Social Identity Theory (SIT) is a theory that was proposed by Tajfel and Turner in the 1970s and that attempts to explain intergroup behaviours. More specifically, an original aim of SIT was to help explain situational factors in behaviour. The theory consists of four interrelated concepts:

  • social categorization
  • social identity
  • social comparison
  • and positive distinctiveness.

These concepts outline the various ways in which individuals’ behaviour can be shaped by belonging to a social group. Furthermore, SIT attempts to explain the various intergroup behaviours, such as the need to positively distinguish one’s own ingroup from other outgroups.

SIT is based on the belief that individuals want to increase their self-esteem by their belonging to a group and their behaviour within that group. Because of this, a natural desire occurs to increase the social standing of one’s ingroup. As a result, groups demonstrate the four primary elements of SIT. This is because when we belong to a group we assume we have similar beliefs as other members and a bond is formed.

The first aspect of SIT is social categorization. Put simply, this is the desire for groups to distinguish themselves from one another into clear categories. This has three effects. First of all, it reduces the perceived differences that exist in the out group. Second, it reduces the perceived differences of the in group and finally, it increases the perceived differences between the ingroup and outgroups. This aspect of SIT is known as the category accentuation effect.

Similar to this notion is the idea of positive distinctiveness. This is the desire for the ingroup to maximize their differences from the outgroups and to make the ingroup seem superior to others. This is achieved through a variety of social comparison behaviors. One of these is known as ethnocentrism. This is basically a form of self-serving bias for an entire group. For instance, if an ingroup member does something positive it will be attributed to their disposition, similar to if an outgroup member does something negative. By this form of ethnocentrism the ingroup tries to differentiate itself in a positive manner from the outgroup.

Various other intergroup behaviours exist, such as the demonstration of ingroup favouritism, stereotyping and outgroup discrimination. All these behaviours serve to increase the groups ingroup bias and consequently the in-group’s self-esteem.