Amative orientation: the hormonal hypothesis examined.

The hypothesis that human male and female amative orientation, arousal and courtship are sex-hormone dependent had as its precursor John Hunter's recorded but unpublished 18th century experiments of cross-sexed gonadal transplants in chicks. The hypothesis gained momentum in the 20th century after the discovery and eventual marketing of the sex hormones, and after the experimental demonstration by William C. Young that, in guinea-pigs, cross-sexed hormone administered prenatally influenced their subsequent male/female courtship and mating behavior. Comparatively and in review, human clinical syndromes of hypermasculinization and hypomasculinization do not disconfirm the hormonal hypothesis, but they do not adequately confirm it, either. They are compatible with the idea of a cofactor that governs whether amative orientation in practice, ideation and imagery is homosexual, heterosexual or bisexual.