Harry Truman ended World War II by dropping two atomic bombs. As the cold war grew, American kids learned how to protect themselves from the A – bomb: duck and cover. Some parents built bomb shelters and debated the ethics of turning away or even shooting their less visionary neighbors when the time came. Gender politics became bound up with the new language of national security. As several historians have shown, this was an era in which stable domestic arrangements—that is, ‘‘traditional’’ family structures— were equated with and thought to guarantee domestic (and national) stability.

The equation of sexual order and nuclear containment worked both ways. Communist atomic power was regarded as a direct threat to the stability of American families. In 1951, the Harvard physician Charles Walter Clarke warned that atomic attack would destroy the normal social supports for family and community life, opening ‘‘the potential for sexual chaos.’’ Health profes­sionals, he suggested, should stockpile an ample supply of penicillin to treat a postatomic epidemic of venereal disease, while preparing for ‘‘a vigorous repression of prostitution, and measures to discourage promiscuity, drunken­ness and disorder.’’13

Sexual chaos even seemed to threaten national security from within. In 1948, for example, Guy Gabrielson, national chairman of the Republican party, wrote that ‘‘sexual perverts’’ had ‘‘infiltrated the government’’ and were ‘‘perhaps as dangerous as the actual Communists.’’14 Not only were ho­mosexuals weak willed, unmanly, and thus vulnerable to Communist infil­tration and threats, but their lifestyle (to coin a more modern usage) mocked the traditional family, weakening it in the same way that Communists, who urged that political loyalties supersede blood ties, sought to undermine capi­talist civilizations. Furthermore, the American male was having a masculinity crisis—a bad hair day writ large. As the historian Arthur Schlesinger, Jr., wrote at the time, the symptoms included an alarming merging of gender roles both at home and at work. A fascination with homosexuality, ‘‘that in­carnation of sexual ambiguity,’’ and with ‘‘the changing of sex—the Christine Jorgenson phenomenon—’’ expressed ‘‘a deeper tension about the problem of sexual identity.’’15

Postwar ideologues insisted that national security depended on women and men taking up their appropriate domestic roles. Women, many sug­gested, were naturally suited to roles as wives and mothers. In language that closely resembled the words used by contemporary biologists to describe fe­male differentiation in the embryo, a 1957 Ladies’ Home Journal article entitled ‘‘Is College Education Wasted on Women?’’ made the point clearly. College was a good place for women to look for husbands, but ‘‘certainly the happiest women have never found the secret of their happiness in books or lectures. They do the right thing instinctively.’’16

In contrast, and also in language that bore a striking resemblance to con­temporary writings about the biology of male development, men apparently needed substantial support and reassurance in order to fulfill their natural roles as breadwinners and husbands. Postwar propagandists fretted about the feminizing effects of a new and growing sector of the economy—the white – collar worker, the organization and advertising man—who sat at a desk all day, physically inactive and under great stress. One typical magazine article urged women to build up their mates’ sense of manliness, to consider that men who ‘‘spend their lives behind a big mahogany desk, or. . . in a lesser job,’’ need to ‘‘escape the doubts the best of them entertain about them­selves.’’ 17 They want a woman who can reassure them of their own masculinity by choosing them despite being attractive enough to interest other men.

But the era’s experts also emphasized that what men did in the domestic realm was crucial to maintaining their masculinity and building a manly next generation.18 Paternal intervention in child rearing was essential if one was to avoid raising a sissy boy. A 1950 articlein Better Homes and Gardens began, ‘‘Are we staking our future on a crop of sissies? . . . You have a horror of seeing your son a pantywaist, but he won’t get red-blooded and self reliance [sic] if you leave the whole job of making a he-man of him to his mother.’’19 A mother could ‘‘instinctively’’ raise a daughter, but her innate response to protect her son from harm interfered with his developing independence and manliness.20 Fatherhood itself became a new badge of manliness, even though parenting was not thought to come as naturally to men as to women. Men, the popular wisdom went, had to attend classes on marriage and the family to learn from the experts how to do it right.

Despite the widespread ideology of sexual and gender role conformity that prevailed in films, magazines, government policies, and school curricula, the decade we tend to remember as the ‘‘Leave It to Beaver’’ era saw its share of challenges to mainstream notions of gender. The publication of the Kinsey reports, for example, challenged accepted views of American sexual behavior, by suggesting that homosexual encounters, premarital sex, and masturbation were widespread and biologically normal.21 With the 1953 founding of Play­boy magazine, Hugh Hefner created a cultural space for the philandering yet highly masculine bachelor and a model of sorts for the sexually liberated woman. And, during the late 1930s, the Beat Generation challenged conven­tional definitions of masculinity at the same time that underground homosex­ual rights movements slowly emerged from obscurity.

