In western science and common parlance prior to around 1700, women and men were understood not as anatomically different but as two vari­ations of the same sex. In the scientific version of this ‘one-sex’ model women were supposedly ‘imperfect’ versions of men, their genitalia were described as being the same as men’s, but on the inside rather than out – side. The ovaries were seen as internal testes while the shaft of the vagina tipped by the clitoris was thought equivalent to the penis. In other words, women’s reproductive organs were understood as like men’s, except folded up inside. Just because women and men were understood as being similar does not mean that they were thought equal. Woman’s ‘unopened’ genitalia were thought to reflect their incompleteness in comparison to man’s godly perfection (Laqueur, 1990). This one-sex model is rather different to a more recent obsession with distinguishing males from females as completely different types of body that develop in the womb and emerge from it as distinct. The one-sex view placed less social boundaries upon bodies because individuals were not seen as inherently feminine or masculine. Femininity and masculinity were seen as shades of everyone’s being, rather than oppositions. This view lent itself to conceptions of social status as something that should be used to control bodies. The higher your place in the social hierarchy the more you were expected to control your body, for example how and what you ate or the manner of blowing your nose (Elias, 2000/1939). More mod­ern ideas differ in assuming that biological differences form a ‘natural’ basis for a person’s position in the social hierarchy. For example, the idea that people with black skin were ‘naturally’ inferior was used to justify their low status within the apartheid system in South Africa in the late twentieth century. Similarly, the idea that women’s reproductive systems made them irrational was, and sometimes still is, used to argue that they are not ‘naturally’ suited to the serious business of ruling the world. If social status is thought to be based on particular physical characteristics,

then those characteristics become seen as significant. Not all physical differences take on such importance; for example eye colour is usually neither a help nor a hindrance to social success. On the other hand, the kinds of physical difference supposed to exist between women and men are thought to be of major significance in determining what kinds of lives individuals will lead. This view emerged as the dominant model used to understand sex difference, shifting from a one-sex to a two-sex basis from the eighteenth century onwards.

Understandings of sex that developed in the twentieth century sug­gest that foetuses start out the same, but gradually start to take different paths in developing sexed bodies, chromosomes and hormones. John Money is a psychologist whose explanations of how a foetus develops sex were very influential, especially in the early sociology of gender (for example, Oakley, 1972). John Money and Patricia Tucker (1975) explain how sex develops in terms of ten steps. First, they argue that chromoso­mal sex emerges as either an X or a Y chromosome becomes present. Females are XX and males are XY. Secondly, gonadal sex is established when the X or Y chromosome ‘instructs’ the fetal gonad to develop into a testis or an ovary. Thirdly, fetal hormonal sex is decided when the testis or ovary produces a ‘male’ (more testosterone) or ‘female’ (more oestrogen and progesterone) balance of hormones. Money argues that these differences in hormonal balance influence the following steps. The fourth step he identifies occurs when internal morphological sex (the development of bodily differences inside the body — for example a womb) is produced by hormonal action. In the fifth step external morphological sex (anatomical differences on the outside of the body — for example a penis) develops. According to Money the sixth step establishes brain sex (the development of potentialities such as a tendency to ‘like strenuous physical activity’ (Money and Tucker, 1975: 70) laid down by the mix of prenatal sex hormones an individual received). All the steps — but especially external morphological sex — are used once the child is born to determine the seventh step, which is sex of assignment and rearing. Money then thinks that to become ‘properly’ male or female a person must develop pubertal hormonal sex (as increased production of either testosterone or oestrogen starts turning boys into men and girls into women), an appropriate gender identity and role, and lastly have the ability to procreate (procreative sex) (Fausto-Sterling, 2004: 343). However this is now considered a rather simple story of sex development.

