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CHAPTER TWO
Optimal Distinctiveness Theory:
A Framework for Social Identity,
Social Cognition, and Intergroup
Relations
Geoffrey J. Leonardelli,*Cynthia L. Pickett,
†
and
Marilynn B. Brewer
‡
Contents
1. Introduction 64
2. Optimal Distinctiveness Theory 65
2.1. Basic premises of the optimal distinctiveness model 66
2.2. Some qualifications and clarifications 68
3. Implications for Membership Identification and Preference 70
3.1. Evidence from minority–majority relations 70
3.2. Evidence for a curvilinear relation 75
3.3. Summary of membership identification and preference 77
4. Implications for Social Cognition 77
4.1. Self-concept 78
4.2. Group perception 82
4.3. Social judgments 85
4.4. Summary of social cognition 87
5. Implications for Intergroup Relations 88
5.1. Intergroup behavior in minority–majority relations 88
5.2. Achieving inclusion through intergroup behavior 97
5.3. Achieving distinctiveness through intergroup behavior 99
5.4. Relative strength of different identity needs 100
5.5. Summary of intergroup relations 102
6. Recent Advances and Future Directions 102
6.1. Extending the optimal distinctiveness model 102
6.2. Establishing motivational primacy 104
6.3. The role of social recognition 105
Advances in Experimental Social Psychology, Volume 43 #2010 Elsevier Inc.
ISSN 0065-2601, DOI: 10.1016/S0065-2601(10)43002-6 All rights reserved.
* OB/HRM, Rotman School of Management, University of Toronto, Toronto, Ontario, Canada
{
Department of Psychology, University of California, Davis, California, USA
{
School of Psychology, University of New South Wales, Sydney, New South Wales, Australia
63
7. Conclusion 106
Acknowledgments 107
References 107
Abstract
Optimal distinctiveness theory [Brewer, M. B. (1991). The social self: on being the
same and different at the same time. Personality & Social Psychology Bulletin,
17(5), 475–482] proposes that individuals have two fundamental and competing
human needs—the need for inclusion and the need for differentiation—that can
be met by membershipin moderately inclusive (optimally distinct) groups. In this
chapter, the optimal distinctiveness model and its origins are summarized, and
theoretical extensions and empirical tests of the model are discussed. In particu-
lar, the empirical review summarizes the model’s consequences for social identi-
fication, social cognition, and intergroup relations. The evidence strongly
supports the notion that the needs for inclusion and differentiation influence
self-categorization resulting in a curvilinear relation between group inclusiveness
and group identification. The existing evidence also indicates that the two needs
influence perceptions and judgments of the self and others and the nature of
intragroup and intergroup relations. The chapter concludes by discussing the
interplay of the needs for inclusion and differentiation across levels of the self
and how the needs for inclusion and differentiation influence which level of self
(individual or collective) is motivationally primary.
1. Introduction
A prevalent conception of contemporary western societies is that
society members seek to free themselves from the groups they depend on,
that they strive to pursue personal goals and advance individual careers,
and that they ultimately want to create a world that is a reflection of the
self. Technology is often intended to aid individuals in achieving these
aspirations, and yet, ironically, there are clear instances where the freedom
that technology provides leads individuals to form new groups defined by
that technology. For example, communities have formed around the use
of Apple technology (Kahney, 2004/2006), and these communities not
only exist to promote the advancement and advantages of such technol-
ogy, but become social resources in their own right. They become new
ways of defining group membership and, as such, they return individuals
to the social group.
Our perspective starts with some basic assumptions about the nature of
human sociality, specifically that humans are an obligatorily group-living
species. Over the course of evolution, human adaptations have been such
that individual human beings cannot survive outside of the context of
cooperative, interdependent groups (Brewer, 1997, 2003; Brewer &
64 Geoffrey J. Leonardelli et al.
Caporael, 2006; Caporael, 1997). Cooperative group living not only provides
the benefits of shared resources, division of labor, and mutual protection, but
it also entails costs to individuals who must be willing to give resources and
effort to contribute to group outcomes. Thus, cooperative living requires
both trust (that if I cooperate, others will do their share and reciprocate) and
feelings of obligation (to do one’s own share and reciprocate others’ cooper-
ation). If individuals depend on cooperative intragroup interactions as neces-
sary for personal survival, the question becomes how do individuals
determine who is likely to reciprocate trust, support, and cooperation?
Some groups survive and function better than others. Among other things,
effective cooperation is constrained by group size. On the one hand, groups
that are too small may engage strong obligation but the benefits of shared
resources are limited. The advantage of extending social interdependence and
cooperation to an ever wider circle comes from the ability to exploit resources
across an expanded territory and buffer the effects of temporary depletions or
scarcities in any one local environment. On the other hand, expansion comes
at the cost of increased demands on obligatory sharing and regulation of
reciprocal cooperation. Both the carrying capacity of the environment and
the capacity for distribution of resources, aid, and information inevitably
constrain the potential size of cooperating social networks.
1
Thus, effective
social groups cannot be either too small or too large. To function, social
collectives must be restricted to some optimal size—sufficiently large and
inclusive to realize the advantages of extended cooperation, but sufficiently
exclusive to avoid the disadvantages of spreading social interdependence too
thin. It was this structural requirement for effective group living that formed a
backdrop for the development of optimal distinctiveness theory.
2. Optimal Distinctiveness Theory
Optimal distinctiveness theory was developed to fill a gap in extant
theories of social identity. The original statements of social identity theory
(Tajfel, 1981) and the subsequent development of self-categorization
theory (Turner et al., 1987) were based heavily on cognitive processes of
1
British explorer Percy H. Fawcett, known for his early twentieth century explorations into the
South American jungles of the Amazon, was well aware of such tradeoffs. Faced with a variety of
threats—such as malaria, anacondas, hostile Indians, and starvation—it might be natural for an Amazonian
explorer to practice ‘‘safety in numbers,’’ but such efforts could make matters worse. Fawcett preferred to
keep his expedition small, as it would be more capable of living off the land and would simultaneously pose
no threat to Indians (Grann, 2009). Moreover, in an event that serves as a reminder of the dangers of the
Amazon and the disadvantages of overly inclusive groups, Fawcett had been told of an 80-person party that
had to retire from its exploration because so many members were picked off and killed by poison arrows
(Grann, 2009).
Optimal Distinctiveness Theory 65
categorization and perceptual accentuation. This depiction provided an
explanation for why and how specific social categorizations and in-group–
out-group distinctions become salient but it lacked a driver for the process
of identification with in-groups, particularly for chronic, long-term identifi-
cation. Although the theory postulated that social identity salience had
motivational consequences in the form of a striving for positive distinctiveness
of the in-group (Tajfel & Turner, 1979), a motivational component was
missing from the theory with respect to antecedents of social identity.
For many social psychologists, the idea that social identification—with
all its significant emotional and behavioral concomitants—is based solely on
‘‘cold cognition’’ was intuitively incomplete. Because group identity some-
times entails self-sacrifice in the interests of group welfare and solidarity,
understanding why and when individuals are willing to relegate their sense
of self to significant group identities requires motivational as well as cogni-
tive analysis. Motivational explanations were also needed to account for
why group membership does not always lead to identification and why
individuals are more chronically identified with some in-groups rather than
others.
2.1. Basic premises of the optimal distinctiveness model
We start from the assumption that the requirements of group living have
shaped the evolution of human psychology. More specifically, if social
differentiation and intergroup boundaries are functional for social coopera-
tion, and social cooperation is essential for human survival, then there
should be psychological mechanisms at the individual level that motivate
and sustain in-group identification and differentiation.
The optimal distinctiveness model (Brewer, 1991) posits that human
beings are characterized by two opposing needs that govern the relationship
between the self-concept and membership in social groups. The first is a
need for assimilation and inclusion, a desire for belonging that motivates
immersion in social groups. The second is a need for differentiation from
others that operates in opposition to the need for immersion. As group
membership becomes more and more inclusive, the need for inclusion is
satisfied but the need for differentiation is activated; conversely, as inclu-
siveness decreases, the differentiation need is reduced but the need for
inclusion is activated. These competing drives hold each other in check,
assuring that interests at one level are not consistently sacrificed to interests
at the other. According to the model, the two opposing motives produce an
emergent characteristic—the capacity for social identification with distinc-
tive groups that satisfy both needs simultaneously.
The basic premise of the optimal distinctiveness model is that the two
identity needs (inclusion/assimilation and differentiation/distinctiveness)
are independent and work in opposition to motivate group identification.
66 Geoffrey J. Leonardelli et al.
More specifically, it is proposed that social identities are selected and
activated to the extent that they help to achieve a balance between needs
for inclusion and for differentiation in a given social context. Optimal
identities are those that satisfy the need for inclusion within the in-group
and simultaneously serve the need for differentiation through distinctions
between the in-group and out-group. In the original statement of the theory,
Brewer (1991) tried to capture the essential ideas in the form of a figure that
depicted the opposing drives and the point of equilibrium (Fig. 2.1, adapted
from Brewer, 1991).
Researchers widely consider the inclusion need, the differentiation
need, or both fundamental to self and identity (Baumeister & Leary, 1995;
Fiske, 2004; Maslow, 1943; Vignoles et al., 2006), and the idea that
individuals prefer a balance between their needs for inclusion and differen-
tiation is not novel. Rather, this notion is the basis for uniqueness theory
(Snyder & Fromkin, 1980) as well as a number of theories on individuation
(e.g., Codol, 1975; Lemaine, 1974; Maslach, 1974; Ziller, 1964) where the
needs for inclusion and distinctiveness are met by comparisons with other
individuals. Optimal distinctiveness theory differs from the other motiva-
tional theories in that the balance between inclusion and differentiation is
achieved at the group level, through identification with groups that are both
sufficiently inclusive and sufficiently distinct to meet both needs
simultaneously.
Assimilation
Need (dissatisfaction)
Differentiation
Resultant
satisfaction
Optimal
Low Inclusion High
Figure 2.1 Optimal distinctiveness theory: Opposing process model. Reprinted with
permission from Brewer (1991). Copyright, Sage/Society of Personality and Social
Psychology.
Optimal Distinctiveness Theory 67
In effect, optimal social identities involve shared distinctiveness (Brewer &
Silver, 2000; Stapel & Marx, 2007). Individuals will resist being identified
with social categorizations that are either too inclusive or too differentiating
but will define themselves in terms of social identities that are optimally
distinctive. Equilibrium is maintained by correcting for deviations from
optimality. A situation in which a person is overly individuated will excite
the need for inclusion, motivating the person to adopt a more inclusive
social identity. Conversely, situations that arouse feelings of deindividuation
will activate the need for differentiation, resulting in a search for more
exclusive or distinct identities.
2.2. Some qualifications and clarifications
Although hypotheses derived from optimal distinctiveness theory have been
tested by different researchers in different contexts, some aspects of the
theory are frequently misunderstood. Importantly, the model does not
postulate that optimal distinctiveness is a property of some groups rather
than others and that individuals directly seek identification with such
optimal groups. Rather, optimality is a product of current levels of activa-
tion of the opposing motives for inclusion and differentiation and group
properties that determine its level of inclusiveness and distinctiveness. This
leads to three principles that are essential to understanding optimal
distinctiveness.
First, optimal distinctiveness is context specific. Context affects both the
activation of motives or needs and the relative distinctiveness of specific
social categories. For example, in the context of an international psychology
conference, group identity as a psychologist is inclusive but not optimally
distinctive. In this context, shared identity as a social psychologist is both
sufficiently inclusive and differentiating. However, at a university faculty
meeting, group identity as a psychologist is both inclusive and distinctive,
and any subdisciplinary group membership would be excessively
differentiating.
Second, optimal distinctiveness is a dynamic equilibrium. Even within a given
context, optimality is not necessarily fixed because inclusion and differenti-
ation motives are also subject to temporal influences and change over time.
For example, when an individual first joins a new social group, inclusion
and assimilation needs are likely to be particularly salient. At this stage, the
new group member will be concerned that the in-group is sufficiently
inclusive and broadly defined that he/she clearly falls within the group
boundaries. Over time, however, when inclusion has been sufficiently
established, differentiation motives are more likely to be activated and
group members become more concerned that the in-group boundaries
are defined so that the in-group can be clearly differentiated within its social
context.
