Identity
The term identity implies a construct that gives the self a meaning or purpose. Weigert, Teitge, and Teitge (1986) gave another brief definition: “identity is a definition that transforms a mere biological individual into a human person” (p. 31). To explicate further, identity is how people define themselves via many different expressions such as autobiographical memories (personal identity) and identification with groups (social identity). Social and personal identity are not completely separable but overlap and interact with one another very closely to guide a person’s perceptions, attitudes, and behaviors as well as form a general identity. See the figure below.

We will briefly explore the concept of personal identity before returning to the main concept of social identity.
Personal Identity
Mayer, Greenbaum, Kuenzi, and Shteynberg (2009) state “personal identity consists of moral sensibility and conscience, and also a desire for achievement, mastery, and competence.” Personal identity is the combination of objective biosocial markers such as age, race, sex, and so on, and the personal life history of the individual (Brewer & Gardner, 1996; Weigert et al., 1986). These factors are often considered part of social identity as well because they place the individual into a group. That said, they involve attributes of individuals (even if they are shared within groups characterized by values of those markers), so the biosocial markers also create a personal identity. Personal identity is those aspects of the self that are unique to the individual and are used to define the individual (Brewer & Gardner, 1996).
Social Identity
The most widely accepted definition of social identity comes from Tajfel (1981): “that part of an individual’s self-concept which derives from his [sic] knowledge of his membership in a social group (or groups) together with the value and emotional significance attached with that membership” (p. 255).
According to Tajfel, social identity has three components:
· Self-categorization: Belief of group membership
· Group self-esteem: Importance of group membership to one’s self-concept
· Group commitment: Desire for group membership
Therefore, Tajfel (1981) theorizes that it is not enough to belong to an organization; a person needs to feel connected to the group, and some sort of social-esteem must also be derived from that group membership. When a person categorizes her/himself as part of the group, feels committed to the group, and gains some esteem from the group, then that group has become the person’s in-group. All other groups are potential rivals/competitors for resources and are known as out-groups.
Identity, Threat, and Behavior
There is convincing evidence that under certain conditions, such as various types of group membership and threat conditions, one of the major components of identity is likely to emerge as the primary determinant of behavior (Ellemers et al., 2002; Nario-Redmond, Biernat, Eidelman, & Palenske, 2004). For example, it has been demonstrated that under threat to a high-status group, the behavior of a group member is likely to be determined by her/his social identity (Ellemers et al., 2002; Haslam, O’Brien, & Jetten, Vormedal, & Penna, 2005). In contrast, while under personal threat, the same person’s personal identity is likely to emerge as the primary determinant of behavior (Ellemers et al., 2002; Nario-Redmond et al., 2004). See the table below.
Threat and Behavioral Determinants
THREATENED ENTITIES PRIMARY BEHAVIORAL DETERMINANTS SECONDARY BEHAVIORAL DETERMINANTS
Person Personal identity General identity, social identity
High-status in-group Social identity General identity, personal identity
Group Status and Self-Esteem
Social identity theory explains a person’s behavior in a group using that person’s status within the group as a social comparison. Every group has a certain amount of social status attached to its membership (Morton, Postmes, Haslam, & Hornsey, 2009; Tajfel & Turner, 1979, 1986), which gives it value for the individual who is a member of that particular group. Individual group members use the status from their group membership to gain and maintain self-esteem (Derks, van Laar, & Ellemers, 2009; Morton, Postmes, Haslam, & Hornsey, 2009). Status provides self-esteem for group members because it fulfills the need for a positive social identity (Hogg, 1992; Hogg & Abrams, 1988; 1990; 1993). The motivations to enhance self-esteem and gain status cause individuals to behave in ways that maintain the group and their membership in the group (Derks, van Laar, & Ellemers, 2009; Hogg & Abrams, 1990; Morton, Postmes, Haslam, & Hornsey, 2009). The better one’s own group looks in comparison to other groups, the more status the group gains, and the more self-esteem it can provide for its members (Morton, Postmes, Haslam, & Hornsey, 2009; Tajfel & Turner, 1979, 1986). See the figure below.

Self-esteem is not necessarily the mechanism by which a positive social identity is achieved. Status itself can also be enough to trigger a positive social identity. In this case, individuals seek to join a high-status group to improve their own social identity in general rather than to improve their self-esteem per se (Bettencourt, Dorr, Charlton, & Hume, 2001). But in either case the motivation is a positive social identity from which the person gains benefits (e.g. self-esteem, higher status, possibly power or wealth) through self-identification with the high-status group. The benefits of social identity have recently been demonstrated by Peeters and Oerlemans (2009) who studied two different organizations and found that those with strong social identification with their organization had greater feelings of well-being than those with weaker social identification.
In summary, social identity theory proposes that self-esteem and status are the main reasons that social identity motivates individuals. But remember that a person must also first describe her/himself as part of the group (self-categorization) as well as want to be a part of the group (commitment).
Organizational Applications
Application of social identity theory in organizations is still relatively new (since about the turn of the century). However, because of the success of the theory and the large amounts of empirical evidence, several books have been written (e.g. Haslam, 2004; Hogg & Terry, 2001) that not only synthesize the vast amount of research but also provide many useful tips on how to manage certain aspects of organizations.
The theory has been applied in many different areas of organizations, and it has been used to not only explain why some groups are motivated to experience conflict with groups within their own organization but also why their organization may experience conflict with other organizations. It has also been used to resolve those conflicts or avoid them altogether. Specifically, it has been used to manage group relationships with regards to the following: majority-minority relations, corporate mergers, people with multiple roles in an organization, workgroup socialization, power usage, and leadership, as well as others. Experienced success of organizations in motivating their people through those often difficult tasks reflects the relative easiness of implementation of the theory’s basic components as described in Tajfel’s definition. For instance, during a corporate merger where both organizations have strong corporate identities, leadership in organizations with knowledge of this theory will know that there will be a great resistance to the merger as neither organization will want to give up its social identity. As such, they may want to proceed slowly with the merger and work on creating a shared identity before an official merger occurs so that all involved will be motivated to join the new group. See the figure below. You may have noticed that when corporations merge, a new name may be chosen for the new combined organization.