Though the outcome of the "gay gene" debate is uncertain, the very fact of the debate is evidence of great change: The prevailing scientific view of the fundamental nature of homosexuality has undergone a signficant evolution in the last several decades. Where once the scientific and medical establishment maintained an unqualified belief that homosexuality was a form of psychological deviance, today a solid majority of psychiatrists and psychologists themselves believe in biological theories (genes, brain, prenatal chemistry) over environmental or psychological theories. More scientists are getting involved in this type of genetic research, although funding has not been keeping pace with the intensity of interest.

Even at the early stages of an emerging scientific consensus around biological theories of homosexuality, it is not possible to keep politics out of the debate. In his most recent book, Simon LeVay, who has been at the center of it all--and who is gay himself--wrote of a "worrisome question" that he faces quite often: "Are the positions taken by researchers merely the expression of their own personal attitudes and prejudices--whether pro-or anti-gay--that have been dressed up in academic language. . . ?" To espouse environmental or psychodynamic theories in recent years has been to invite charges of anti-gay bias or homophobia, he notes; and biological theories seem "pro-gay." But even these political lines can be blurred: Some have worried that the "gay gene," though often seen as tied to "pro gay" politics, could become a tool of a repressive, eugenically inclined majority looking to breed out undesirable same-sex behavior. The debate continues.