Social identity is defined as "the individual's knowledge" of personal membership in specific social groups, together with the "emotional value and significance" placed on such membership by the individual (Tajfel, 1972, p. 31). Social identity, thus, is closely related to self-concept.
Individuals apply the process of categorization to "partition the world into comprehensible units" (Abrams & Hogg, 1994, p. 2). This process is accorded a central role in social identity theory. Categorization "involves the psychological accentuation of differences between categories and the attenuation of differences between objects within categories" (Tajfel & Wilkes, 1963, pp. 101-114). Accentuation occurs only on those dimensions believed by an individual to be correlated with the categorization process (Abrams & Hogg, p. 3). An individual can derive "a sense of involvement, concern and pride . . . from one's knowledge of sharing a social category membership with others, even without necessarily having close personal relationships with, knowing or having any material personal interest in their outcomes" (p. 3). To "the extent that the in-group is perceived as both different and better than the out-group, . . . one's social identity is enhanced" (p. 3).
The process of categorization "produces the search for distinguishing features" (Abrams & Hogg, p. 3). The need by an individual for a positive identity motivates an effort to differentiate in favor of the in-group. The process of social comparison then is used to perform a selective accentuation of intergroup differences. Within the context of social identity theory, thus, self-concept reflects "a collection of self-images which vary in terms of the length of their establishment, complexity and richness of content" (p. 3).
When "social identity is salient one acts as a group member, whereas when personal identity is salient, one does not (Abrams & Hogg, p. 4). Self-concept as a m...