68 Geoffrey J. Leonardelli et al.
Third, identity motives vary across situation, culture, and individuals. Asking
‘‘how ‘strong’ an individual’s inclusion motive is’’ is like asking how strong
the individual’s hunger motivation is. Like any need or drive, inclusion and
differentiation motives vary as a function of current levels of satiation or
deprivation. However, individuals may differ in how sensitive they are to
changes in levels of inclusiveness. Just as some individuals start feeling
ravenously hungry after an hour or two since they last ate, whereas other
individuals do not even notice they have not eaten all day, so some people
will react strongly to a slight loss of inclusiveness (or slight expansion of
group boundaries), whereas others will be more tolerant of a range of
in-group inclusiveness.
Put more formally, the model as depicted in Fig. 2.1 has four important
parameters—the height (intercept) of the need for differentiation, the
height (intercept) of the need for inclusion, the negative slope of the need
for inclusion, and the positive slope of the need for differentiation. Of these
four, one is presumed to be fixed. The intercept (zero activation) of the
need for differentiation is assumed to be at the point of complete individu-
ation (the endpoint of the inclusiveness dimension). All of the other para-
meters are free to vary; any changes in the intercept or slope of the inclusion
drive or the slope of the differentiation drive will alter the point of equilib-
rium that represents an optimal identity. Thus, the model depicted in
Fig. 2.1 is just one member of a class of models containing all possible
variations in these parameters, and differences across situations, cultures, and
individuals can be represented in terms of variation in the slopes of the two
drives (which can vary independently). (See Brewer and Roccas (2001) for a
discussion of how cultural differences can be reflected in model parameters
and the point of equilibrium.) Again, the overall point is to emphasize that
optimal distinctiveness is not a fixed property of groups or of individuals but
a consequence of motivational dynamics at both levels.
Another important clarification is that although perceived intragroup
inclusion and perceived intragroup differentiation are necessarily opposi-
tional (see Fig. 2.1), the extent to which groups are able to meet group
members’ needs for inclusion and differentiation may actually be positively
related. As noted previously, the need for inclusion is met through assimila-
tion within the group (intragroup inclusion), whereas the need for differ-
entiation is met through comparisons between groups (intergroup
differentiation). Thus, it is possible for groups to be high on both dimen-
sions, and indeed, to the extent that individuals pursue membership in
optimally distinct groups in order to be both included and distinctive,
then evidence should indicate that greater perceived intergroup differentia-
tion is positively associated with greater perceived intragroup inclusion.
To examine this hypothesis, Leonardelli and Pickett (2009) constructed
measures designed to assess the degree to which individuals perceive that
a particular group identity confers intragroup inclusion and intragroup
Optimal Distinctiveness Theory 69
differentiation. Undergraduates were asked to rate the degree to which
students within their university were similar to each other (a form of
intragroup inclusion) and the extent to which students are different from
each other. Analysis revealed that these perceptions were negatively related
to each other; not surprisingly, perceived intragroup inclusion was nega-
tively correlated with perceived intragroup differentiation, r¼0.33.
However, participants were also asked to indicate the extent to which
their university is different from other universities—a measure of intergroup
differentiation. Results of a correlational analysis indicated that there was no
negative association between intragroup inclusion and intergroup differen-
tiation, r¼0.05. Moreover, when controlling for feelings of intragroup
differentiation, the association between intragroup inclusion and intergroup
differentiation was significant and positive, pr ¼0.21. This finding provides
initial evidence for a positive relation between the degree to which a group
is able to meet group members’ needs for inclusion and differentiation.
In sum, the theory stipulates that individuals are motivated by two
fundamental and competing human needs, and that individuals can simul-
taneously meet these needs by identifying with moderately inclusive group
memberships. Such group memberships meet the need for inclusion within
the group and the need for differentiation between groups. Furthermore,
although the needs are necessarily oppositional, the extent to which groups
are able to meet group members’ needs for inclusion and differentiation may
actually be positively related when inclusion is met within and differentia-
tion is met between groups.
3. Implications for Membership Identification
and Preference
Optimal distinctiveness theory helps to explain existing evidence in
ways not previously offered or addressed by theories on self-categorization,
social identity, and uncertainty identity (Hogg, 2007). As one case, it offers
an explanation for the psychology of minority–majority relations, or per-
haps more generally, it offers a theoretical rationale for why group inclu-
siveness—as defined by relative in-group size—yields an inverted U-shaped
curvilinear effect on group identification. Each of these features is addressed
in turn.
3.1. Evidence from minority–majority relations
Minority–majority relations are defined by relative rather than absolute in-
group size. Whereas absolute size refers to the number of group members,
relative size is contextual. A group of 500 is a numerical majority in a social
70 Geoffrey J. Leonardelli et al.
context of 600, but a numerical minority in a social context of 6000.
Relative in-group size is one way to conceptualize group inclusiveness,
where majority groups are considered highly inclusive groups compared
to more moderately inclusive minority groups. Just as being a psychologist is
not distinctive in the context of a psychology convention, right-handedness
is not distinctive in a world in which the vast majority of people are right-
handed.
According to optimal distinctiveness theory (Brewer, 1991), individuals
are motivated to prefer membership in salient numerical minorities because
such groups meet the needs for inclusion and differentiation. Whereas
numerical majorities meet the need for inclusion because of their large
size, they lack distinctiveness within the social context. Numerical mino-
rities, however, typically meet both needs: the shared identity meets the
need for inclusion, and their relatively small size makes the in-group distinct
from larger groups. Individuals should thus be more likely to identify with
and prefer membership in numerical minorities because these groups are
optimally distinct.
Evidence from a variety of studies supports the idea that numerical
minorities are perceived to be optimally distinct. On the distinctiveness
front, memberships in numerical minorities are recalled more spontaneously
as they contribute a sense of distinctiveness to self-definition (McGuire &
McGuire, 1988) and lead group members to describe themselves by the
characteristics that typify their group (Simon & Hamilton, 1994). On the
inclusion front, members of minorities are more likely to consider them-
selves typical of their group (e.g., Ellemers et al., 1999), and minority groups
are perceived to be more homogeneous (e.g., Simon & Brown, 1987),
more like an entitative unit (Mullen, 1991), and their members perceived as
more similar to each other (Nelson & Miller, 1995) than majority groups.
According to optimal distinctiveness theory, if individuals perceive
minority groups to be distinctive and inclusive, then individuals should be
more likely to identify with and prefer minority to majority group mem-
bership. This prediction is also supported by a good deal of evidence
on group members’ identification with and evaluations of minority and
majority groups. Specifically, members of numerical minorities are more
likely to identify with their group than are members of numerical majorities
(e.g., Blanz et al., 1995; Ellemers & Van Rijswijk, 1997; Ellemers et al.,
1999; Feather, 1995; Lu
¨cken & Simon, 2005; Simon & Brown, 1987;
Simon & Hamilton, 1994, Experiment 1). This effect has been demon-
strated with laboratory-created and real groups using a variety of measures
of collective identification.
Relatedly, the literature on in-group favoritism—group members’ pref-
erential treatment for their own group over other groups—also suggests that
minority group members are more identified with or attached to their in-
groups than are members of majority groups. Research on in-group
Optimal Distinctiveness Theory 71
favoritism (also called in-group bias; for a review, see Hewstone et al., 2002)
consistently reveals that members of minority groups spontaneously
exhibit greater in-group favoritism than members of majority groups do
(Gerard & Hoyt, 1974; for a meta-analysis, see Mullen et al., 1992; see also
Bettencourt et al., 1999; Brewer et al., 1993; Leonardelli, 1998; Leonardelli
& Brewer, 2001).
One frequent source of confusion is the notion that group members’
greater identification with minority groups could be explained by self-
categorization theory’s meta-contrast ratio (Turner et al., 1987). According
to self-categorization theory, individuals will perceive themselves to be
members of a social category when, in a given context, the ratio of
between-group differences to within-group differentiation is greater than
one. Because it focuses on a specific intergroup comparison, however, the
meta-contrast ratio does not offer an explanation for asymmetries of social
identification within a given intergroup context—why one group would be
more salient or differentiated within that context than another, and why
members of one group would identify more strongly with their group than
members of another group. The difference between being right- and left-
handed meets the meta-contrast principle for intergroup differentiation on
the handedness dimension, but left-handed people are more likely to form a
meaningful shared group identity than right-handed people. By focusing on
relative distinctiveness within the overall group context, optimal distinc-
tiveness theory can account for this asymmetry.
Additional tests have directly investigated the effects of relative size on
group identification and in-group favoritism from the perspective of opti-
mal distinctiveness theory. Abrams (1994a) found that young adults exhib-
ited greater commitment and similarity to their political parties when these
parties were in the minority; that is, even in domains where it is more of a
political asset to be in the numerical majority, members of minority political
parties were more committed to their group membership. Also, Leonardelli
and Brewer (2001) distinguished between the more cognitive and evalua-
tive components of collective identity, defining the more evaluative com-
ponent as ‘‘in-group satisfaction,’’ where group members rated their level of
satisfaction with their group. They found that, at least when group members
were induced to see themselves as typical group members, minority group
members reported greater satisfaction with their group than did majority
group members (Studies 2 and 3).
These data are supportive of the notion that individuals like membership
in minority groups, presumably, because these groups are optimally distinct.
To make stronger inferences about membership preference, however, it is
necessary to determine whether individuals actually prefer membership in
minority over majority group memberships when given a choice. The
accumulated evidence in minority–majority relations, which reveals that
numerical minorities are more likely to spontaneously exhibit in-group
72 Geoffrey J. Leonardelli et al.
favoritism than are members of numerical majorities (e.g., Mullen et al.,
1992), has been interpreted in different ways, either as support for minority
membership preference (Leonardelli & Brewer, 2001) or as a means to
compensate for insecure group membership (Sachdev & Bourhis, 1984).
Put another way, the question remains whether minority group members
exhibit in-group favoritism because they prefer minority to majority groups
memberships or because they cannot be a member of the majority group.
To properly infer membership preference, we needed a paradigm where
individuals already belong to or are capable of joining a numerical minority
and a majority group and can choose between them (Leonardelli, 2002,
2006). The benefits of such a paradigm are twofold. First, it directly assesses
membership preferences by allowing comparative evaluations between
groups to which membership is accessible. Second, and perhaps most
importantly, this paradigm reduces the likelihood of defensive, compensa-
tory, or dissonance-reducing responses as members who may have been
motivated to compensate for minority group membership would no longer
need to do so as they have access to the more secure, more powerful
numerical majority.
A series of studies tested membership preferences for minority and
majority groups (Leonardelli, 2006). In one study, undergraduate research
participants were first classified into two groups using two classic minimal
group categorization schemes: the painting preference and dot estimation
tasks (Tajfel et al., 1971). For the painting preference task, participants
chose which of two paintings they preferred on a series of 10 trials, were
all told the task classified people into one of two categories (Kandinsky or
Klee painting preference groups), and ostensibly based on their responses,
all were then classified as members of the Kandinsky group. Some parti-
cipants read that their category was a numerical minority whereas others
read that it was the majority. Participants then completed a dot estimation
task where they estimated the number of dots on a series of 10 screens,
were told that their estimates were used to classify people as ‘‘global
perceivers’’ or ‘‘detailed perceivers,’’ and ostensibly based on their
responses, all were placed into the global perceiver group. The reported
size of this category depended on the size of the Kandinsky group: those
in a Kandinsky minority were assigned to a global perceiver majority,
whereas those in a Kandinsky majority were assigned to a global perceiver
minority.
Thus, all participants were classified into both the Kandinsky and global
perceiver groups; that is, all were placed into two groups, one a numerical
minority and one a majority. Size was counterbalanced with category label
to control for individuals’ preferences for different tasks or group labels. To
control for any order effects that category assignment may have caused, half
of the participants completed the painting preference task first, and the other
half completed the dot estimation task first.
Optimal Distinctiveness Theory 73
Participants then completed an assessment of membership preference, a
dichotomous choice measure where they were asked to ‘‘choose which
group you would like to represent’’ for an upcoming social interaction task
where they would be interacting with other members of the selected group.
Furthermore, all participants were discouraged from selecting group mem-
bership based on the perceived need for a specific group to be represented.
They were told that sufficient numbers of members from each group had
already chosen to represent them, so that the participant should select to
represent the group that they preferred more.
