 Grosz’s endorsement of a biology which renders the sexual binary unassailable, has been criticized for going beyond recognizing the importance of the material, to privilege a particular biological account of matter (Jagger 2015). The history of sex difference research show that the biological theories, which give an account of sex differences, are the products of particular historical and culturally specific moments of production. Such a recognition has allowed biological accounts of sex differences to be revisited with an eye as to where cultural assumptions about gender have influenced them. Of key importance in this regard has been the assumption that there are simply two sexes, male and female, a model which has come increasingly under challenge. Fausto-Sterling points out the range of inter-sex bodies that are forced into a binary classificatory system (1992, 2000). She points out that “the varieties are so diverse … that no classificatory scheme could do more than suggest the variety of sexual anatomy encountered in clinical practice” (1993: 22). Oudshoorn (1994), in a genealogy of the emergence of the theory of sex hormones, shows how a model of binary sex differences prevailed, in a context in which dualistic notions of male and female could have been abandoned (see entry  feminist philosophies of biology  and also Fausto-Sterling 1992, 2000; Fine 2012, 2017). Lane argues that 