Social Identity Theory

Social Identity Theory Definition and History

Social identity theory explains how the self-concept is associated with group membership and group and intergroup behavior. ISocial Identity Theoryt defines group membership in terms of people’s identification, definition, and evaluation of themselves as members of a group (social identity) and specifies cognitive, social interactive and societal processes that interact to produce typical group phenomena.

Originating in the work of Henri Tajfel in the late 1960s and collaboration with John Turner in the 1970s, social identity theory has a number of different conceptual foci. The two most significant are the social identity theory of intergroup relations and the social identity theory of the group, the latter called self-categorization theory. Social identity theory has developed to become one of social psychology’s most significant and extensively cited analyses of inter-group and group phenomena, for example, prejudice, discrimination, stereotyping, cooperation and competition, conformity, norms, group decision making, leadership, and deviance.

How People Represent Themselves

People have a repertoire of different ways to conceive of themselves; they have many different identities that can be classified as personal identities or social identities. Personal identities are definitions and evaluations of oneself in terms of idiosyncratic personal attributes (e.g., generous, shy), and one’s personal relationships (e.g., X’s friend, Y’s spouse). Social identities are definitions and evaluations of oneself in terms of the attributes of specific groups to which one belongs (e.g., male, nurse, Hindu). Personal identity is tied to the personal self and associated with interpersonal or idiosyncratic individual behaviors; social identity is tied to the collective self and associated with group and intergroup behaviors. Recently, theorists have argued that in some cultures, social identity rests more on networks of relations within a group and is thus associated with the relational self.

How People Represent Groups

Human groups are social categories that people mentally represent as prototypes, complex (fuzzy) sets of interrelated attributes that capture similarities within groups and differences between groups. Prototypes maximize entitativity (the extent to which a group is a distinct entity) and optimize metacontrast (the extent to which there is similarity within and difference between groups). If someone says to you, “Norwegian,” what comes immediately to mind is your prototype of that national group. Overwhelmingly, people make binary categorizations in which one of the categories is the group that they are in, the ingroup. Thus, prototypes not only capture similarities within the ingroup but also accentuate differences between a person’s group and a specific outgroup. Ingroup prototypes can therefore change as a function of which outgroup you are comparing your group to. In this way, prototypes are context dependent.

Categorization and Depersonalization

The process of categorizing someone has predictable consequences. Rather than seeing that person as an idiosyncratic individual, you see him or her through the lens of the prototype; the person becomes depersonalized. Prototype-based perception of outgroup members is more commonly called stereotyping; you view them as being similar to one another and all having outgroup attributes. You can also depersonalize ingroup members and yourself in exactly the same way. When you categorize yourself, you view yourself in terms of the defining attributes of the ingroup (self-stereotyping), and, because prototypes describe and prescribe group-appropriate ways to think, feel, and behave, you think, feel, and behave group prototypically. In this way, self-categorization produces normative behavior among members of a group.

Feelings for Group Members

Social categorization affects how you feel toward other people. Feelings are governed by how prototypical of the group you think other people are, rather than by personal preferences, friendships, and enmities; liking becomes depersonalized social attraction. Furthermore, because within one’s group there is usually agreement over prototypicality, prototypical members are liked by all; they are popular. Likewise, less prototypical members are unpopular and can be marginalized as undesirable deviants. Another aspect of social attraction is that outgroup members are liked less than ingroup members; outgroupers are very unprototypical of the ingroup. Social attraction also occurs because one’s ingroup prototypes are generally more favorable than one’s outgroup prototypes; thus, liking reflects prototypicality and the valence of the prototype.

Intergroup Behavior

The tendency for ingroup prototypes to be more favorable than outgroup prototypes represents ethnocentrism, the belief that all things ingroup are superior to all things outgroup. Ethnocentrism exists because of the correspondence, through social identity, between how the group is evaluated and how a person is evaluated. Thus, intergroup behavior is a struggle over the relative status or prestige of one’s ingroup, a struggle for positive ingroup distinctiveness and social identity. Higher status groups fight to protect their evaluative superiority; lower status groups struggle to shrug off their social stigma and promote their positivity.

