Contemporary society is based upon a heteronormative gender order: an order based on the idea that there are two opposite sexes that are attracted to each other. The gender order demands that we categorize people as women or men. People usually try to imitate what are perceived as ‘normal’ femininity or masculinity and the complex intersections between gender and sexuality are key to how this operates. Social rules about ‘normal’ gender and sexuality demand that you must be clear about who are boys and who are girls, so that boys and girls can grow up, fall in love with each other, and have more little boys and girls. French feminist (see Chapter 7) Monique Wittig (1992: 66) argues that ‘[t]he category of sex is a political category that founds society as heterosexual’, sexual difference is socially produced in this way in order to oblige women to reproduce the species. Crucial in this production is men’s appropriation of women’s productive and reproductive powers and their bodies through the marriage contract.

Judith Butler (1990; 1993; 2004) has developed Wittig’s ideas about heteronormativity (see Chapters 3 and 5) and queer theory generally (see Chapter 4 and Jagose, 1996; Seidman, 1996) has continued to explore connections between gender and sexuality and the implications of thinking about gay identities. Other texts deal with these connections in detail (for example, Beasley, 2005). The key issues are how gender relates to whom we desire, but also how desire corresponds to perceived differences between men’s and women’s bodies. In order to examine the social character of those differences sociologists need to engage with scientific understandings of ‘sex’ as rooted in physical biology, including psychological dispositions.