Scientists who studied animal sexuality in this era, then, worked with complex cultural stock. On the one hand, they could formulate their meta­phors and theories in terms of mainstream accounts of gender. On the other, the very existence of countercurrents that challenged such standard view­points made it possible for some scientists to envision new ideas about animal sexuality. Consider studies on the development in fetuses of anatomical differences between males and females. In 1969, the French embryologist Al­fred Jost summarized the conclusions of his previous twenty years of work in this field: ‘‘Becoming a male is a prolonged, uneasy and risky adventure; it is a kind of struggle against inherent trends toward femaleness.’’22 All males, be they rats, guinea pigs, or humans, had to strive against an inner femininity. Just as the advice magazines of the 1930s had warned, the danger of sissydom lurked beneath the masculine surface. How did Jost come to this conclusion, which closely echoed the gender anxieties ofthe period? How did this conclu­sion, gained from careful studies of male and female embryos, translate into research on the relationship between hormones and masculine and feminine behaviors?

When, in 1947, the thirty-two-year-old Jost initiated a series of publica­tions describing his experiments on the development ofmale and female anat­omy in rabbits and rats, he entered into a debate about whether androgens and estrogens were equal-opportunity hormones.23 Researchers in the previous decade had agreed that injecting testosterone or other androgens into devel­oping females masculinized their internal ducts and external genitalia. More controversial was the question of whether estrogens exerted a parallel effect on male embryos. Eugen Steinach’s earlier models of male and female hor­monal physiology framed the discussion. The Scottish researcher B. P. Wiesner, for example, found that estrogens (he still called them thelykinins) injected into newborn male rats (whose external genitals are poorly devel­oped at birth) inhibited penile growth, producing feminized males. He be­lieved, however, that the estrogen inhibited the testis rather than acting di­rectly on the genitalia. He thus rejected a di-hormonic theory that animals acquired masculinity and femininity through the action ofequal but opposite­acting hormonal systems. Wiesner wrote: ‘‘[the mono-hormonic theory] rec­ognizes the absolute dominance of male hormone in developmental processes and it describes the conditions under which female differentiation may occur as the absence of any, rather than the presence of a specific, sex hormone.”24

In contrast, researchers at Northwestern University Medical School’s De­partment of Physiology and Pharmacology argued that testosterone and estro­gen played comparable roles in male and female development. In one set of experiments R. R. Greene and his associates injected high concentrations of estrogenic hormones into pregnant rats. Males born to the treated females had ‘‘external genitalia of the female type and three to six pairs of well-developed nipples.’’ Their testes did not descend toward the scrotum, but remained in a position more typical of ovaries. Furthermore, the male duct system did not grow properly, the prostate did not develop, and these rats had partial devel­opment of the upper vagina, uterus, and oviduct. Finally, Greene and co­workers noted a paradoxical effect of estrogen injection: some of the female embryos found in injected pregnant mothers emerged with masculine ana­tomical characters. So the estrogen feminized male fetuses but masculinized female ones. Greene and colleagues found ‘‘the available facts more compati­ble with the di-hormonic theory.’’25 Indeed, taken on their own, the results of hormone-injection experiments in mice and rats seemed to indicate that the active effects of estrogens and androgens appeared virtually parallel (see ta­ble 8.і)

In an attempt to resolve the mono – versus di-hormonic debate, Jost chose an innovative experimental technique. Operating on rabbit fetuses still inside the mother, he eliminated the embryonic gonad. Both technically difficult and physiologically more ‘‘normal’’ than injecting large doses of purified hor­mones, his approach produced information about the roles played by the em-

TABLE 8.1 Summary of Androgen and Estrogen Effects on Early Fetal Development

ANDROGEN EFFECTS ON FEMALE FETAL DEVELOPMENT

ESTROGEN EFFECTS ON MALE FETAL DEVELOPMENT

ANATOMICAL

STRUCTURE

RAT

MOUSE

RAT

MOUSE

Gonad position

Masculinized

Masculinized

Feminized

Feminized

Female internal genitalia

No effect

No effect

Stimulated

Stimulated

Male internal genitalia

Stimulated

Stimulated

Inhibited

Inhibited

External genitalia Masculinized

Masculinized

Feminized

Feminized

Source: Adapted from Greene et al. 1940b, tables 3 and4, pp. 333—34.

bryo’s own gonadal hormones. He tried four different types of experiments: fetal castration (removal of either the testes or the ovaries), fetal parabiosis (the joining together of the circulatory systems of two developing embryos), grafting embryonic testes or ovaries onto an embryo of the ‘‘opposite’’ sex, and hormone injection.26