The strategies that groups adopt to manage their identity depend on subjective belief structures, members’ beliefs about the nature of the relationship between their group and a specific outgroup. Beliefs focus on status (What is my group’s social standing relative to the outgroup?), stability (How stable is this status relationship?), legitimacy (How legitimate is this status relationship?), permeability (How easy is it for people to change their social identity by passing into the outgroup?), and cognitive alternatives (Is a different intergroup relationship conceivable?).

A social mobility belief structure hinges on a belief in permeability. It causes members of lower status groups as isolated individuals to disidentify from their group to try to join the higher status outgroup; they try to “pass.” A social change belief structure hinges on acceptance that permeability is low. It causes low status groups to engage in social creativity, behaviors aimed at redefining the social value of their group and its attributes, coupled with attempts to avoid (upward) comparison with higher status groups and instead engage in (lateral or downward) comparisons with other groups lower in the social pecking order. Where a social change belief structure is coupled with recognition that the social order is illegitimate, group members engage in social competition, direct competition with the outgroup over status, which can range from debate through protest, to revolution and war.

Social Identity Motivations

The group pursuit of positive distinctiveness is reflected in people’s desire to have a relatively favorable self-concept, in this case through positive social identity. The self-esteem hypothesis draws out this logic: Social identity processes are motivated by the individual pursuit of a relatively favorable self-concept and possibly by the global human pursuit of self-esteem. Research suggests that group membership generally does make people feel good about themselves, even if the group is relatively stigmatized, but feeling good or bad about oneself does not easily predict whether one will actually identify with a group.

According to uncertainty reduction theory, there is another basic motivation for social identity processes. People strive to reduce feelings of uncertainty about their social world and their place within it; they like to know who they are and how to behave, and who others are and how they might behave. Social identity ties self-definition and behavior to prescriptive and descriptive prototypes. Social identity reduces uncertainty about who you are and about how you and others will behave, and is particularly effective if the social identity is clearly defined by membership in a distinctive high entitativity group. Research confirms that uncertainty, especially about or related to self, does motivate identification particularly with high entitativity groups.

When Does Social Identity Come into Play?

A social identity comes into play psychologically to govern perceptions, attitudes, feelings, and behavior when it is psychologically salient. People draw on readily accessible social identities or categorizations (e.g., gender, profession), ones that are valued, important, and frequently employed aspects of the self-concept (chronically accessible in memory), or because they are self-evident and perceptually obvious in the immediate situation (situationally accessible). People use accessible identities to make sense of their social context, checking how well the categorization accounts for similarities and differences among people (structural/comparative fit) and how well the stereotypical properties of the categorization account for people’s behavior (normative fit). People try different categorizations, and the categorization with optimal fit becomes psychologically salient. Although largely an automatic process, salience is influenced by motivations to employ categorizations that favor the ingroup and do not raise self-uncertainty.

Social Influence in Groups

People in groups adhere to similar standards, have similar attitudes, and behave in similar ways. They conform to group norms and behave group prototypically. Self-categorization is the cognitive process responsible for an individual group member behaving prototypically, transforming his or her self-concept and behavior to be identity-consistent. In gauging what the appropriate group norm is, people pay attention to the behavior of people who are most informative about the norm, typically highly prototypical members and leaders, but also, as contrast anchors, marginal members and deviants, and even outgroup members (referent informational influence theory).


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  3. Tajfel, H., & Turner, J. C. (1986). The social identity theory of intergroup behavior. In S. Worchel & W. Austin (Eds.), Psychology of intergroup relations (pp. 7-24). Chicago: Nelson-Hall.
  4. Turner, J. C., Hogg, M. A., Oakes, P. J., Reicher, S. D., & Wetherell, M. S. (1987). Rediscovering the social group: A self-categorization theory. Oxford, UK: Blackwell.