A second seven-point measure of membership preference was also
included to test membership preferences where a no-preference rating
option was available to participants and they rated which group membership
they preferred more; this measure was recoded to range from 3toþ3,
where greater positive numbers indicated greater minority membership
preference and greater negative numbers indicated greater majority mem-
bership preference. Analysis on the overall sample revealed that most
participants selected the minority (69/89 ¼78%), and a w
2
test yielded a
significant difference from the no preference percentage (50%). Consistent
with choice responses, ratings on the more continuous measure also indi-
cated a general membership preference for numerical minorities
(M¼0.71, SD ¼1.21), a mean significantly different from zero, the
point of no preference. Regardless of category label and classification
order, individuals preferred numerical minorities.
Consistent with the evidence on relative size and group identification,
these effects strongly support the notion that individuals actually prefer
membership in numerical minorities, but it is still possible that minority
membership preference resulted from the fact that individuals were also
classified as members of the numerical majority, which gave group members
a sense of security and allowed them to identify with the smaller group
membership. In order to rule out this alternative, another study
(Leonardelli, 2006) investigated membership preferences when individuals
were faced with the opportunity to join a numerical minority or majority
group. As part of a classroom exercise, undergraduates were instructed that
their class would be split into two groups, Groups A and B, and that they
were to decide which of the two groups they would like to represent; no
other details were given about the task. About half were told that Group A
was smaller, whereas the rest were told that Group B was smaller. Partici-
pants then decided which of the two groups they would represent for a class
demonstration and again completed a seven-point measure of membership
preference. Consistent with the previous study, 79% (23/29) selected the
numerical minority, a frequency significantly different from 50%, and
minority membership preference was also evident on the continuous mea-
sure (M¼1.28, SD ¼1.25), a mean significantly different from zero. The
accumulated data—whether collected with measures of group identification,
74 Geoffrey J. Leonardelli et al.
in-group favoritism, or membership choice or preference—thus point to a
membership preference for numerical minorities, consistent with optimal
distinctiveness theory.
3.2. Evidence for a curvilinear relation
Minority group members identify more with their group than majority
group members do, and this effect reflects one part of a more general
curvilinear prediction made by optimal distinctiveness theory: individuals
should be most likely to identify with and prefer moderately inclusive rather
than extremely inclusive or exclusive groups. In essence, an inverted ‘‘U’’
relationship is expected between group inclusiveness and group identifica-
tion. Evidence just reported from the studies of minority–majority relations
yields insight into the second half of this prediction, namely between
comparisons of moderately inclusive and extremely inclusive in-groups.
Additional evidence testing a more complete range of group inclusiveness
also supports this prediction.
In one study, Lau (1989) used data from the U.S. National Election
Studies of 1972 and 1976 to assess the degree of group identification of
African-American respondents as a function of social density—the propor-
tion of fellow group members in the immediate environment. Consistent
with optimal distinctiveness theory, Lau predicted that there would be a
curvilinear (inverted U-shaped) relation between residential density and the
respondents’ felt closeness to blacks as a social group. In areas of the country
where the number of African-Americans is relatively low, increased num-
bers should be associated with increased group identification, but where
social density is relatively high, increased numbers of blacks in the immedi-
ate environment should be associated with decreases in group identification
as the salience of blacks as a distinctive social category decreases.
Operationalizing social density as the proportion of black residents in the
same census tract as the respondent, Lau (1989) found the predicted curvi-
linear relationship between density and probability of feeling close to blacks.
Black respondents who lived in areas where 40–70% of the residents were
black were significantly more likely to identify themselves as ‘‘particularly
close’’ to blacks as a social group than were those who lived in highly
segregated census tracts or ones where there were few other black residents.
In another study, Bearman and Bru
¨ckner (2001) investigated adoles-
cents’ commitment to public virginity pledges, where individuals make a
public commitment to abstaining from sex until marriage. Such virginity
pledges greatly delay adolescents’ transition to first intercourse, but of
particular interest here is high school girls’ willingness to pledge in the
first place. The researchers found that their respondents’ willingness to
pledge was in part a function of the percentage of same sex respondents at
their high school who had already pledged. Bearman and Bru
¨ckner found
Optimal Distinctiveness Theory 75
that likelihood to commit to a virginity pledge increased as the percentage
of respondents increased until 40% of respondents had committed to such
pledges; after that, respondents became less likely to pledge as percentage of
pledged respondents continued to increase. Joining a community of ‘‘pled-
gers’’ depended at least in part on the relative size of those already pledging,
and the effect of group size was curvilinearly related to willingness to join.
Abrams (2009, Study 1) conducted a direct empirical test of the curvi-
linear prediction made by optimal distinctiveness theory between group
inclusiveness and group identification in a field test investigating young
adults’ music preferences. In this study, music preferences could range from
widely inclusive (such as pop/rock or disco/dance, which were classified as
‘‘superordinate’’) to increasingly more exclusive forms of pop or rock music
(which were respectively labeled ‘‘intermediate,’’ ‘‘subordinate,’’ and
‘‘minority’’), to those preferences that could not be classified as pop or
rock music (‘‘non-rock’’). Abrams demonstrated an inverse U-shaped pat-
tern, where those with moderately exclusive music preferences (‘‘subordi-
nate’’ group) reported the greatest degree of behavioral identification
(through listening to the music and active involvement) and those with
extremely inclusive or exclusive preferences (the ‘‘superordinate’’ and
‘‘non-rock’’ categories, respectively) reported the lowest levels of listening
and active involvement.
Referring back to Fig. 2.1, a moderate level of group inclusiveness is
expected to yield greater group identification because such moderately
inclusive groups simultaneously meet the needs for inclusion and differen-
tiation. Some additional studies have helped to identify the role that the
inclusion and differentiation needs play in the connection between group
inclusiveness (as indexed by group size) and group identification. On the
one hand, group inclusiveness is expected to satisfy the needs for inclusion
and differentiation linearly, albeit with positive and negative associations,
respectively. Some evidence has illustrated this connection; Pickett et al.
(2002b, Study 1) found that experimentally arousing the need for inclusion
(by having participants recall a time when they had felt excessively different)
led group members to consider more inclusive social categories as more
important to their identity compared to when a need for differentiation had
been induced (by recalling a time when they felt too much like everyone
else around them). (For a similar test, see also Sorrentino et al. (2007); the
authors arrived at similar conclusions to those drawn by Pickett and collea-
gues although they argue that the effects of the need state manipulation are
more likely to be evident among individuals with high certainty
orientation.)
According to optimal distinctiveness theory, group members will iden-
tify most strongly with groups that are neither too differentiated nor too
inclusive. That is, the extent to which a group meets either need should also
have a curvilinear relation with group identification. Research by Badea
76 Geoffrey J. Leonardelli et al.
et al. (in press) tested this hypothesis. In their Study 1, undergraduates
completed a measure of optimal distinctiveness (Pickett et al., 2002a,b)—
where increasing scores indicated a desire for inclusion and to increase
group size, whereas decreasing scores indicated a desire for differentiation
and to decrease group size—and a measure of group identification with
their university faculty (students in this study were part of the physics or law
faculties). Analysis yielded an inverted U-shaped relation, where high and
low scores on the optimal distinctiveness measure indicated lower group
identification than those who scored in the middle of the scale. Two
additional experiments that manipulated in-group size using minimal
groups confirmed these relations when group identification and optimal
distinctiveness were assessed under nonthreat conditions. This research
lends clear support to the notion that the curvilinear relation between
group size and identification is a function of optimal distinctiveness motives.
3.3. Summary of membership identification and preference
In sum, optimal distinctiveness theory makes sense of and interprets existing
data on determinants of in-group identification. First, the accumulated
evidence strongly points to a preference for minority group memberships
based on evidence collected with different types of groups (laboratory-
created and natural), with different operations of relative size, and with
different dependent measures (collective identification, in-group favoritism,
membership choice, membership preference). Second, the evidence indi-
cates that the predicted curvilinear relation between group inclusiveness and
group identification occurs across different types of membership groups
(race, virginity pledgers, music preferences) and with different operations
of inclusiveness (social density, relative size, optimal distinctiveness need
satisfaction).
4. Implications for Social Cognition
Similar to other motivational states, activation of the needs for inclu-
sion and differentiation can instigate a range of behavioral and cognitive
responses. The previous section focused on the relation between the needs
for inclusion and differentiation and levels of group identification. How-
ever, research has demonstrated that need arousal can influence not only the
groups with which people choose to identify but also how people perceive
themselves as group members, how they perceive their groups, and the
types of intragroup and intergroup judgments that are made. Of impor-
tance, this research highlights the flexibility and range of reactions that
individuals exhibit in response to heightened inclusion and differentiation
Optimal Distinctiveness Theory 77
needs, and suggests that the needs influence both relatively low-level
cognitions as well as higher-order cognitive judgments. In the next section,
the implications of optimal distinctiveness theory for social cognition are
discussed.
4.1. Self-concept
The self-concept is characterized by both malleability and stability, and the
content of people’s self-concepts has been shown to vary as a function of the
social context and individuals’ motivational states (e.g., Markus & Kunda,
1986). In a classic demonstration, Markus and Kunda (1986) found that the
desire to see the self as unique led to heightened accessibility of concepts
related to difference from others, whereas the desire to see oneself as similar
to others led to heightened accessibility of concepts related to similarity.
Self-concept changes have also been demonstrated in response to self-
threats. For example, mortality salience has been shown to heighten the
clarity and coherence of the self-concept, particularly among individuals
who value structured self-knowledge (Landau et al., 2009). Similar to how
other motivations shape how perceivers view themselves, the needs for
inclusion and differentiation can also bring about important self-concept
changes.
A key tenet of self-categorization theory is that categorization of the self
as a group member entails a shift from defining the self in terms of idiosyn-
cratic traits to defining the self in terms of the traits and attributes that are
prototypic of the group (Turner et al., 1987). Although all group members
are presumed to engage in this perceptual shift as part of the categorization
process, individuals can vary in their prototypicality. A prototypical group
member is someone who embodies the central features and attributes of a
social category. More specifically, ‘‘the more a group member differs from
out-group members and the less he or she differs from other in-group
members ... the more that individual will be perceived as prototypical of
the group’’ (Oakes et al., 1998, p. 80).
Prototypical group members tend to occupy secure positions within the
group and generally experience feelings of high in-group inclusion (Oakes
et al., 1998). Thus, one way that individuals can satisfy the need for in-
group inclusion is to alter the self to be more consistent with the group
prototype. Altering the self to be more consistent with the group prototype
can be achieved in a variety of ways. For example, group members can
change their behavior or appearance or adopt the beliefs and attitudes that
are typical of the group. Prototypicality can also be achieved by perceiving
the traits that are stereotypical of the group as being descriptive of the self.
This process has been described in the research literature as self-stereotyping
(e.g., Brown & Turner, 1981; Hogg & Turner, 1987).
78 Geoffrey J. Leonardelli et al.
Because prototypicality involves both a shift toward the in-group pro-
totype and a shift away from the out-group prototype, heightened proto-
typicality can also serve the need for differentiation. Individuals who are
already highly identified with a specific group membership are particularly
likely to seek enhanced prototypicality with that group in response to
threats to inclusiveness or differentiation.
A series of studies was conducted by Pickett et al. (2002a) to demonstrate
that arousing either the need for inclusion or the need for differentiation can
result in compensatory self-concept changes. Specifically, need arousal was
hypothesized to lead to increased levels of self-stereotyping. In three studies,
Pickett et al. (2002a,b) experimentally manipulated participants’ need for
inclusion by telling participants that their score on a personality test was very
discrepant from the typical or average score of other in-group members.
Participants in the need for differentiation condition were told that their
personal score was close to the in-group mean, but that the personality
distribution of the in-group overlapped highly with that of a relevant out-
group (i.e., the in-group was not distinctive). Control participants were told
that their personal score was quite close to the in-group mean and that very
little overlap existed between the in-group and out-group personality dis-
tributions. Participants received this information in both verbal and graphi-
cal forms (see Fig. 2.2). Participants were then provided with a list of traits
and embedded in this list were traits that had been pretested as being
stereotypical of the in-group as well as traits that had been shown in
pretesting to be stereotype-irrelevant.