Jost’s techniques were new to those who studied mammals, and his success with these demanding surgeries drew attention to his work. The castrations, performed between nineteen and twenty-three days of fetal development, produced striking results. In castrated male embryos, developing masculine structures such as the epididymis (a duct that, when mature, carries sperm from the testes to the outside during ejaculation) disintegrated, while the structures forming the oviducts, uterus, and part of the cervix developed as if the embryo were female rather than male. Furthermore, the fetally cas­trated male rabbit developed a vagina and a clitoris rather than a penis and scrotum. In contrast, removing the ovary of a fetal female did not obviously affect the course of sexual development. Oviducts, uterus, cervix, and vagina all differentiated in near normal fashion, although if the castration was per­formed early enough, these organs did not grow to full size.

What struck Jost especially was that without a fetal testis, the male duct system degenerated, while even in male embryos the female system devel­oped. What made these two duct systems behave so differently? Since males

had no ovaries, those structures could not be responsible for supporting con­tinued female development. Wondering whether maternal estrogen or per­haps estrogen made by the male’s adrenals might cause female duct develop­ment, Jost performed additional experiments, concluding finally that “a crystal of androgen could counteract the absence of testicles and assure development of masculine somatic characteristics!’27

Putting the whole story together, Jost concluded, first, that the female duct system developed without stimulation from the embryonic ovary. Hence, female structures could differentiate in both castrated males and fe­males. The testes, he theorized, made some substance that inhibited female duct development. The fact that female ducts developed even in castrated male embryos implanted with testosterone led him to postulate that two sub­stances must be involved. One, testosterone, stimulated development of male ducts and genitalia. The other, at the time merely postulated but later identi­fied as a proteinlike hormone called Mullerian Inhibiting Substance (MIS), caused the female ducts to degenerate.28 The fetal testis normally makes both chemicals.

Cautiously and in some detail, Jost discussed the implications of his results for mono – and di-hormonic theories of sexual development. First, he noted that the male and female duct systems, originally present in both sexes, had rather different developmental potentials. No matter the genetic sex of the embryo, for example, the female ducts could develop if not inhibited by a testicular secretion, while the male ducts degenerated unless grown in the presence of testosterone. Did these results lend support to Wiesner’s mono­hormonal theory? Jost reminded his readers that when the ovaries were re­moved at an early stage, the female duct system did not grow to a normal size. Thus, it was ‘‘probable that the ovary also produces a morphogenetic secretion, but that it, without a doubt, plays a more limited role than the testicular secretion.’’ Furthermore, the fact that ovarian action did not cause the breakdown of the male duct system did not prove that the ovaries played no role. There could, Jost suggested, be some sort of double assurance—that is, some other source of hormone could be called into action in the ovaries’ absence. He suggested that future experiments focus on the role of the ovary, on the physiology of the fetal ovary, and on castrations performed at earlier stages of development.29

Despite the skills and insights that led him to challenge his colleagues’ theories, Jost failed to notice that his theory adopted wholesale the metaphor of female lack and male presence. From the 1950s through the mid-1960s he referred to females as the neutral or anhormonal sex type. They became fe­males, according to him, because they lacked testes, while the testes played the principal role in separating male from female development. By the early 1970s, Jost described male development as a heroic feat, a successful traverse of a road fraught with danger. The testes imposed masculinity with the help of a tiny yet powerful Y chromosome. The male embryo struggled against the inherent push toward femininity.30

Both the rhetorical and theoretical structures of Jost’s work, and of other scientific investigations into hormones more generally, seemed to mirror on­going social debates about gender. Di-hormonic ideas were compatible with a vision in which the sexes occupied separate spheres. Scientists understood each sex as formed through active and specifically controlled processes. Di – hormonic theories thus understood both male and female development as processes that needed accounting for; the parallel notion of maleness and fe­maleness might seem more readily to suggest male and female equivalence. In contrast, mono-hormonic theories emphasized the perilous nature of mascu­line development, using language suggesting the dangers to men of underlying femininity: ‘‘Masculine characteristics of the body have to be imposed in males. . . against a basic feminine trend of the mammalian body.’’ Females, in contrast, represented the natural starting template. In Jost’s theory, then, masculinity, in the body biologic as in the body politic, required aggressive action to maintain itself.31

The longstanding notion that femaleness represented a bodily absence, while a physical presence defined maleness, in combination with postwar in­sistence on the need for men to build their masculinity and women to follow passively their natural inclinations, partly explains why Jost and others ac­cepted an underproven hypothesis.32 The unexamined rhetoric of female ab­sence also helps account for the fact that neither Jost nor others performed extensive, detailed experiments to find out just what did govern female devel­opment if, as the fetal castration data suggested, the fetal ovary played a minor role.33 If female development was a state of nature, only male development required explanation, and the phrase ‘‘sexual differentiation’’ really meant ‘‘male differentiation.’’34

