*Sodomy Ensues*

[Nintendarse]

I agree with Weltall that the case for genetics is patchy and unproven. Because there are no clear scientific causes of homosexuality, it would be premature to put a stake in any of the hypotheses. But, in the same manner, the case for sexual orientation as a choice seems just as dubious. Again, from the amicus brief:

Current professional understanding is that the core feelings and attractions that form the basis for adult sexual orientation typically emerge by early adolescence. [36] For some people, adult homosexual orientation is predictable by early childhood. [37] Developmental precursors of adult homosexual orientation, however, have not been consistently identified for the population as a whole. [38]

A number of researchers have found familial patterns and biological correlates of adult homosexual orientation, suggesting that genetic, congenital, or anatomical factors may contribute to its development.For example, recent studies have indicated a linkage between certain aspects of DNA and sexual orientation.[39] Studies of identical twins have found that "heritabilities were substantial under a wide range of assumptions." [40] Another study, as yet unreplicated, reported differences between heterosexual and gay men in the volume of a cell group in the anterior hypothalamus, a brain structure that is involved in sexual behavior.[41] A study published earlier this year suggests that women who had been exposed to certain prenatal estrogens are more likely to be lesbian or bisexual.[42] Another study has suggested an "interactionist" model, under which "genetic factors can be conceptualized as indirectly influencing the development of sexual orientation." [43]

The available studies of gay experience indicate that same-sex attractions generally emerge by early or mid-adolescence. [44] "By the time boys and girls reach adolescence, their sexual preference is likely to be already determined, even though they may not yet have become sexually very active."[45] The scientific literature thus strongly indicates that sexual orientation is far from being a voluntary choice.[46]