It was predicted that participants in both the need for inclusion and the
need for differentiation conditions would rate the stereotype-relevant traits
as being more descriptive of themselves—that is, they would engage in
greater self-stereotyping—compared to control participants. Support was
found for this prediction across the three studies. That is, when participants
were told that their personality score indicated that they were quite different
from other members of the in-group (the need for inclusion condition),
they compensated by perceiving stereotypical in-group traits (but not
stereotype-irrelevant traits) as being more descriptive of the self. The same
effect also occurred for participants who had been told that considerable
overlap exists between the in-group and out-group distributions (the need
for differentiation condition). These participants also engaged in greater
self-stereotyping.
The third study of this paper indicated that these self-stereotyping effects
may have both private and public components. In this study, participants
were asked to describe themselves verbally to a hypothetical in-group
member (the in-group for this study was sorority members), and these
descriptions were videotaped and coded for stereotypicality—that is, the
extent to which the sorority member appeared to be social,outgoing,snobby,
and superficial. These videos were also coded on a set of stereotype-irrelevant
Optimal Distinctiveness Theory 79
traits—mature,funny, and hostile. Highly identified group members in the
need for inclusion and the need for differentiation conditions presented
themselves in a more stereotypical fashion compared to control participants.
These data suggest that people respond to marginal in-group status or high
intergroup similarity by changing both how they perceive the self and how
they present the self to others.
Other researchers have demonstrated parallel effects of threats to inclusion
or differentiation on individuals’ self-perceptions. Moons et al. (2009)
threatened in-group inclusion using a manipulation adapted from Pickett
et al. (2002a,b). Participants in the threat condition were told that their
performance on a personality measure indicates that they are quite different
from other in-group members. Participants in the no-threat condition
received no feedback about where they stood in relation to other group
members. All participants were given information about the average level
of two emotions (anger and happiness) exhibited by in-group members
and were then asked to indicate the degree to which they themselves experi-
ence those emotions. Results of the study demonstrated greater emotional
59
Need for inclusion condition
Control condition
Need for differentiation
Out-group In-group
Out-group
Out-group
In-group
In-group
56
59
59
29
29
Figure 2.2 Graphical representation of the personality score feedback used to manip-
ulate identity motives (Pickett et al., 2002a). The dashed line represents the score that
the individual participant received in each of the three conditions.
80 Geoffrey J. Leonardelli et al.
convergence under conditions of inclusion threat, indicating that the process
of self-stereotyping can extend beyond traits to actual emotional experiences.
In a similar vein, Spears et al. (1997) threatened the distinctiveness of parti-
cipants’ in-group (psychology students) by telling participants that psychol-
ogy students are quite similar to business students. Under these conditions,
highly identified group members tended to see themselves as more similar to
the average psychology student (i.e., they engaged in self-stereotyping).
In addition to producing effects on trait and emotional self-stereotyping,
the needs for inclusion or differentiation can also lead to other self-concept
changes that bring the individual closer to the group. For example, Burris
and Jackson (2000) gave participants who were either high or low on a
measure of intrinsic religious orientation—the extent to which a person is
devoutly committed to religion as an end in itself—false feedback that either
threatened or bolstered their self-perceptions on a dimension that was
important to religious group membership (helpfulness). Participants in the
threat condition were specifically told that compared to other group mem-
bers, they ranked lower in helpfulness than they actually perceived them-
selves to rank (as indicated by their pretest scores). This feedback suggested
to participants that they may not embody a characteristic that is important to
in-group inclusion. Participants who were high in intrinsic religious orien-
tation (i.e., those for whom religious group membership was very impor-
tant) responded to threat by showing a significant increase in how identified
they were with the group and how good and worthy they felt as group
members, as evidenced by their scores on specific collective self-esteem
items (Luhtanen & Crocker, 1992). When the group membership was
important, threats to the participants’ standing in the group led to the
compensatory response of perceiving the self as being an even better
group member. Thus, another way that group members can cope with
threats to in-group inclusion is by exaggerating their self-conceptions as
good, worthy in-group members.
The research literature on newcomers to groups also suggests that
insecurity about one’s standing within a group can lead to changes in the
self. According to Moreland and Levine’s group socialization model
(Moreland & Levine, 1982, 2002), new group members engage in an active
process of socialization where there are attempts by both the new member
and the group to achieve closer self-group alignment. For example, new
group members are more likely to behave in role-congruent ways, monitor
the behavior and outcomes of other group members, and seek feedback
from other group members about their own behavior (Moreland et al.,
2001). Because new group members have not been fully accepted by
existing group members, new group members often feel that their inclusion
within the group is not secure and that they must assimilate to the group in
order to avoid expulsion. This process of socialization can result in signifi-
cant changes in the self-concept of new group members.
Optimal Distinctiveness Theory 81
4.2. Group perception
One conclusion that may be drawn from the previous section is that
changing the self to be more prototypical (to the extent that this is possible)
is one means of mitigating threats to inclusion and distinctiveness. How-
ever, changing the self is not the only option available for achieving greater
in-group inclusion and intergroup distinctiveness. Another way of estab-
lishing in-group inclusion and enhancing group distinctiveness is mentally
altering how one perceives the in-group and the out-group. Enhancement
of both in-group and out-group homogeneity simultaneously increases
intergroup contrast and reinforces inclusion within the in-group (Brewer,
1993a). If a woman wants to see males and females as very distinct from each
other, she may simply come to believe that, as a group, women are very
similar to each other and men are very similar to each other. The woman
may also call on the stereotypes that exist of men and women and perceive
members of each of the groups as conforming more closely to their respec-
tive group stereotypes. In so doing, the woman would perceptually increase
group distinctiveness (thereby satisfying the need for distinctiveness) and
enhance in-group cohesion (thereby satisfying the need for inclusion).
These ideas were tested in a study by Pickett and Brewer (2001). Study
participants (Arts and Humanities students) were provided with feedback
that indicated that they were very different from other in-group members
(need for inclusion condition); that they were very similar to other in-group
members, but that the in-group was highly similar to an out-group (need for
differentiation condition); or that they were very similar to other in-group
members and the in-group was different from the out-group (control con-
dition). Participants were then asked to rate how homogenous they per-
ceived members of the in-group and out-group (Natural Science majors) to
be. To measure perceived in-group and out-group homogeneity, Pickett
and Brewer (2001) used a similarity task (Park & Judd, 1990) and a measure
of group stereotypicality. In the similarity task, participants were asked to rate
how similar they believed Arts and Humanities students to be along four
different dimensions—personality, academic ability, social life, and in gen-
eral. Participants repeated the similarity task a second time for Natural
Sciences students, rating how similar they believed Natural Sciences students
to be along the same four dimensions. Averaging across the four dimensions,
a clear effect of need arousal emerged (see Table 2.1). Participants in the need
for inclusion and differentiation conditions perceived the in-group and out-
group to possess greater intragroup similarity than did control participants.
The perceived stereotypicality of the in-group and out-group was
assessed using a percentage estimates task (Park & Judd, 1990). In this task,
participants received a list of stereotypic traits of Arts and Humanities
students followed by a list of stereotypic traits of Natural Sciences students
and were asked to estimate the percentage (from 0% to 100%) of students
82 Geoffrey J. Leonardelli et al.
within each of these groups that they believe possess each trait. Higher
estimates of the percentage of group members that share these traits are
indicative of a more stereotypical perception of the groups. As was the case
with the similarity measures, participants in the need for inclusion and the
need for differentiation conditions perceived the in-group and out-group
more stereotypically than did participants in the control condition. These
results suggest that threats to in-group inclusion and intergroup distinc-
tiveness may motivate individuals to establish clearer intergroup boundaries
through mechanisms such as enhanced intragroup similarity and
stereotypicality.
As described in previous sections, the needs for inclusion and differenti-
ation have been shown to be associated with a preference for groups that can
best meet those needs (e.g., Abrams, 2009; Andrijiw & Hyatt, 2009;
Dimmock, 2009; Hornsey & Hogg, 1999). When individuals have a desire
for greater in-group inclusion, they can selectively activate and identify with
groups that are more inclusive (e.g., categorizing the self as a psychologist
instead of a social psychologist). By the same token, when individuals desire
greater differentiation, they can categorize the self in terms of more exclusive
identities. However, this is only one potential means of satisfying the needs
for inclusion and differentiation. Individuals can also alter their perception
of or definition of a given in-group, with which they are already identified,
to make it fit existing need levels. Rather than look for new groups to meet
current need states, individuals can adapt or modify their cognitive repre-
sentation of existing in-groups to meet changes in needs for greater inclu-
siveness or distinctiveness. The more an individual is identified with a
particular in-group, the more likely they would be to adapt that in-group
to meet their needs rather than switch to alternative group identities.
Based on this theorizing, Pickett et al. (2002a,b) hypothesized that need
arousal could lead individuals to overestimate or underestimate the size of an
Table 2.1 Perceived in-group homogeneity by need state and similarity dimension
Need state
Similarity dimension
Personality
Social
life Academics
In
general
Assimilation motive 5.34 a 4.33 ab 5.10 a 5.21 a
Control 3.92 b 4.01 b 4.20 a 4.21 b
Differentiation
motive
5.33 a 5.04 a 5.12 a 5.18 a
From Pickett and Brewer (2001). Copyright Elsevier.
Note. Higher numbers reflect greater perceived in-group homogeneity. Cell means within the same
column that do not share a common letter differ significantly from each other at the p<0.05 level.
Optimal Distinctiveness Theory 83
existing important social identity group. In their study, Pickett et al. (2002a,b,
Study 2) gave highly identified Ohio State undergraduates feedback designed
to arouse either the need for inclusion, the need for differentiation, or neither
need (control) in relation to participants’ Ohio State identity. Participants
were then asked to estimate the size of the in-group (Ohio State under-
graduates) and also indicate their satisfaction with the size of the group (i.e.,
whether the group had too many or too few members).
Results of this study revealed a clear pattern of effects. Participants in the
need for inclusion condition significantly overestimated the size of the
group, whereas participants in the need for differentiation condition tended
to underestimate the size of the group. Control participants’ estimates were
quite accurate and did not significantly differ from the true size of the group
(see Fig. 2.3). In addition, participants in the need for inclusion and need for
differentiation conditions significantly differed in terms of their satisfaction
with the size of the group. Need for differentiation participants tended to
feel that the group had too many group members compared to need for
inclusion participants. Subsequent correlational analyses supported the con-
clusion that participants’ satisfaction with the size of the in-group predicted
their desire to restrict (or expand) group membership.
Taken together, the results of this study indicate that the needs for
inclusion and differentiation can have significant effects on group percep-
tion, such that features of the group that may seem to be fairly objective (e.g.,
group size) are subject to reinterpretation in ways that can help achieve need
satisfaction.
55,000
50,000
45,000
40,000
35,000
30,000
Estimated number of in-group members
25,000
20,000
15,000
10,000
Need for
assimilation
No need
arousal
Need for
differentiation
Figure 2.3 Need state on perceived in-group size (Study 2). Taken from Pickett et al.
(2002b). Copyright Sage/Society for Personality and Social Psychology.
84 Geoffrey J. Leonardelli et al.
4.3. Social judgments
Although the desire for optimal distinctiveness is most likely to affect how
individuals perceive the self and their in-groups, other types of judgments
might also be implicated in the process of need satisfaction. The needs for
inclusion and differentiation can affect social judgments in a variety of ways.
First, similar to how other goals and motivations operate, it is expected that
individuals should come to evaluate more positively objects, behaviors,
people, etc. that are viewed as helping them meet their goals. For example,
individuals who have a high need for inclusion should be more attracted to
group objects and symbols that convey in-group inclusion (e.g., a team
sweatshirt). Conversely, the need for differentiation should lead to greater
valuation of those objects and attributes that provide a basis for distinguish-
ing the in-group from other groups. Second, heightened needs for inclusion
and differentiations can change group members’ cognitive frame of refer-
ence. The desire for greater group distinctiveness may direct attention
inward such that subgroup differentiation can occur (in the case of large,
majority groups) or it may direct attention outward toward those features
that distinguish the in-group from the out-group. Under conditions of
heightened need for inclusion, group members are expected to be focused
on shared features of the in-group in contrast to the out-group. These
frame-of-reference changes may then have other judgmental effects, such
as directing with whom group members compare the self (Brewer &
Weber, 1994). Finally, the desire for optimal distinctiveness may act more
generally as a directional motivation that biases cognitive processing
directly—for example, affecting consensus estimates (Simon et al., 1997).
