex; a smaller number have eyes only for their own sex. Some of these homosexual activities appear to boost reproduction. In