 In some ways, questions pertaining to the metaphysics of sex and gender resemble those pertaining to race: historically, descriptive and normative categories were conflated in simplistic biological theories. An important difference between sex/gender and race, however, concerns the distinction between sex and gender (Beauvoir 1949, West &amp; Zimmerman 1987). Many theorists propose that sexes are biological categories and that genders are categories of social norms and behaviors that are traditionally attached to sexes. However, other theorists argue that it is incorrect to regard sex as biological (Fausto-Sterling 2000, Butler 2004). Thus in the case of sex/gender, there are arguably multiple socially constructed categories that interact with one another; and some theorists reject the distinction between sex and gender (see entry on  feminist perspectives on sex and gender).