Dichotomy, from the Greek word dikhotomos, ‘divided in two’, is used in social sciences to describe something that is divided into two opposing categories. One example is the so-called gender binary, where women and men are viewed as two categories with traits (masculine and feminine) that are opposites and mutually exclusive (either/or). With this perception of gender, there is no room for nuances or hybrids, and the model excludes individuals who identify themselves as neither woman nor man (non-binary).

In a worldview characterised by dichotomies, it is common not only to see categories as opposites, but also to create hierarchies between them. This can be illustrated by means of the gender system theory, according to which each society creates and maintains a system in which women and men are assigned different tasks, roles and positions. The gender system is based on two principles: separation of the sexes and make superiority. This is expressed in for example a gender-segregated labour market, where women and men operate in separate sectors: areas such as health and human care have a large proportion of female workers, while for example construction is heavily male dominated. In addition, the things men do are considered more valuable, which is expressed in the observations that men earn more money than women and are also more likely to be found in powerful positions in society, for example as professors in academia and as chairs of corporate boards (see also power).

Both ecofeminist and postcolonial researchers have shown how a worldview characterised by dichotomies has legitimised domination and oppression: humankind’s dominance of nature, a patriarchal social order where women are subordinated to men, and the colonialism and racism when the white Europe has conquered other countries and ethnic groups (see also discourse, patriarchy, postcolonialism, racialisation). Throughout history, one part of each of these opposites (dichotomies) has been places above the other, so that association chains of super- and subordination are formed. Men, white Europeans, humankind, reason and Western science have been assigned superior value and a central position whereas women, racialised people regardless of gender, animals, nature, bodies, emotions and local forms of knowledge have been subordinated and marginalised (see also hegemony, situated knowledge, whiteness).