In this section, we consider the existing research evidence on the effects of
optimal distinctiveness needs on social judgment.
A common finding in the social psychological literature is that people
evaluate means to a currently activated goal positively. For example, if a
new Ph.D. recipient possesses the goal of being seen as a core member of his
or her academic field, then objects and symbols that convey membership
(both to the self and to others)—for example, a mug with the name of an
important society membership emblazoned on it—should become highly
valued, and there should be a greater desire to own the object. When the
needs for inclusion or differentiation have been aroused, the desired end-
state is either greater in-group inclusiveness or greater distinctiveness. In
one study, Timor and Katz-Navon (2008) examined the adoption of new
consumer products and found that the probability of adopting a new
product by consumers varied predictably as a function of participants’
reported levels of inclusion and differentiation needs and as a function of
how many other people participants believed already owned the product.
For example, participants who had a high need for differentiation and a low
need for inclusion were less likely to adopt products that they perceived as
Optimal Distinctiveness Theory 85
being owned by a large number of other people. The opposite pattern
emerged for participants who had a high need for inclusion and a low need
for differentiation. These participants were more likely to own products that
many other people also owned. These results suggest that arousal of the
needs for inclusion and differentiation can bias people’s judgments of goal-
relevant objects.
In a study of intergroup comparisons, Brewer and Weber (1994) tested
the prediction that optimal group distinctiveness would shape social com-
parison processes. These researchers manipulated in-group size and exam-
ined its effect on participants’ reactions to in-group and out-group
comparison targets. Based on the predictions of optimal distinctiveness
theory, Brewer and Weber (1994) hypothesized that being a member of a
large majority group would arouse participants’ need to differentiate the self
from other in-group members, thereby making the relevant target of
comparison other members of the in-group. However, membership in a
relatively small minority group would enhance in-group assimilation and
intergroup comparison. The experiment consisted of a 2 (majority or
minority in-group size) 2 (upward or downward comparison) 2-
(in-group or out-group target) between-subjects factorial design. Partici-
pants were categorized into majority or minority groups based on a bogus
perceptual test and were then presented with a videotaped interview of
either an in-group or out-group member who was portrayed as being either
highly competent (an upward comparison target) or incompetent and
unsuccessful (a downward comparison target).
These researchers found that majority group members exhibited inter-
personal (i.e., within group) comparison effects: exposure to an in-group
upward comparison target resulted in lower self-ratings, whereas an out-
group upward comparison target had no effect on participants’ self-evalua-
tions. By contrast, subjects in the minority in-group showed the opposite
pattern: exposure to an in-group comparison target resulted in assimilation,
such that participants’ self-ratings were higher after exposure to the in-
group upward comparison target than after exposure to an in-group down-
ward comparison. Furthermore, minority group members showed contrast
effects in response to out-group members: participants’ self-ratings were
lower after exposure to an out-group upward comparison target than they
were after exposure to an out-group downward comparison target. Brewer
and Weber (1994) concluded from these findings that individuals’ responses
to social comparison targets vary as a function of the distinctiveness of the
in-group.
One type of judgment that individuals make fairly regularly is assessing
how widely shared their beliefs, attitudes, and preferences are. Social psy-
chological research has demonstrated that these judgments are often shaped
by motivations such as social desirability (e.g., Krueger & Clement, 1994;
Suls et al., 1988) and are also affected by threats to the self (e.g., Sherman
86 Geoffrey J. Leonardelli et al.
et al., 1984). Simon et al. (1997) hypothesized that one way of coping with
threats to inclusion and differentiation is by altering one’s perception of how
many other people share one’s views. Simon et al. (1997) argued that people
can feel included in social categories by perceiving themselves as sharing
attributes with other group members. Conversely, the desire for (personal)
differentiation can be satisfied by underestimating consensus for one’s views
(e.g., Campbell, 1986). In addition, these researchers predicted that threats
to inclusion and differentiation would have greater impact under conditions
of mortality salience because, according to their theory, the needs for
inclusion and differentiation serve a higher-order terror management func-
tion. Achieving optimal distinctiveness (simultaneously fitting in and stand-
ing out) can help to affirm one’s worldview and enhance self-esteem, which
can then buffer the self from anxiety regarding death and mortality.
To test their hypotheses, Simon et al. (1997) gave participants person-
ality feedback that described participants as either being socially deviant
(need for inclusion condition), conformist (need for differentiation condi-
tion), or neutral (control condition). Participants were also randomly
assigned to write about either their own mortality or another aversive
experience (an upcoming exam). Participants then completed a social
projection measure. Using materials adapted from Krueger and Clement
(1994), these researchers had participants indicate their degree of endorse-
ment of a series of statements (e.g., ‘‘I like poetry’’) and also indicate what
percentage of the population they thought would endorse each of the
statements. As predicted, under conditions of mortality salience, partici-
pants who received feedback indicating that they were socially deviant
estimated higher consensus for their beliefs than control participants. By
contrast, participants who were told that they were conformist reported
significantly lower levels of consensus for their beliefs than control parti-
cipants. These results suggested that individuals may strategically alter their
judgments of consensus in a way that meets currently activated needs for
inclusion or differentiation.
4.4. Summary of social cognition
In sum, a growing body of research demonstrates that the needs for inclu-
sion and differentiation can alter perceptions of the self, perceptions of the
group, and social judgments in ways that allow individuals to achieve a sense
of optimal distinctiveness. In response to a heightened need for inclusion or
differentiation, individuals have been shown to engage processes such as
emotional and trait self-stereotyping, altering judgments of group member-
ships through perceptions of relative size or enhanced perceptions of both
in-group and out-group homogeneity, perceptions of consensus, and social
comparison. Thus, studies employing different methods for arousing or
activating the needs for inclusion or differentiation provide convergent
Optimal Distinctiveness Theory 87
evidence that individuals respond to deprivation of these identity needs by
altering their cognitive representations of the self, the in-group, or the social
context in ways that increase need satisfaction and restore optimal identity.
5. Implications for Intergroup Relations
With respect to intergroup behavior, social identity theory (Tajfel &
Turner, 1979) has focused on the phenomenon of in-group favoritism, the
pervasive tendency for group members to exhibit preferential treatment of
members of their own in-group over members of out-groups (Brewer,
1999; Tajfel et al., 1971). Optimal distinctiveness theory provides another
perspective on the motivations underlying in-group bias and favoritism,
proposing that members of groups at different levels of inclusiveness exhibit
such intergroup discrimination, but do so for different reasons (Pickett &
Leonardelli, 2006). On the one hand, individuals may turn to in-group
favoritism to achieve or restore in-group optimality, whether to enhance
their sense of inclusion or imbue their group (and themselves by extension)
with a sense of distinctiveness. On the other hand, individuals who are
already members of optimally distinct groups may exhibit in-group favorit-
ism to maintain membership in an optimally distinct group.
The following sections summarize research that we and others have
conducted investigating the connection between optimal distinctiveness
and intergroup behavior. The first section reviews evidence documenting
how membership in optimally distinctive and nondistinctive group mem-
berships (minority and majority groups, respectively) can both lead to in-
group favoritism, but that this favoritism originates from different motiva-
tional bases. The second and third sections document how arousal of the
needs for inclusion and differentiation can manifest as intergroup behavior,
and the fourth section discusses the strength of optimal distinctiveness
motives relative to other motives (i.e., intergroup status) as engines for
intergroup behavior.
5.1. Intergroup behavior in minority–majority relations
The goal of our first research study (Leonardelli & Brewer, 2001) was to test
whether minority and majority group members both exhibit in-group
favoritism, and whether they do so for different reasons. Evidence had
already documented that members of numerical minorities spontaneously
exhibit greater in-group favoritism than majority group members (e.g.,
Gerard & Hoyt, 1974; for a meta-analysis, see Mullen et al., 1992). The
typical explanation for the effect had been that in-group favoritism reflects a
desire to compensate for a group membership perceived to be less powerful,
88 Geoffrey J. Leonardelli et al.
less secure, or of lower status than numerical majorities (e.g., Bettencourt
et al., 1999; Ellemers et al., 1992; Ferguson et al., 1990; Jost & Banaji, 1994;
Levine & Moreland, 1998; Sachdev & Bourhis, 1984, 1991; Simon et al.,
2001). By contrast, optimal distinctiveness theory (Brewer, 1991;
Leonardelli & Brewer, 2001) argues that in-group favoritism by minority
group members is an expression of membership preference and support, and
the lower in-group favoritism exhibited by majority group members reflects
disengagement from a nondistinctive (and nonpreferred) group member-
ship (for consistent theoretical support, see also Imhoff & Erb, 2009).
However, to the extent that majority group members are induced to
identify with the majority group, so that disengagement is no longer an
option, they would be motivated to find other means to achieving distinc-
tiveness, including exhibiting in-group favoritism.
Three experiments tested these predictions. The first examined whether
minority and majority group members would both exhibit in-group favor-
itism when they were induced to identify with their group. According to
optimal distinctiveness theory, members of numerical minorities should
already be engaged in and satisfied with their group identity, and thus,
inducing collective identification will not affect their level of in-group
favoritism. By contrast, majority group members should be dissatisfied
with and thus disengaged from their nondistinctive group membership,
but if collective identification were experimentally induced, majority
group members will turn to other ways of responding to nondistinctiveness,
such as through in-group favoritism. Thus we predicted an interaction
between relative in-group size and social identity induction, where in-
group favoritism will be high for minority group members regardless of
the identity induction, but that majority group members will exhibit greater
in-group favoritism under high rather than low identity induction.
To test this predicted interaction, undergraduate participants were first
randomly assigned to minority or majority group membership using the
minimal group paradigm (Tajfel et al., 1971), with groups formed from a
dot estimation task that ostensibly represented 20–25% or 75–80% of the
population, respectively. We created a collective identification induction by
employing a biased questionnaire manipulation (Salancik, 1974), where
group members induced to identify with their group were led to believe
that behaviors descriptive of the in-group were also descriptive of
themselves.
Participants then completed a four-item measure of in-group favoritism,
where for each item they selected which hypothetical payoff from a series of
payoffs they would give to a member of their group (other than themselves)
and a member of the out-group (e.g., see Fig. 2.4). For this measure (adapted
from Tajfel et al., 1971, Matrix Type B in Study 1), payoffs were interdepen-
dent such that higher payoffs to the in-group member meant lower payoffs to
the out-group member. Choices could range from favoring the out-group, to
Optimal Distinctiveness Theory 89
minimizing differences, to favoring the in-group, and were scored such that
positive numbers indicated greater in-group favoritism.
Analysis of the payoff choices yielded a significant interaction effect.
Under low induction, consistent with past research (e.g., Gerard & Hoyt,
1974), minority group members spontaneously exhibited greater in-group
favoritism than majority group members. However, under high induction,
minority and majority group members exhibited in-group favoritism to the
same degree. Additional analyses revealed that high relative to low identity
induction yielded greater in-group favoritism for majority group members,
but that minority in-group favoritism remained high regardless of induction.
This study confirmed that with sufficient identification, minority and major-
ity group members exhibit in-group favoritism. However, we expected the
motivational basis to be different for minority and majority group members,
and the subsequent two studies investigated how that might be so.
According to optimal distinctiveness theory, in-group favoritism is an
expression of membership preference and group support for minorities, but
for majorities, it is expected to reflect an effort to make their nondistinctive
(and thus, dissatisfying) group more distinctive. Such different motivational
explanations should be manifest in different associations between the group
members’ satisfaction with their group and their level of in-group favorit-
ism. Degree of in-group favoritism by minority group members was
hypothesized to be an expression of group satisfaction and support, and
thus, it was expected that in-group satisfaction would positively predict
minority in-group favoritism: as in-group satisfaction increases, minority
in-group favoritism increases. On the other hand, in-group favoritism by
majority group members was hypothesized to be an attempt to make the
nondistinctive (and thus, dissatisfying) majority group more distinctive; as a
result, it was expected that in-group satisfaction would be negatively related
to majority in-group favoritism such that the more dissatisfied group mem-
bers were with their group, the more they would exhibit in-group
favoritism.
These are the potential rewards for:
In-group
member
Out-group
member
123 456789 10 11 13 14
14 13 12 11 10 9 8 7654
12
321
Figure 2.4 This example represents a standard measure of in-group favoritism (taken
from Tajfel et al., 1971, Matrix Type B, Experiment 1), a zero-sum matrix, where
individuals decide on whether to exhibit in-group favoritism, out-group favoritism, or
minimize differences. The oval illustrates how individuals respond to these matrices (by
circling one column of numbers).
