  One of the first theoretical advances of second wave feminism was to separate out biological conceptions of women’s identity from socially-constructed ones in order to disprove the notion that biology was destiny and hence that women’s main role was as mothers and caregivers. Drawing on the social sciences and psychoanalytic theory, anthropologist Gayle Rubin developed an account of a “sex/gender system” (Rubin 1975; Dietz 2003, 401; and the entry on   feminist perspectives on sex and gender).  The sex/gender distinction pointed to “a set of arrangements by which the biological raw material of human sex and procreation is shaped by human, social intervention” (Rubin 1975, 165). While biological sex was fixed, in Rubin’s view, gender was a social construction that served to divide the sexes and privilege men. Because gender was mutable, the sex/gender distinction gave feminists a powerful tool to look for ways to address women’s oppression.