Journal of Personality and Social Psychology, 67,
Sidanius, J., & Pratto, F. (1999). Social dominance: An
intergroup theory of social hierarchy and oppression.
New York: Cambridge University Press.
Sidanius, J., Pratto, F., & Mitchell, M. (1994). Ingroup
identiﬁcation, social dominance orientation, and
differential intergroup social allocation. Journal of
Social Psychology, 134, 151–167.
Social Identity Theory
Grenoble Ecole de Management and Insper
Institute for Education and Research, Grenoble,
Social Identity Theory (SIT; Tajfel, 1978; Tajfel
& Turner, 1979) begins with the premise that
individuals deﬁne their own identities with regard
to social groups and that such identiﬁcations
work to protect and bolster self-identity. The
creation of group identities involves both the
categorization of one’s “in-group” with regard
to an “out-group” and the tendency to view
one’s own group with a positive bias vis-a-vis
the out-group. The result is an identiﬁcation
with a collective, depersonalized identity based
on group membership and imbued with positive
aspects (e.g., Turner, Hogg, Oakes, Reicher, &
SIT is a classic social psychological theory that
attempts to explain intergroup conﬂict as
a function of group-based self-deﬁnitions.
Intergroup relations; out-group discrimination;
social psychology of groups; group dynamics
SIT grew out of Henri Tajfel’s early work, which
attempted to apply cognitive grouping and gestalt
phenomena to social groups (Hogg & Williams,
2000). Cognitive grouping involves “judgmental
accentuation” where cognitive categories lead to
the increased salience of distinguishing features
between categories, exaggerating category
differences. Applied to social groups, this
principle could be used to explain biased and
exaggerated perceptions of difference between
groups. Tajfel (Tajfel 1970; Tajfel, Flament,
Billig, & Bundy, 1971; Tajfel & Turner, 1979)
used a minimal group paradigm to test this effect.
They divided people into two groups based on
arbitrary criteria and showed that even this “min-
imal” group basis led people to form psycholog-
ical groups, exaggerating the positive qualities of
one’s own group while exaggerating the negative
qualities of the out-group. Subsequent studies
have attempted to demonstrate the wide range
of socially important phenomena that result
from such categorization, such as negative eval-
uations of the out-group (Dovidio, Gaertner, &
Validzic, 1998), stereotyping (Smith, 1999), and
failure to allocate resources to out-group mem-
bers (Sidanius, Pratto, & Mitchell, 1994). How-
ever, more recent research has called into
question whether social identiﬁcation leads to
out-group degradation and tends to emphasize
positive in-group regard more than out-group
degradation (e.g., Reynolds, Turner, & Haslam,
Positive in-group bias can be explained
because the in-group comes to take on a self-
relevant role, where the person deﬁnes him/her-
self through the group. Thus, comparisons
between groups are emotionally laden and equiv-
alent to self-other comparisons, with group
threats interpreted as threats to the self
(Smith, 1999). Turner (1975, p. 10) describe the
Social Identity Theory 1781 S
in-group-out-group relationship as entailing
a “competition for positive identity,” out-group
categorizations strategically framed to maximize
self-evaluations. Thus, treatment of out-group
members is directly related to the motive to
protect or enhance the self (Tajfel & Turner,
Because social identity effects are based on
protection and enhancement of self-concepts,
threat to the self-concept would intuitively be
related to the strongest identity effects. Several
laboratory and ﬁeld studies have empirically con-
ﬁrmed that when groups pose a threat to one
another, the effects of identiﬁcation increase.
For example, negative out-group characteriza-
tions can result from perceptions of out-groups
as competing for resources (e.g., Cooper & Fazio,
1986) and when groups view the out-group as
having a history of tense relations (e.g., Duckitt
& Mphuthing, 1998), a factor which has made
SIT useful in political psychology.
SIT opened up a wide variety of areas for
research, regarding the structure of social identi-
ties, the motivations behind identiﬁcation, the
ﬂuidity between different social identities, and
identity’s effects on individuals, groups, organi-
zations, and wider social collectives. As these
research areas grew, they branched into
a variety of theoretical perspectives, including
self-categorization theory, self-enhancement the-
ory, and self-veriﬁcation theory, among others.
These perspectives do not always agree; for
example, self-veriﬁcation theory (Swann, 1983)
argues that epistemic motives for self-uncertainty
reduction are a primary motive for identiﬁcation
such that people will sustain even negative social
identities if these identities provide epistemic
stability. On the other hand, self-enhancement
theory (e.g., Jones, 1973) holds that individuals
strive for positive selves and will thus discount or
underplay negative self-information. Both of
these theories, although contradictory, can be
interpreted in the light of SIT perspectives, in
which social identity contains both an epistemic
and a positive self-regard component. Subse-
quent research has attempted to tease apart
relative effects of self-enhancement and self-
In addition, the question of social identiﬁca-
tion opened up important research into which
groups people identify with, when they identify
with one group versus another, and how consis-
tent and enduring are such identiﬁcations.