90 Geoffrey J. Leonardelli et al.
Our second experiment tested this predicted interaction between rela-
tive size and in-group satisfaction. Research participants were randomly
assigned to membership in a minimal minority or majority group using the
procedure from the first study, and all group members were induced to
identify with their group using the high induction procedure from Study 1
so that majority group members would also exhibit in-group favoritism to
the same extent as minority group members. Participants then completed a
four-item measure of in-group satisfaction designed for this study (e.g.,
‘‘I am satisfied with this group’’). Finally, participants completed the mea-
sure of in-group favoritism from the first study. Submitting in-group
favoritism scores to a regression analysis revealed a significant interaction
between relative in-group size and in-group satisfaction (Fig. 2.5). For
minority group members, in-group favoritism increased as in-group satis-
faction increased, but for majority group members, in-group favoritism
increased as in-group satisfaction decreased. This interaction is consistent
with the notion that minority in-group favoritism is an expression of
membership preference, whereas majority in-group favoritism is a compen-
satory response to their group’s lack of distinctiveness.
The data from Study 2 supported the notion that in-group favoritism by
minority and majority group members would manifest as an expression of
membership preference or to gain group distinctiveness, respectively. Study
3 sought to gain additional support by testing whether minority and major-
ity in-group favoritism reflect different underlying social orientations
(Messick & McClintock, 1968; Tajfel et al., 1971). Social orientations are
individuals’ preferences in interdependent contexts often reflecting whether
Low
30
25
20
15
10
Difference score
5
0
High
In-group satisfaction
Minority members
Majority members
Figure 2.5 Relative in-group size (minority, majority) in-group satisfaction (con-
tinuous) on zero-sum in-group favoritism scores (Study 2). Taken from Leonardelli and
Brewer (2001). Copyright Elsevier.
Optimal Distinctiveness Theory 91
individuals are motivated to be prosocial (other-oriented) or proself in their
distributions of resources. Of particular interest to our predictions is the
distinction between two social orientations for in-group favoritism—abso-
lute and relative in-group favoritism (also referred to as ‘‘maximum in-
group profit’’ and ‘‘maximum differentiation,’’ respectively). These two
social motives differ in an important way: With absolute in-group favorit-
ism, group members are motivated to maximize the absolute value of the in-
group’s outcome (regardless of the outcome to the other group), whereas
with relative in-group favoritism, group members are more concerned with
maximizing the favorable difference between their own group’s outcome
and the other group’s outcome.
In-group favoritism on measures such as those used in Studies 1 and 2 do
not differentiate between these orientations and could reflect either. To
identify which orientation individuals exhibit, researchers require measures
that distinguish between these social orientations, such as by using the Tajfel
pull score matrices (Billig & Tajfel, 1973; Tajfel et al., 1971, Experiment 2)
or other distribution choice measures (e.g., Bornstein et al., 1983a,b;
Griesinger & Livingston, 1973; Liebrand, 1984). Figure 2.6 contains a
sample matrix from the Tajfel matrices (which is what we used in the
following study) with payoffs that distinguish between absolute and relative
in-group favoritism; in the extreme, those who prefer relative in-group
favoritism would prefer outcomes on the left (sacrificing absolute benefit to
the in-group for gain relative to the out-group), whereas those who prefer
absolute in-group favoritism would move to the right.
2
These are the potential rewards for:
In-group
member
Out-group
member
7 8 910111213141516171819
1 3 5 7 9 1113151719 21 23 25
Figure 2.6 This example of a Tajfel allocation matrix (taken from Tajfel et al., 1971,
Matrix Type B, Experiment 2) assesses different orientations (‘‘pulls’’) group members
have to exhibiting in-group favoritism. This particular matrix contains payoffs that
emphasize the different orientations for absolute and relative in-group favoritism; in the
extreme, those who prefer relative in-group favoritism would prefer outcomes on the
left, whereas those who prefer absolute in-group favoritism would prefer outcomes on
the right.
2
The matrix in Fig. 2.6 illustrates the Tajfel pull score matrices and how they are arranged to create competing
pulls between one type of social orientation and another (in the example matrix, the competition occurs
between absolute and relative favoritism). However, the calculation of pull scores is more complex, requiring
participants’ responses on another matrix where the orientations are not in competition. It is highly
recommended that readers interested in using the Tajfel pull score matrices read one of the available
discussions on calculating pull scores before using these matrices (e.g., Bourhis et al., 1994).
92 Geoffrey J. Leonardelli et al.
According to optimal distinctiveness theory, in-group favoritism by
minorities and majorities is an expression of membership preference or an
attempt to make their nondistinctive group more distinctive, respectively.
We expected that minority group members would be more likely to exhibit
absolute in-group favoritism because it represents the strongest signal of
group support, but that majority group members would be more likely to
exhibit relative in-group favoritism because it could be used to differentiate
the in-group from the out-group.
Study 3 tested these predictions. Participants were randomly assigned to
a minority or majority category, induced to identify with their group, and
completed the Tajfel pull score matrices. Analysis revealed that minority
group members were more likely to exhibit absolute in-group favoritism
than majority group members. By contrast, majority group members only
exhibited relative in-group favoritism.
The evidence collected by Leonardelli and Brewer (2001) supports the
predictions from optimal distinctiveness theory. They found that, with
sufficient group identification, minority and majority group members
exhibit in-group favoritism to similar degrees, but do so in different ways.
Minority group members exhibited greater in-group favoritism with greater
group satisfaction, and exhibited greater absolute in-group favoritism than
majority group members, evidence consistent with the notion that minority
in-group favoritism is an expression of membership preference and support.
By contrast, majority group members exhibited greater in-group favoritism
with greater in-group dissatisfaction and exhibited relative in-group favorit-
ism, consistent with the notion that majority in-group favoritism is moti-
vated to achieve group distinctiveness. The above evidence goes far to
support the notion that minority and majority in-group favoritism serve
different functions, and since then, research has sought to more specifically
identify the regulatory functions that govern minority in-group favoritism.
Based on their evidence, Leonardelli and Brewer (2001) concluded that
in-group favoritism by minority group members was an affirmation of the
in-group identity, that is, an expression of membership preference and in-
group support. Elaborating on this motivational premise, Leonardelli (2010)
argued that in-group favoritism for optimally distinct in-groups serves a
membership maintenance function. This membership maintenance motive
is rooted in the psychological experience of ‘‘member self-integrity,’’ where
group members evaluate whether they are currently good group members
and use this psychological experience to regulate whether they exhibit
expressions of group support. More specifically, member self-integrity is
expected to regulate and maintain group membership by operating as a
negative feedback loop (Abrams, 1994b; Carver & Scheier, 1982; Miller
et al., 1960), which yields three predictions. First, as member self-integrity
decreases, group members should be more likely to subsequently
exhibit group-serving behaviors (such as in-group favoritism). Second, to
Optimal Distinctiveness Theory 93
the extent that group members are successful in exhibiting these group-
serving behaviors, group members’ sense of member self-integrity should
subsequently increase (i.e., they should feel like they have successfully
maintained their membership). Third, after recently exhibiting an expres-
sion of group support, group members should be less likely to exhibit
group-serving behaviors again in the near future.
Leonardelli and Galinsky (2010) tested whether this model of member-
ship maintenance could explain in-group favoritism by minority group
members. They devised a measure of member self-integrity where group
members rate to what degree they feel they are meeting the standards of
good group membership. This measure was then used to test the three
predictions derived from the negative feedback loop model. Specifically, for
minority group members only, it was proposed that (1) as member self-
integrity decreases, in-group favoritism should subsequently increase, (2) as
in-group favoritism increases, member self-integrity should subsequently
increase, and (3) prior expressions of group support should lead to less
subsequent in-group favoritism. Finding support for all three predictions
would be consistent with the notion that in-group favoritism by minority
group members reflects their motivation to maintain membership in the
numerical minority. By contrast, members of numerical majorities are
expected to be dissatisfied with their group’s lack of distinctiveness, and
in-group favoritism by them should be more likely to reflect the motivation
to achieve distinctiveness rather than to maintain membership.
Thus, these predictions were expected to apply only for members of the
numerical minority.
Three studies tested each of these predictions in turn. In one study, we
tested whether lower member self-integrity is associated with subsequently
greater in-group favoritism by minority but not majority group members.
In this study, participants were asked to first self-select one of their existing
social category memberships and rate the degree to which they perceived
their social category to be smaller or larger than a comparison group. After
doing so, they then rated their degree of member self-integrity, and then
completed the Tajfel pull matrices (Tajfel et al., 1971). As noted by
Leonardelli and Brewer (2001), in-group favoritism by minority group
members is expected to manifest as absolute in-group favoritism (as this is
the strongest expression of group support). As a result, we expected that
lower member self-integrity should be associated with higher absolute
in-group favoritism for minority but not majority group members, whereas
we did not expect this interaction to occur on relative in-group favoritism.
A hierarchical regression analysis revealed a significant interaction on
absolute in-group favoritism (Fig. 2.7). Consistent with predictions, minority
group members who reported relatively low member self-integrity exhibited
the highest level of absolute in-group favoritism. However, analysis of relative
in-group favoritism did not yield this interaction. This study thus supported
94 Geoffrey J. Leonardelli et al.
the first prediction of the membership maintenance model, namely that lower
member self-integrity yielded greater in-group favoritism. Furthermore, that
this effect was limited to minority, but not majority, group members support
the notion that minority group members are more likely than majority group
members to be motivated to maintain group membership.
In another study, we tested the second half of the negative feedback
loop, namely that greater in-group favoritism should yield greater
subsequent feelings of member self-integrity. Furthermore, if membership
maintenance was primarily the motive to describe minority rather than
majority in-group favoritism, then this effect should be limited to minority
rather than majority group members. To test this interaction, participants
recruited from an online research pool were randomly assigned into mini-
mal groups using a categorization task created for this study, where partici-
pants reported which of the two images in a series of optical illusions came
to mind first. Ostensibly based on their responses, participants were classi-
fied as members of the ‘‘spatial’’ group and were randomly assigned to learn
that their social category was in the minority or majority relative to the
other ‘‘temporal’’ group. Because the study investigated the consequences
of exhibiting in-group favoritism, it was important that majority group
members also exhibit in-group favoritism; thus, all participants were then
induced to identify with their group (Leonardelli & Brewer, 2001).
12
10
8
6
4
2
Absolute in-group favoritism pull score
0
Majorities (–1SD)
Low (–1SD) High (+1SD)
Minorities (+1SD)
Relative in-group size
Member self integrity
Figure 2.7 Relative in-group size (continuous) member self-integrity (continuous)
on absolute in-group favoritism scores (Study 2). Taken from Leonardelli and
Galinsky (2010).
Optimal Distinctiveness Theory 95
Participants were then randomly assigned to one of three conditions,
whether to complete a measure of in-group favoritism, to complete a
control measure where participants allocated hypothetical payoffs to two
randomly selected individuals, or to receive no measure at all. Finally,
participants completed the measure of member self-integrity. If in-group
favoritism was intended to maintain group membership, then it was
expected that minority group members who could exhibit in-group favor-
itism would report higher levels of member self-integrity than those from
the control or no measure conditions. However, because majorities were
not expected to be motivated by membership maintenance, their member
self-integrity scores were not predicted to differ across the different mea-
surement conditions.
Analyses revealed the predicted interaction: minority group members
who had the opportunity to exhibit in-group favoritism reported greater
member self-integrity than minority group members who did not, and
more than majority group members who did. Internal analyses conducted
with participants who had the opportunity to exhibit in-group favoritism
also revealed that member self-integrity increased as the level of in-group
favoritism increased, and this correlation was significant for minority, but
not majority, group members. In-group favoritism by minority, but not
majority, group members led to feelings of member self-integrity.
These two studies supported the notion that, for minority group mem-
bers only, lower member self-integrity leads to higher subsequent in-group
favoritism, and that higher in-group favoritism yields greater member self-
integrity, consistent with a membership maintenance explanation. A third
prediction was tested in Study 3, namely that, were minority group mem-
bers given an alternative means of exhibiting group support, then they
should exhibit less in-group favoritism. Such evidence would support the
notion that membership maintenance not only explains why in-group
favoritism is exhibited by minority group members, it also helps to explain
when they will do so: when they have not already maintained group
membership through alternative means of group support. As before, given
that in-group favoritism by majority group members is not expected to be
regulated by a membership maintenance motive, these effects should occur
for minority but not majority group members.
