Social Identity Theory

Social identity theory (SIT) attempts to understand how social categorization affects intergroup behaviours (Tajfel and Turner, 1979).

SIT is associated with a number of pioneering studies, most of which rely on the 'minimal group paradigm'. In recent years, SIT has been explored with the use of additional types of study but I am going to discuss studies using the minimal group paradigm. Such studies are directly relevant to the evaluation of the theory and several have been instrumental in its development.

SIT is based on a number of inter-related concepts: social categorization, social identity, social comparison and positive distinctiveness. Social categorization divides the social environment into ingroups (to which an individual belongs) and outgroups (to which the individual does not belong). Social identity is the part of our self-concept based on knowledge of our membership of one or more social groups. It is separate from personal identity - which is the part of our self-concept that derives from the way we perceive our personality traits and the personal relationships we have with other people (Turner, 1982). Whereas personal identity is associated with interpersonal behaviours, social identity is related to intergroup behaviours.

Our social identity contributes to how we feel about ourselves, so we seek positive social identities to maintain and enhance our self-esteem. Positive social identities may result from the process of social comparison as we continuously compare our ingroups with relevant outgroups. This social comparison process is set in motion by our need for positive distinctiveness - the motivation to show the superiority of our ingroup compared to relevant outgroups. By thus establishing the superiority of our ingroup, we make sure that our social identities, and therefore our self-esteem, are positive enough.

Intergroup behaviours, the study of which forms the focus of SIT, are based on social identities and exhibit the following general characteristics:

* ingroup favouritism (the tendency to behave in ways that favour members of our ingroup compared to members of outgroups)

* intergroup differentiation (behaviour that emphasizes differences between our ingroup and outgroups)

* ethnocentrism (an ingroup-serving bias: positive behaviours by ingroup members tend to be internally attributed whereas negative behaviours receive a situational attribution; the reverse pattern is manifested when explaining positive and negative behaviours in an outgroup)

* conformity to ingroup norms (much greater than conformity to outgroup norms)

* stereotypical thinking (ingroupers and outgroupers are all perceived according to relevant stereotypes).

In this essay, I will concentrate on the crucial SIT phenomena of ingroup favouritism and intergroup differentiation. The other characteristics listed above highlight the diversity of phenomena that have been constructively addressed by SIT.

SIT has been supported by many experiments using the minimal group paradigm introduced by Tajfel (e.g. Tajfel et al., 1971). The technique defines ingroups and outgroups on arbitrary criteria such as by tossing a coin. Group members never meet or in any other way interact with one another. In fact, they do not even know who else belongs to their ingroup or to the outgroup. Tajfel et al. (1971) is an early