The sexual development of children of gay and lesbian parents is interesting for both scientific and social reasons The present study is the largest to date to focus on the sexual orientation of adult sons of gay men. From advertisements in gay publications, 55 gay or bisexual men were recruited who reported on 82 sons at least 17 years of age . More than 90% of sons whose homosexual orientation could be rated were heterosexual. Furthermore, Gay and heterosexual sons did not differ on potentially relevant variables such as the length of time they had lived with their fathers. Results suggest that any environmental influence of gay fathers on their sons' sexual orientation is not large. An appreciable minority of both gay men and lesbians have children (Bell & Weinberg, 1978), and although difficult to document, it seems likely that increasing numbers of openly gay and lesbian people are forming families. Development of children of gay and lesbian parents has begun receiving the attention of researchers (e.g., Patterson, 1992) for both scientific and social reasons. A primary scientific question is whether children of gay and lesbian parents are especially likely to become gay or lesbian themselves, and if so, why. The primary social question, whether gay and lesbian parents are as desirable as heterosexual parents, has arisen most vividly in child custody cases. The scientific and social issues are closely related, because a primary focus of expert testimony in custody cases has been the impact of being reared by a gay or lesbian parent on children's sexual orientations (Falk, 1989; Harvard Law Review, 1989). Sexual Development of Children of Gay and Lesbian Parents Children of gay and lesbian parents might be expected to have elevated rates of homosexuality because they receive both environmental and genetic input from their parents. At least three environmental transmission routes are conceivable. The most obvious possibility is that children may acquire their sexual orientations in part by imitating their parents. By this model (discussed generally by, e.g., Sears, Rau, & Alpert, 1965). a child identifies with his same-sex parent and thereby adopts the kind of love object preferred by that parent. An immediate problem with this model is that most gay men and lesbians have heterosexual parents and thus develop opposite to the model's prediction. Psychoanalytic theorists (eg., Bieber, 1962) haw attempted to resolve this paradox by hypothesizing that, as children, homosexual individuals identified with their opposite-sex parents. In men, such atypical identification supposedly results from an unusually dose mother-son relationship coupled with a distant father-son relationship. In women, according to psychoanalytic theory, an especially antagonistic relationship with the mother impedes identification. Consistent with the theory, gay men tend to recall their fathers as having been emotionally distant and lesbians tend to report poorer