Marking Bodies: A History of Genetic Sex in the Twentieth Century

Abstract

This dissertation examines the history of genetic sex research between 1900 and 1960. During this period, geneticists offered a new account of sexual difference, asserting that chromosomes determined whether an individual became male or female. The project makes three central arguments. First, it demonstrates how geneticists constructed sexual difference as a "plastic dichotomy," a distinction that paradoxically suggested that the two sexes were discreet, and yet overlapping. Secondly, it illustrates how conceptions of genetic sex became more fixed or fluid as scientists, doctors, and social commentators struggled with one another to define a material, biological basis undergirding the difference of sex. For example, competing theories circulated about whether the chromosomes should serve as more reliable indicators of sex than hormones, gonads, or genitals. Finally, the project explores how descriptions of sexual difference intertwined with normative ideals about the proper roles that men and women should play in society.

At a time when social concerns about sexual difference and sexuality ran high, biologist Oscar Riddle, journalist Amram Scheinfeld, and physician Murray Barr made the study of sex determination relevant to questions about feminism, eugenics, and the treatment of homo-, trans-, and intersexuality. By focusing on these three, lesser-known figures, the project tells a history of genetics from the margins in order to investigate the challenges that geneticists had to overcome in order to make a genetic account of sex compelling. Analyzing from the margins, we can gain a novel perspective for understanding how genetic proponents and critics continuously refashioned the significance of the chromosomes in relation to sex, ultimately making sex more fixed, and genetics more authoritative.