Jost’s model of the female as the product of an absence persists even today. These days scientists study the genes involved with driving the development of the ovary or testis itself.35 But until recently, the idea that females ‘‘just happen’’ has been a staple of even the most sophisticated scientific thought. The author of one scientific article, discussing the importance of particular genes for the development of an ovary or testis after the sperm has delivered either a second X or a Y chromosome to the egg,36 writes: ‘‘In the presence of a Y chromosome. . . the gonads. . . form as testes. … In the absence of testes female. . . genitalia develop. . . . Sex determination can thus be equated with determination of testis formation.’’37 ‘‘In the human. . . the female is the constitutive sex and the male the induced sex. Therefore sex deter­mination can be considered the equivalent of being determined as male,’’ writes another scientist.38 ‘‘The female developmental pathway,’’ says a third, ‘‘has often been referred to as the default pathway.’’39

The scientific model of sexual development that won out over others is the one that borrowed most from, and best fit with, conservative notions that characterized femaleness by passivity and lack, but it has done more than just bolster conservative viewpoints. Indeed, the idea that all embryos start as female, that the ‘‘natural ground state’’ is feminine and maleness a mere after­thought, has delighted some feminists. The feminist science writer Natalie Angier, for instance, writes that ‘‘from a biological perspective women are not the runners-up; women are the original article. We are Chapter i, lead paragraph, descendants of the true founding citizen of Eden.’’40 Just as the metaphor of a female ground state has cultural purchase in the arena of gender politics, it has opened doors to important scientific insights. Evolutionarily, for example, the idea suggests that females preceded males onto this earth, that the male is derived from the female—Adam’s Rib in reverse. This idea has fueled fascinating research on topics that include the evolution of the Y chromosome and the varieties of sexual systems found in the animal world.41

But the metaphor giveth and the metaphor taketh away. Think of the dual­isms the default metaphor generates. If the female plan is natural, does that equate females with nature, thus implying that culture is masculine? And if femininity can contaminate or undermine masculinity, then does ‘‘main­taining masculinity require suppression of the feminine’’?42

When Jost wrote that ‘‘Becoming a male is a prolonged, uneasy, and risky adventure; it is a kind of struggle against inherent trends toward femaleness,’’ he constructed a narrative, in which the adventure, the risk, and the heroic accomplishment all belong to the male. Building on Jost’s narrative, many current chronicles of primary sex determination have little to say about fe­male development. For years the phrase ‘‘sex determination’’ has been ‘‘con­sidered the equivalent ofbeing determined as male.’’43 Accepting such a view­point, I argue here and elsewhere, has stimulated a great deal of research into the mechanisms (genetic and hormonal) of male development, but few have doggedly pursued the mechanism of female development.44 In a 1986 review, the geneticists Eva Eicher and Linda L. Washburn criticized research on sex determination for ‘‘presenting the induction of testicular tissue as an active. . . event while presenting the induction of ovarian tissue as a passive (auto­matic) event. Certainly the induction of ovarian tissue is as much an active, genetically directed developmental process as is the induction of testicular tissue. . . . Almost nothing has been written about genes involved in the in­duction of ovarian tissue from the undifferentiated gonad.’’45 Only in the 1990s did theories of female development begin to emerge.46

The lack of scientific attention to female development is not due simply to the power of the presence/absence metaphor. Indeed, other metaphors— especially narratives about master genes and switches47— and the animals themselves also account for the scientific history of male and female develop­ment. For example, when one sex researcher looked for active effects of estro­gen on female guinea pig development, he found that estrogen injections caused the test animals to abort, making it difficult to follow up on this line of research.48 He decided that it was more prudent for his career to pursue a line of research more likely to give publishable results in a reasonable period of time.

Like most scientists working on mammalian steroid hormones, Jost hoped that his work would apply, both practically and theoretically, to humans. Al­most from the beginning, he interacted with medical scientists concerned with human development. In 1949, following up on contacts provided by his brother, Dr. Marc Jost, Alfred Jost visited Johns Hopkins University. There he met Dr. Lawson Wilkins, a pioneer in the study of human intersexuality (see chapters 2—4). An intense afternoon of discussion of Wilkins’s clinical cases convinced him of Jost’s mono-hormonic account of mammalian sexual development, a viewpoint he applied immediately in his forthcoming book on sexual malformation in humans. In turn, Jost noted how important the ap­proval of this senior, renowned clinician was to the younger experimental scientist (Jost was thirty-three, Wilkins fifty-five, at the time of the en­counter).49