The phenomenon of categorization could be colloquially referred to as pigeonholing. In this process, people are collected into a defined social group, a collective. Various characteristics are ascribed to this collective as a unifying element, e.g. gender, race, culture, class or sexuality. Categorization occurs because people need uniqueness in their lives in order to more easily understand social contexts. The mechanism of categorization, which is close to essentialism, is therefore about unambiguity in a social context. At the same time, categorization counteracts ambiguity.

However, because a complete elimination of ambiguity is not possible, further subcategories are created within the categorizations. In this way, the greatest possible degree of unambiguity is created within a subcategory. Thus, this form of subdivision of people works against any diversity. For categorizations – which, for example, lead to a juxtaposition of cultures and people instead of a togetherness – do not have an inclusive or integrative effect; they separate. As a result, there is not more acceptance, but at most tolerance of the other in the sense of (reluctant) acquiescence.

Sexuality can serve as an example of categorization: It was not until the late 19th century that the concept of sexuality as an identity-forming characteristic emerged. People were divided into homosexuals or heterosexuals (further categorizations followed over the years). Previously, in what might be called “sex before sexuality,” persons had (non)same-sex sex that was morally valued but not considered an integral part of their personality. Thus, people were not categorized on the basis of sexual intercourse. It is only with the emergence of sexuality as a marker of identity that this category appears, by which people henceforth distinguished groups from one another.

The desire to categorize in order to make the world more understandable leads to ambiguity intolerance. Against the background of the accompanying feeling of belonging to a certain group, with which the individual identifies himself or with which he is equated from the outside, a demarcation also takes place. These demarcation mechanisms can result in racism, antiziganism, anti-Semitism, rejectionism, classism, sexism or homophobia, among other things.