To conduct this test, participants were first classified into minimal groups
using a painting preference task, and were told that they belonged to a
numerical minority or majority relative to another painting preference
group. All participants were induced to identify with their group so that
the study could investigate whether alternative expressions of group support
would reduce the in-group favoritism of minority or majority group mem-
bers. Finally, prior to completing measures of in-group favoritism, partici-
pants were randomly assigned to engage in or not engage in an alternative
expression of group support. This manipulation was modeled on one pulled
96 Geoffrey J. Leonardelli et al.
from the self and identity literature (e.g., McQueen & Klein, 2006), where
individuals express how important particular values are to them personally.
Previous research assumes that such personal ‘‘self-affirmations’’ strengthen
individuals’ sense of global self-integrity, where they feel good, moral, and
competent (Steele, 1988; see also Sherman & Cohen, 2006). To create a
strong expression of group support, we adapted this manipulation so that
some participants conducted a ‘‘collective self-affirmation,’’ and wrote
about the relevance of important values to making a contribution to
their group. Other participants were assigned to conduct a personal self-
affirmation, where they wrote about the relevance of important values to
themselves personally, or to a control condition, where they did not write
about anything.
We predicted that minority group members in the collective self-affir-
mation condition would report lower in-group favoritism than those in the
personal self-affirmation and control conditions, because we expected that
membership maintenance is regulated primarily by expressions of group
support rather than any form of (personal) support. Furthermore, we
expected that these effects would be limited to minority rather than major-
ity group members. The self-affirmation manipulation, which targets dif-
ferent types of personal or group expressions of support, has no direct
consequence for achieving group distinctiveness, the motive we expect to
explain majority in-group favoritism. As such, we expected the manipula-
tion to have no effect on majority group members’ in-group favoritism.
Analysis of in-group favoritism revealed a significant interaction as
predicted. Whereas majority in-group favoritism did not differ across con-
ditions of the self-affirmation manipulation, minority in-group favoritism
was lower in the collective self-affirmation than in the other two conditions.
Overall, the research in this domain established a number of conclusions.
First, it demonstrated that, with sufficient identification, minority and
majority group members can exhibit in-group favoritism to similar degrees,
but that this favoritism serves fundamentally different functions. Second, in-
group favoritism by majority group members appears to be motivated to
achieve group distinctiveness. Third, in-group favoritism by minority
group members appears to be motivated by a membership maintenance
motive rather than as a means to compensate for membership in an
insecure group.
5.2. Achieving inclusion through intergroup behavior
The research findings discussed thus far provide insight into the nature of
in-group favoritism exhibited by moderately inclusive (minority) and
highly inclusive (majority) groups. But as noted earlier, there is reason to
believe individuals may also exhibit in-group favoritism to meet their need
for inclusion in an effort to gain acceptance or inclusion. Empirical support
Optimal Distinctiveness Theory 97
(albeit indirect) exists for this prediction. Research investigating peripheral
membership in groups (e.g., Jetten et al., 2002; Noel et al., 1995) reveals
that peripheral in-group status (current or anticipated) can influence levels
of in-group bias. For example, Noel et al. found that fraternity and sorority
pledges, individuals who see themselves as peripheral members of their
pledged fraternity or sorority, were more likely to exhibit out-group dero-
gation than were active (i.e., core) fraternity and sorority members. Impor-
tantly, this effect was only observed in the public condition, where
participants’ out-group derogating responses were known to other group
members. This suggests, then, that when the need for inclusion has been
activated (e.g., through manipulations of peripheral status), in-group bias
may be more likely to occur when it can be used as a means of signifying to
other group members that one is loyal to the group and thus deserves to be
included within it.
In addition, work by Jetten et al. (2002) suggests that for peripheral in-
group status to produce in-group favoritism, individuals must believe that
their atypical status will change. Jetten et al. reported that peripheral group
members who believed their peripheral status would improve over time
were more likely than peripheral members who did not think their status
would improve to exhibit in-group favoritism. Although these studies did
not specifically measure inclusion need arousal, the work does point to a
link between conditions where the need for inclusion is likely to be unmet
(e.g., being a marginal group member) and increased levels of in-group bias.
Further research is needed, however, to obtain clear empirical support for
the relation between heightened inclusion need arousal and levels of
in-group bias and to elucidate the moderators of this relation.
More recently, Zhong et al. (2008) explored the connection between
inclusion needs and group identification in a particularly novel way, by
investigating the effects of negational categorization on intergroup behav-
ior. To date, most research on social categorization processes has investi-
gated what could be called affirmational categorization, where groups of
people are defined by what they represent (we are social psychologists,
Catholics, Liberals, Americans). However, groups of people can also be
defined by what they are not (we are not economists, racists, elitists,
European). In a series of studies, we revealed that first, when the need for
differentiation is activated, individuals generated more negational categories
than when their need for inclusion was activated and relative to a control
condition, supporting the notion that negational categories primarily
contribute a sense of group distinctiveness. Second, three studies demon-
strated that, using minimal group procedures, members of negational
relative to those in affirmational categories were more likely to exhibit
out-group derogation.
We argued that the out-group derogation effect was due to negational
group members’ perpetuation of an existing contrast between self and
98 Geoffrey J. Leonardelli et al.
out-group that negational categorization naturally manifests, which might
have a motivational element as well. Given the absence of in-group inclu-
siveness in negational categories, it is possible that members of negational
categories more than those in affirmational ones would feel that out-group
derogation was one way to maintain what little shared sense of categoriza-
tion there is. Exhibiting out-group derogation is a way of maintaining the
meta-contrast ratio, that is, of keeping intergroup difference greater than
intragroup difference. For these reasons, we argued that creating a sense of
in-group inclusiveness would help to reduce out-group derogation, as it
would focus group members on in-group similarities rather than out-group
differences. In two studies, creating a sense of inclusiveness through a
‘‘we’’ prime (Study 3) or through depersonalization (Study 4) reduced the
degree of out-group derogation that members of negational categories
exhibited.
5.3. Achieving distinctiveness through intergroup behavior
Support also exists for the claim that a need for distinctiveness motivates in-
group favoritism, as indicated by the findings for majority groups summar-
ized previously. The role of distinctiveness motives in intergroup behavior is
also supported by research on intergroup similarity (e.g., Brown & Abrams,
1986; Diehl, 1988; Jetten et al., 1996, 2001, Study 2; Mummendey &
Schreiber, 1984; White & Langer, 1999). This research is based on the idea
that very high levels of similarity between groups can threaten group mem-
bers’ sense of their group’s distinctiveness and provoke in-group favoritism
in an effort to restore distinctiveness. Consistent with this idea, a meta-
analysis ( Jetten et al., 2004) found that high intergroup similarity was
associated with in-group favoritism on behavioral measures of discrimina-
tion (e.g., reward allocation) among those highly identified with the in-
group (although there was an opposite effect on judgmental measures).
Hornsey and Hogg (1999) also yielded evidence supporting this predic-
tion. These researchers were interested in investigating nested categoriza-
tion contexts, where individuals belong to subgroups nested within more
inclusive superordinate groups. According to optimal distinctiveness theory
(Brewer, 1993b), the more inclusive superordinate groups are perceived to
be, the more group members should be motivated to turn to the more
exclusive subgroups within the superordinate by exhibiting greater identifi-
cation with or favoritism for their subgroup. Hornsey and Hogg (1999)
tested this prediction with University of Queensland students, in either
math-science or humanities faculty areas, and were led to perceive their
university as the superordinate group and their faculty area as their subgroup
relative to other faculty areas. Hornsey and Hogg (1999) first measured
perceptions of superordinate inclusiveness, to determine whether group
members felt the superordinate category was too inclusive. In addition,
Optimal Distinctiveness Theory 99
the researchers experimentally manipulated category salience. Participants
first completed a ‘‘psychological perceptiveness task, ’’ where they inter-
preted what was happening in a picture. Participants in the superordinate
condition were then told that their responses would be compared to
responses of members in another social category, town planners. Partici-
pants in the simultaneous condition completed the same task, and were told
that their responses would be compared to those of town planners and that
responses by math-science students would be compared to those by huma-
nities students. It was expected that participants in the superordinate condi-
tion would feel part of a highly inclusive category and would thus be more
likely to engage in subgroup differentiation.
Participants then rated their subgroup identification and intergroup
behavior. Analysis revealed that greater perceptions of superordinate inclu-
siveness were associated with greater subgroup differentiation whereby
subgroup members expressed a preference for their subgroup over the
other subgroup. Interestingly, additional analyses revealed that this effect
appeared to be nonlinear; when the superordinate group was perceived to
be fairly distinctive (i.e., when analysis of superordinate inclusiveness was
conducted with scores from the bottom half of the scale) no relation
between superordinate inclusiveness and subgroup differentiation was
observed. Rather, the positive relation between superordinate inclusiveness
and subgroup differentiation was evident when the analysis was conducted
with superordinate scores from only the top half of the scale. Thus, only
when the superordinate category was perceived to be highly inclusive that
group members exhibited higher levels of subgroup favoritism. This evi-
dence is consistent with the notion that too much inclusiveness leads group
members to preserve and retain the distinctiveness of their subgroup.
5.4. Relative strength of different identity needs
The accumulated evidence indicates that, all things being equal, individuals
will prefer membership in more distinctive groups, particularly numerical
minorities. However, there are other bases for in-group identification and
intergroup behavior (Correll & Park, 2005). For example, social identity
theory (Tajfel & Turner, 1979) argues that a motivational basis governing
intergroup behavior is the need for positive distinctiveness and self-esteem;
when membership in a particular social category is incorporated in an
individual’s self-concept, self-esteem increases as the relative status of the
in-group increases in comparison to relevant out-groups. Thus, other things
being equal, individuals should prefer to identify with groups that are
positively valued or occupy high social status relative to other groups.
But other things are rarely equal. In many contexts, minority size is
confounded with disadvantages in status or power. Under these circum-
stances, the need for positive social identity and the need for distinctiveness
100 Geoffrey J. Leonardelli et al.
may come into conflict. Membership in a high-status majority group may
satisfy social esteem needs, but does not achieve optimal distinctiveness.
Conversely, categorization into a low-status minority group provides for
distinctive social identity but makes it more difficult to derive positive social
value from that group membership. Thus, the extent to which members of
majorities and minorities value and identify with their respective groups
should be moderated by the relative importance of the needs for distinc-
tiveness and the maintenance of positive self-esteem.
Brewer et al. (1993) sought to test this need strength hypothesis. In
particular, they examined whether minority and majority group members
would be particularly likely to exhibit favorability for their in-group
depending on their group’s status and whether their need for differentiation
had been aroused. A three-way interaction was predicted: under control
conditions, the combined presence of majority size and status should yield
greater in-group favoritism, but when the need for differentiation has been
aroused, minority group members should be more likely than majority
group members to exhibit in-group favoritism, regardless of level of
in-group status.
The need for differentiation was manipulated at the outset of the study.
Participants were randomly assigned to a control condition where they read
standard assurances about confidentiality and were allowed to generate
an ID number to be used during the course of the study. Those in
the ‘‘depersonalization’’ condition, however, received an instruction set
intended to increase the need for differentiation:
Since in this study we are not interested in you as an individual but as a
member of the college student population, we do not ask for any personal
information. However, for statistical purposes we need to match up differ-
ent questionnaires completed by the same person. In order to do this, we
have assigned you an arbitrary code number that is to be used throughout
this session. ...We are running this study in order to assess the attitudes and
perception of students in general. For the purposes of this study you
represent an example of the average student no matter what your major
is. We are only interested in the general category and not in individual
differences.
After completing the instruction set, participants were randomly
assigned to social categories using the minimal group paradigm, in particular
‘‘overestimator’’ or ‘‘underestimator’’ categories; at this time, participants
also were told that they belonged to a relatively large or small social
category. The majority category was counterbalanced with category label.
