Endocrinologists and the conceptualization of sex, 1920-1940.

Abstract

The study of sex differences in modern biomedical sciences has a tradition that dates only from the eighteenth century. Earlier scientists were not very interested in differences between the sexes. They assumed that there existed one basic structure for the human body; men and women were thought to differ only in the anatomy of their genitalia. It was in the course of the eighteenth century that the study of sex became a priority in scientific research. After 1750, publications appeared suggesting that the description of the female body had been ignored by leading physiologists, and scientists were encouraged to study sex differences. Following these suggestions, scientists took up the study of skeletons, blood, and other anatomical and physiological features, comparing male and female organisms.' In the twentieth century new ways of studying sex were introduced through the emergence of new fields of science, including the important field of endocrinology. Endocrinologists defined sex on the basis of a new concept: sex hormones. The early development of sex endocrinology was directed by the underlying assumption of a dualistic concept of sex, according to which female sex hormones could be found only in the female organism, and male sex hormones were believed to be present only in males. However, starting in the 1 920s the idea of maleness and femaleness as clearly defined endocrinal states became a topic of debate in the scientific community. Observations on the origin and function of sex hormones contradicted the original concept of sexual specificity, and by 1940 it had been transformed into a concept of relative sexual specificity. Maleness and femaleness were