Gender refers to the socially constructed roles, responsibilities, identities, and expectations assigned to men and women by society, as opposed to sex which refers to biological and physiological differences. Gender is influenced by social and cultural factors rather than biology alone. Sociological perspectives on gender include functionalism, which views traditional gender roles as serving important social functions, and feminism, which argues that patriarchal societies promote gender inequality that benefits men over women. Evidence from different cultures demonstrates that gender roles vary significantly across societies and over time, supporting the view that gender is socially constructed rather than innate.