In social science, class is used to categorize people based on economic and social criteria. The concept has been the most relevant in Marxist theory, where social classes have different roles in the production of goods and services. Feminist and anti-racist critiques of traditional Marxist theory argue that a narrow focus on economic inequality and capitalist production model result to exclusion of the groups who do not fit the stereotypical notion of the white masculine workers. Class relations cannot be understood in isolation from other power structures, such as gender, ethnicity, functionality and sexuality. A working class background has different implications for women and men, since women have traditionally engaged in unpaid housework and men have been considered as breadwinners to justify a gendered division.