Because a person can be a member of a family,
a neighborhood, a city, a country, etc., simulta-
neously, the groups a person belongs to must be
supplemented with information regarding which
of these groups is cognitively salient at a given
moment and why. A large body of research (e.g.,
Brewer & Gardner, 1996) has attempted to deal
with the multiple social identities that people
inhabit and how they psychologically organize
From a critical psychology perspective, SIT
offers important insights regarding the social
identity bases of discrimination, prejudice, and
intergroup conﬂict, by locating these phenomena
as resulting from group-based categorization and
self-enhancement motives. However, the histori-
cal evolution of the theory itself also offers an
interesting case in which intergroup conﬂicts
become redeﬁned as aspects of individual
identity. As SIT became more focused on self-
veriﬁcation as an epistemic need (e.g., Hogg &
Williams, 2000), rather than self-enhancement as
a motivational driver of identiﬁcation, the
conﬂictual bases of social identity became less
central to the identity literature than the forma-
tion of a stable self-concept. While both of these
bases were apparent in the original theory, critical
scholars may question whether such
a development leaves SIT less able to unpack
the psychological bases of conﬂict and more
focused on an individual psychology of concept
formation. In this respect, SIT may have devel-
oped increasingly in the direction of an individu-
alist cognitive approach at the cost of its
sociological origins. Yet, the diversity of current
approaches using the term “social identity” belies
simply diagnoses, and the story of the theoretical
evolution of the social identity concept is far from
over. This evolution reﬂects wider concerns over
S1782 Social Identity Theory
the role of the “social” in social psychology more
generally, a question which is central to critical
psychologists’ concern to link issues of cogni-
tion, attitude, and emotion with larger social
Brewer, M., & Gardner, W. (1996). Who is this “we”?
Levels of collective identity and self representations.
Journal of Personality and Social Psychology, 71,
Cooper, J., & Fazio, R. H. (1986). The formation and
persistence of attitudes that support intergroup con-
ﬂict. In S. Worchel & W. Austin (Eds.), Psychology
of intergroup relations (pp. 183–195). Chicago: Nel-
Dovidio, J. F., Gaertner, S. L., & Validzic, A. (1998).
Intergroup bias: Status, differentiation, and
a common in-group identity. Journal of Personality
and Social Psychology, 75(1), 109–120.
Duckitt, J., & Mphuthing, T. (1998). Group identiﬁcation
and intergroup attitudes: A longitudinal analysis in
South Africa. Journal of Personality and Social Psy-
chology, 74(1), 80–85.
Hogg, M. A., & Williams, K. D. (2000). From I to We:
social identity and the collective self. Group Dynam-
ics: Theory, Research and Practice, 4(1), 81–97.
Jones, S. C. (1973). Self- and interpersonal evaluations:
Esteem theories versus consistency theories. Psycho-
logical Bulletin, 79, 185–199.
Reynolds, K. J., Turner, J. C., & Haslam, S. A. (2000).
When are we better than them and they worse than us?
A closer look at social discrimination in positive and
negative domains. Journal of Personality and Social
Psychology, 78(1), 64–80.
Sidanius, J., Pratto, F., & Mitchell, M. (1994). Ingroup
identiﬁcation, social dominance orientation, and dif-
ferential intergroup social allocation. Journal of Social
Psychology, 134, 151–167.
Smith, E. R. (1999). Affective and cognitive implications
of a group becoming part of the self: New models of
prejudice and of the self-concept. In D. Abrams &
M. A. Hogg (Eds.), Social identity and social cognition
(pp. 183–196). Oxford, England: Basil Blackwell.
Swann, W. B., Jr. (1983). Self-veriﬁcation: Bringing
social reality into harmony with the self. In J. Suls &
A. G. Greenwald (Eds.), Psychological perspectives
on the self (Vol. 2, pp. 33–66). Hillsdale, NJ: Erlbaum.
Tajfel, H. (1970). Experiments in intergroup discrimina-
tion. Scientiﬁc American, 223, 96–102.
Tajfel, H. (1978). The achievement of inter-group differ-
entiation. In H. Tajfel (Ed.), Differentiation between
social groups (pp. 77–100). London: Academic Press.
Tajfel, H., & Turner, J. C. (1979). An integrative theory of
inter-group conﬂict. In W. G. Austin & S. Worchel
(Eds.), The social psychology of inter-group relations
(pp. 33–47). Monterey, CA: Brooks/Cole.
Tajfel, H., Flament, C., Billig, M., & Bundy, R. (1971).
Social categorization and intergorup behavior.
European Journal of Social Psychology, 1, 149–178.
Turner, J. C. (1975). Social comparison and social iden-
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Social Justice, Overview
Department of Psychology, University of Prince
Edward Island, Charlottetown, PEI, Canada
Human history bears witness to a wide range of
social institutions that have been established in
the name of social justice. One striking feature of
these different institutions is the extent to which
they often diverge from one another. For exam-
ple, while some argue that the cause of social
justice is advanced by ensuring that individuals
are able to engage in unfettered economic
exchange, others view the rise of the calculating
economic agent as the very embodiment of social
injustice. This suggests that the struggle for social
justice ultimately begins in a struggle over the
meaning of justice itself.
At the most basic level, the idea of social justice
highlights the social, political, legal, and institu-
tional arrangements that characterize particular
forms of social organization. One reason why
Social Justice, Overview 1783 S