Inspired by the ability of hormones to regulate metabolism, some medical researchers tried to realize the dream of human “rejuvenation” in the early 20th century. In 1920, Eugen Steinach (1861–1944) claimed to have found a scientific way to rejuvenate human bodies in a procedure he dubbed “the Steinach Operation.” Although highly controversial, the operation continued to be performed in Europe and America in the 1920s and 30s. However, its reception in Japan was different. When first introduced to Japan in 1921 by Sakaki Yasusaburō, it was immediately attacked by critics. It almost totally faded from the public eye after 1925 when Sakaki was ostracized by the academic medical community. Why did the rejuvenation method fail so quickly in Japan? Is it because this method was quackery or “pseudo-science,” or because rejuvenation was not attractive to Japanese people at all? This paper argues that the failure of the Steinach operation resulted directly from Sakaki’s defeat in the factional struggle within the medical community, while the operation’s scientific unfeasibility played a secondary role. The failure was further consolidated by the fact that the operation was not supported by or merged with other rejuvenation methods belonging to the non-Western yōjō/yangsheng tradition. This case study shows how the medical community in Japan in the 1920s evaluated the “effectiveness” of a new technology from the West and how this evaluation was strongly shaped by the power structure of the professional community. It also explores the interaction between Western and non-Western medical traditions.

In the aftermath of the New Culture Movement (1915–1919), Western-trained biologists in China helped establish a popular understanding of sex dimorphism that construed bodily morphology and function of the two sexes as opposite, complementary, and fundamentally different. Starting in the mid-1920s, urban Chinese intelligentsia began to construct a more fluid definition of humanity. They argued that at base, all humans are equal. They no longer drew on the limited language of anatomy to talk about two different but equal sexes. Rather, they started to think of men and women as simply two versions of a universal human body. They appropriated from Western endocrinologists the theory of universal bisexuality, which posits that everyone is partly male and partly female. This paper shows that a vibrant discourse about “sex change” existed in the mass circulation press of Republican China (from the 1920s through the 1940s). It traces how Chinese sexologists entertained the possibility of sex transformation based on a new hormonal vision of universal bisexuality and famous animal sex reversal experiments in Europe; it demonstrates how indigenous Chinese frameworks for understanding reproductive anomalies (hermaphrodites, eunuchs, etc.) provided an epistemological point of reference for communicating new and foreign ideas about sex; it assesses the impact of a highly sensationalized case of “female-to-male” transformation in mid-1930s Shanghai on people’s awareness of the possibility of human sex change; and it analyzes the culminating effects of these epistemological reorientations in a science fiction short story called “Sex Change” (1940) by the pedagogical writer Gu Junzheng.

The concept of hormone-dependent cancers, or cancers that are sustained by particular hormones, developed slowly during the period from about 1940–1990. I chart how the development of the notion of hormone-dependent cancers initially relied upon assumptions that cast androgens and estrogens, prostate cancer and breast cancer, as opposite ends of a gendered hormonal binary. Starting in the 1940s, cancer researchers began to argue that “male sex hormones” (androgens) exacerbated prostate cancer and that “female sex hormones” (estrogens) ameliorated it. Within about a decade, cancer researchers suggested that the opposite might be true for breast cancer. By the 1980s, estrogens had come to dominate discussions of breast cancer's progression, diagnosis, and treatment. While historians of breast cancer and estrogen have discussed concerns surrounding estrogen exposures (debates about the safety of oral hormonal contraceptive pills, for example), they have not examined in detail the processes by which estrogen became closely linked to breast cancer. My research suggests that as breast cancer was redefined in terms of estrogen, scientific understandings of the function of estrogen shifted as well: breast cancer researchers began to emphasize the growth-promoting ability of estrogen as a central aspect of its hormonal function. This prioritization of the growth functions of estrogen complicated the gendered assumptions upon which the notion of hormone-dependent cancers initially relied. Researchers and clinicians began to suggest that estrogen could exacerbate some breast cancers not because it should be understood primarily as a “female sex hormone,” but because it could promote tumor growth.

In the 1980s, three neurologists from Boston and Glasgow proposed that brain laterality and numerous human ‘abnormalities’ might have a shared hormonal cause. Norman Geschwind (1926–1984) and colleagues suggested that fetal testosterone regulates brain asymmetry and impacts other characteristics including hand preference, sexual orientation, mental abilities, the immune system, and the susceptibility to psychiatric illness. The neurologists produced no experimental data to back their hypothesis. They primarily based their model on a review of hundreds of publications from a wide range of times, places, and disciplines. My paper illustrates that the neurologists mobilized incoherent concepts of ‘the brain’ by drawing on such a variety of scholarly literature. The reviewed works promoted anatomical, hormonal, or genetic understandings of ‘the brain’, and each of these epistemic versions of ‘the brain’ had been assessed with distinct methods, ranging from lesion studies through questionnaires to behavioral observation. Geschwind and colleagues glossed over these substantial conceptual differences in their attempt to distill the heterogeneous literature into a grand unified theory of human life. Drawing from archival collections, published records, and oral history interviews, I show that the epistemic multiplicity of ‘the brain’ led to a tension between concepts of fixity (‘nature’) and plasticity (‘nurture’) in the neurologists’ understanding of the human. I argue that Geschwind and colleagues depended on testosterone to bridge these epistemic divides. Conceiving of this hormone as genetically regulated with anatomically localizable effects, the neurologists combined concepts of fixity and plasticity in a model that essentialized human character and behavior.