Knowing what causes differentiation in human skin pigmentation, fascinating though that is, does not furnish a satisfactory explanation for the phenomenon of racism. Similarly, the biological explanation for why one person is right-handed whilst another is left-handed, is of less interest than why, even recently, being left-handed was considered such a stigma (…).Do we need to know what ‘causes’ homosexuality or heterosexuality? (…)Would the discovery of a genetic basis to sexual attraction finally undermine discrimination against non-heterosexual people by establishing that variations of sexual orientation are all equally rooted in nature? Or would it furnish powerful homophobic forces with a new weapon in their drive to undermine and remove the rights of non-heterosexual people, perhaps even the right to life itself? The infamous remarks of a senior religious leader (a former Chief Rabbi) in the UK a few years ago that, if a gay gene could be discovered, he would consider it morally acceptable to test pregnant women and offer them the option of aborting any foetus likely to develop into a non-heterosexual person - homophobic extermination in the womb - indicate that the huge moral and cultural debates around sexuality and human identity will not be solved either way by the biological sciences alone