The two-sex model in which female and male foetuses ‘fork off’ from each other is open to a number of criticisms. First, this story of sex development fails to acknowledge that chromosomes are no guarantee of sex. The presence or absence of a hormonal substance called testis­determining factor (TDF), not the chromosome alone, determines whether gonads become testes or ovaries. Also there are other variations

of chromosomal ‘sex’, such as XXY, XXYY and many more (Hird, 2004: 47—8), which need to be thought of not simply as ‘detours’ (Money and Tucker, 1975:49).As for hormonal sex, while there is typically a difference between women and men in the balance of the different types of hormones, the differences are very slight. Women and men have the same hormones in very similar amounts. Women have testosterone among other hormones and men have oestrogen. Women tend to produce more oestrogen and progesterone, while men usually produce more testosterone and androgens (Oudshoorn, 1994).To call some hormones ‘male sex hormones’ and others ‘female sex hormones’ is misleading given that we all have them both and some women (for example some post-menopausal women) may have more testosterone than some men. The key thing is that the families of hormones previously labeled by scientists as ‘female’ or ‘male’ (they later added androgens which were thought ‘bisexual’), are all extremely chemically similar (as Money admits). What is most noticeable is the similarity in our hormonal make up. Hormones play a part in sex development, but it is unlikely that they determine ‘masculine’ or ‘feminine’ behaviour as directly as Money implies, or in the crude way people often assume within everyday talk about testosterone-fuelled aggression, or the supposed irrationality of women boosted by their hormonal cycles. Overall there are problems with the idea of sex determination as a straightforward process in which male bodies distinctly fork off from female bodies and take on masculinity and femininity respectively (Fausto-Sterling, 2000; 2004).

Feminist biologists such as Linda Birke (1999), Nellie Oudshoorn (1994), and Ann Fausto-Sterling (2000; 2004) all point out that scientists have to interpret what they see and that their own social understandings of what it means to be male or female influence those interpretations. Oudshoorn (1994), for example, argues that early twentieth century dis­cussions of sex differences continued to be influenced by long-standing common sense views of sex as an either/or opposition. These made it difficult to account for new evidence that emerged suggesting that women’s and men’s hormonal makeup was similar. Oudshoorn argues that there is no natural truth to the body but only interpretations of it. Although interpretations are crucial, this does not quite account for why scientists would bother to change their interpretations unless they had discovered something new when looking at bodies. However, what they see is usually limited by their fragmented approach. Scientists are typically looking at bits of bodies — cells, genes, chromosomes, or hormones in isolation. And what scientists are able to ‘see’will depend upon the frameworks in which they are working. Nevertheless, in trying to understand things that do not make sense within that framework, interpretations — and indeed the framework itself — can change. Knowledge is often advanced by scientists debating the best way to interpret scientific findings. For

example, Ann Fausto-Sterling (2004) is sceptical about geneticists’ claims that there is a master sex-determining gene on the Y chromosome (called SDY) and when this is present a male is formed. Fausto-Sterling argues that the language used in this interpretation implies that in the absence of SDY females ‘just naturally happen’. In this interpretation maleness comes across as an active presence but one always in danger of not successfully completing the steps needed to become male. Fausto-Sterling (2004) points out that this interpretation reflects social stereotypes about women as passive and men as active.

Interpretations of the link between homosexuality and biology also reflect stereotypes about gender. There are many putative associations between homosexuality and hormones, and questions about whether there is a homosexual gene. A lot of studies have been done on the relationship between hormonal levels and sexual orientation, but most are affected by the scientists’ cultural assumptions. Having looked at many of these studies, Hird (2004:40—2) notes that in some of them male homosexuals have been mistakenly assumed to be ‘feminine’ and female homosexuals ‘masculine’. The scientists then set up hypotheses that gay men will have less testos­terone than heterosexual men and gay women will have more testosterone than straight women. Most of the studies have found this not to be the case and she asserts that no association between hormonal levels and homosex­uality has been proven. What this illustrates is that although scientists may strive to be objective, socio-culturally specific assumptions about how the world works can become entangled in their interpretations of sex.