Editing Cognitive categorization (section)

=== Negative aspects ===
The activity of sorting people according to subjective or objective criteria can be seen as a negative process because of its tendency to lead to violence from a group to another.<ref name=":3" /> Indeed, similarities gather people who share common traits but differences between groups can lead to tensions and then the use of violence between those groups. The creation of social groups by people is responsible of a hierarchization of relations between groups.<ref name=":3">{{Cite journal |last=Tajfel |first=H |year=1982 |title=Social Psychology of Intergroup Relations |url=https://www.annualreviews.org/doi/10.1146/annurev.ps.33.020182.000245 |journal=Annual Review of Psychology |volume=33 |issue=1 |pages=1–39 |doi=10.1146/annurev.ps.33.020182.000245 |issn=0066-4308}}</ref> These hierarchical relations participate in the promotion of stereotypes about people and groups, sometimes based on subjective criteria. Social categories can encourage people to associate stereotypes to groups of people. Associating stereotypes to a group, and to people who belong to this group, can lead to forms of discrimination towards people of this group.<ref>{{Cite journal |last1=Hugenberg |first1=Kurt |last2=Bodenhausen |first2=Galen V. |year=2004 |title=Ambiguity in Social Categorization: The Role of Prejudice and Facial Affect in Race Categorization |url=http://journals.sagepub.com/doi/10.1111/j.0956-7976.2004.00680.x |journal=Psychological Science |volume=15 |issue=5 |pages=342–345 |doi=10.1111/j.0956-7976.2004.00680.x |pmid=15102145 |s2cid=14677163 |issn=0956-7976}}</ref> The perception of a group and the stereotypes associated with it have an impact on social relations and activities.

Some social categories have more weight than others in society. For instance, in history and still today, the category of "race" is one of the first categories used to sort people. However, only a few categories of race are commonly used such as "Black", "White", "Asian" etc. It participates in the reduction of the multitude of ethnicities to a few categories based mostly on people's skin color.<ref>Nadine Chaurand. Stéréotypisation. Catégorisation sociale. Dictionnaire historique et critique du racisme, PUF, 10p, 2013. ffhal-00966930</ref>

The process of sorting people creates a vision of the other as 'different', leading to the dehumanization of people. Scholars talk about intergroup relations with the concept of [[social identity theory]] developed by H. Tajfel.<ref name=":3" /> Indeed, in history, many examples of social categorization have led to forms of domination or violence from a dominant group to a dominated group. Periods of colonisation are examples of times when people from a group chose to dominate and control other people belonging to other groups because they considered them as inferior. Racism, discrimination and violence are consequences of social categorization and can occur because of it. When people see others as different, they tend to develop hierarchical relation with other groups.<ref name=":3" />