Gender taxonomy

The gender taxonomy is a classification of the range of different levels at which humans vary in sexual characteristics. It is mainly used by medical specialists working in the area of sex research. "A review of cross-gender taxonomies shows that previous observers have identified and labeled a homosexual type far more consistently than any other category of male gender dysphoric."

Ray Blanchard, "The classification and labeling of nonhomosexual gender dysphorias", Archives of Sexual Behavior 18/4 (1989): 315–334. John Money and Milton Diamond are probably the best known researchers in this field. Money earned his PhD for research into human hermaphroditism and pseudohermaphroditism, now known as intersex conditions. The taxonomy starts at the simplest, biological level and traces differentiations expressed at the increasingly complicated levels produced over the course of the human life cycle.