Participants then completed a test that was described either as a ‘‘Pattern
Preference’’ or ‘‘Perceptual Intelligence’’ test, where the test description
was intended to create status-neutral or status-value differences based
on group membership performance. Participants then received feedback,
Optimal Distinctiveness Theory 101
where overestimators consistently scored higher on the tests than under-
estimators. As a result, participants were thus assigned to either a status-
neutral condition (for those who completed the pattern preference test) or
membership in a high status or low status group (for those who completed
the perceptual intelligence test). Finally, participants completed trait evalua-
tions of their group and the other group, which represented the measure of
in-group favoritism.
Analysis revealed a three-way interaction between depersonalization,
relative in-group size, and relative in-group status on positive in-group
traits. Under control conditions, majority size and status both led to more
positive in-group trait ratings; however, under depersonalization, minority
size led to more positive trait ratings, and there was no main effect of group
status, nor did it interact with relative size. Under depersonalization,
minority size mattered more than in-group status.
5.5. Summary of intergroup relations
The literature reviewed here supports the claim that the needs for inclusion
and differentiation motivate in-group favoritism. First, evidence from stud-
ies on minority–majority relations is consistent with the notion that in-
group favoritism by minority and majority group members occurs out of a
desire to maintain or achieve optimal distinctiveness, respectively. Second,
evidence also directly supports the notion that arousal of the needs for
inclusion and differentiation will motivate in-group favoritism. Although
optimal identity needs are not postulated to be the only motives underlying
in-group favoritism, when these motives are strong, they may take prece-
dence over other social needs, such as status-seeking.
6. Recent Advances and Future Directions
6.1. Extending the optimal distinctiveness model
Optimal distinctiveness theory was originally intended to apply exclusively
to the collective social self. However, the basic underlying tension between
inclusion and differentiation most likely plays itself out in other aspects of
self-construal as well. Brewer and Gardner (1996) postulated that there are
three distinct levels of self-representation that constitute the ‘‘social self.’’ In
place of existing dichotomies that contrasted individual/independent versus
interpersonal/interdependent self-construals (Cross & Madson, 1997;
Markus & Kitayama, 1991) on the one hand, or personal versus social/
group identities (Hogg & Abrams, 1988; Turner et al., 1987) on the other,
they proposed a tripartite model, distinguishing among individual, relational,
and collective self-representations. Further, they suggested that these are not
102 Geoffrey J. Leonardelli et al.
simply three aspects of a single self-system, but rather three separate systems
with different identity properties, loci of agency, and motivational concerns
(Sedikides & Brewer, 2001). Brewer and Gardner (1996) also noted that,
analogous to the inclusion versus differentiation motives that determine
optimal collective identities, opposing needs for differentiation and assimila-
tion may also be involved in individual and relational selves to determine
optimal identities at those levels as well (see also Brewer & Roccas, 2001).
This extension of the opposing motives model is depicted in Table 2.2.
At the collective level, the conflict is between belonging and inclusion on
the one hand, and separation and distinctiveness on the other. At the
individual level, the needs are expressed in the opposition between
the desire for similarity on the one hand and the need for uniqueness on
the other (Snyder & Fromkin, 1980; see also Hornsey & Jetten, 2004). The
distinction between inclusiveness–distinctiveness and similarity–uniqueness
is subtle but important. Similarity refers to the degree or extent of overlap
between one’s own characteristics (attributes, attitudes, etc.) and those of
another individual or a group prototype. Inclusion refers to the number of
others with whom one shares a collective bond (which may be based on a
single shared characteristic).
At the interpersonal (relational) level, the tension is represented by
conflicts between the need for autonomy and the need for interdependence
and intimacy with specific others. The literature on romantic attachments,
in particular, acknowledges that close relationships are characterized by
tension between intimacy and autonomy. Ideal relationships serve both
needs, and secure attachment figures provide for both supportive nurtur-
ance and autonomy and initiative (Shaver & Mikulincer, 2007). Insecure
attachment can be engendered by overprotective nurturance as well as by
rejection or unresponsiveness.
The extended optimal distinctiveness model views the individual social
self as a complex of regulatory systems. At each level, the person must
achieve some optimal balance between these conflicting motives for defin-
ing self in relation to others. In order to survive and function effectively,
each person must maintain an optimal level of self-integrity, achieve and
Table 2.2 Opposing drives and levels of self-representation
Level of self
Motivational pole
Differentiation Assimilation
Individual Uniqueness Similarity
Relational Autonomy Intimacy/interdependence
Collective Separation Inclusion/belonging
Adapted from Brewer and Roccas (2001; Table 12.1, p. 223).
Optimal Distinctiveness Theory 103
sustain a sufficient number of close relationships that meet competing needs
for intimacy and autonomy, and maintain secure inclusion in optimally
distinctive groups. Fulfilling each of these needs requires the basic compo-
nents of a regulatory system (Carver & Scheier, 1982; Miller et al., 1960),
including an assessment function that monitors and registers the individual’s
current state of need satisfaction, a comparator function that evaluates the
current state against an ideal or goal state, and an activation (monitoring and
coping) function that responds to discrepancies detected by the comparator
and remains active until the discrepancy is reduced or eliminated
(Leonardelli, 2010; Pickett & Gardner, 2005). Just as hunger and thirst
respond to different cues of physiological deprivation and activate different
cravings and goal representations, the relational and social self are regulated
by different cues to satisfaction and deprivation. Each system is sensitive to
different states of social connectedness (e.g., What is my current level of
intimacy in my relationship with this person? Am I feeling too different
from others in this social context? Are the boundaries of my group being
maintained?), and the individual must be prepared to respond with appro-
priate corrective action when assessed states of distinctiveness and inclusion
deviate from optimal balance at any level of the social self.
6.2. Establishing motivational primacy
The idea that distinct levels of self-representation exist within the individual
has inspired some researchers to ask the question of which level of self is
motivationally primary (see Gaertner et al., 1999, 2002). In other words, are
there self-representations that individuals seem to care more about and that
are more central to directing thoughts, behaviors, and actions? Gaertner and
his colleagues have offered three hypotheses for which level of self might
be motivationally primary: primacy of the individual self, primacy of the
collective self, and situational-primacy (the idea that primacy may be
determined by which level of self is salient within a particular social context;
Gaertner et al., 1999, 2002).
To date, the empirical research that has attempted to test these hypoth-
eses has assessed primacy primarily by examining which self individuals are
more likely to protect under conditions of threat. Alternatively, the research
examined which self are individuals more prone to actively enhance. Using
this criterion for motivational primacy, researchers have concluded that the
individual self is motivationally primary, as participants appeared to be more
likely to protect the individual self from threat and enhance the individual
self relative to the collective self (e.g., Gaertner et al., 2002). However, this
evidence can also be interpreted as support for the fragility and insecurity of
the individual self rather than its primacy. Furthermore, the fact that
individuals appear to react more strongly to insults and threats to the
individual self than the collective self does not imply that people are
104 Geoffrey J. Leonardelli et al.
generally more likely to pursue motives associated with the individual
self than the relational or collective self, or that goals associated
with the individual self are more likely to spur action than goals associated
with the other selves. In sum, the research that has been used as evidence for
motivational primacy of the individual self (e.g., Gaertner et al., 1999, 2002)
has failed to examine actual motivation or goal pursuit.
Thus, the issue of which level of self is motivationally primary is by no
means resolved, and, from our perspective, the more interesting question is
how the needs for inclusion and differentiation might play a role in deter-
mining the primacy or salience of a given level of self-representation. In the
original description of optimal distinctiveness theory, Brewer (1991) put
forth the idea that identification and loyalty should be strongest for those
group identities that are best able to satisfy both needs simultaneously.
An extension of this idea is that individuals might activate levels of self-
representation that are, within a given social context, more successful at
resolving the tension between the motivational poles that characterize that
level of self-representation (see Table 2.2). For example, if a person has not
successfully managed to resolve the needs for autonomy and relatedness in
his or her primary interpersonal relationships, this person might be more
satisfied at defining the self at the collective level to the extent that there
are collective identities in which the needs for inclusion and distinctiveness
are being successfully met. Or alternatively, if the needs for similarity and
uniqueness are not well balanced at the level of the individual self, a person
might use the collective self as a more chronic basis for self-definition.
In short, we offer an additional hypothesis and propose that the primacy
of a given level of self-representation may be determined by how satisfied
individuals feel at that level of self-representation and that satisfaction should
be determined, at least in part, by the extent to which the needs for
inclusion and differentiation are being met.
6.3. The role of social recognition
One issue that has not been discussed in much detail in this chapter is the
role that social recognition plays in the satisfaction of the needs for inclusion
and differentiation. Among psychologists, one of the best-known concepts
emerging from the symbolic interactionist movement is the looking-glass
self. Cooley (1902) coined this term to refer to the idea that people perceive
themselves through the eyes of others. In other words, how we view
ourselves is shaped by how we think we appear to others and how we
think others judge us. Not only do people rely on others to help define the
self, but they also find it important to communicate their self-conceptions to
others (e.g., Wicklund & Gollwitzer, 1982). Research on collective self-
verification (Chen et al., 2004; Gomez et al., 2009) indicates that people are
motivated to have their views of their collective self verified by others and
Optimal Distinctiveness Theory 105
that this is particularly the case when the collective self-views are strongly
held and when group identification is high. Finally, the importance of social
recognition is highlighted by recent research examining the concept of
group-identity completion (Ledgerwood et al., 2007). Ledgerwood et al.
found evidence that group members seek to communicate their group
identity to others through socially recognized symbols, just as individuals
self-symbolize to communicate personal identities. Furthermore, these
symbols of group identity appear to take on heightened importance and
value when group members experience a threat to their collective identity
(i.e., when the group is not being adequately recognized).
This research suggests that an important component to satisfaction of the
needs for inclusion and differentiation may be having other people recog-
nize and verify one’s inclusionary status or the distinctiveness of one’s
group. Prior research testing optimal distinctiveness theory has generally
not included conditions where verification or recognition has been
manipulated. However, we predict that social verification of collective
self-views is an important component of need satisfaction and that under
conditions of threat, people will work especially hard at attaining this
recognition—for example, through the acquisition of group symbols or
explicit attempts to manipulate others’ views (Swann, 1987). Thus, one
avenue for future research is to examine need satisfaction within a truly
social context so that the process of how individuals negotiate their collec-
tive identities with others can be studied.
7. Conclusion
Optimal distinctiveness theory (Brewer, 1991) proposes that indivi-
duals have two fundamental and competing human needs—the need for
inclusion and the need for differentiation—that can be met by membership
in moderately inclusive (optimally distinct) groups. This paper demonstrates
that the needs for inclusion and differentiation matter to the psychology of
group life in terms of how individuals identify with groups, perceive them,
and compete on behalf of their group memberships. We argue that these
motives have their origin in an evolutionary past in which humans’ primary
strategy for survival involved intense interdependence in distinct, bounded
social groups. Security and survival depended on inclusion in stable, clearly
differentiated social groups. As a consequence of our evolutionary history,
our sense of personal security and certainty are maximized in the context of
shared in-group membership and clear in-group–out-group distinctions.
Human psychology was not forged under the conditions of global
interdependence that characterize today’s complex social world. The chal-
lenge now is to learn to accommodate the human need for distinct in-group
106 Geoffrey J. Leonardelli et al.
identities with the necessity for intergroup acceptance and cooperation to
solve contemporary world problems. A better understanding of the oppos-
ing motives that underlie social identity may suggest alternative ways to
meet these fundamental psychological needs in order to reap the benefits of
in-group belonging without the social costs of intergroup discrimination
and conflict.
ACKNOWLEDGMENTS
This work was supported by a standard research grant to the first author from Canada’s Social
Sciences and Humanities Research Council. Much of the program of research reported in
this chapter was supported by grant funding from the National Science Foundation. We
thank Miles Hewstone for his helpful comments on a previous version of this draft.
REFERENCES
Abrams, D. (1994a). Political distinctiveness: An identity optimising approach. European
Journal of Social Psychology,24(3), 357–365.
Abrams, D. (1994b). Social self-regulation. Personality and Social Psychology Bulletin,20(5),
473–483.
Abrams, D. (2009). Social identity on a national scale: Optimal distinctiveness and young
people’s self-expression through musical preference. Group Processes and Intergroup Rela-
tions,12(3), 303–317.
Andrijiw, A., & Hyatt, C. (2009). Using optimal distinctiveness theory to understand identifi-
cation with a nonlocal professional hockey team. Journal of Sport Management,23(2),
156–181.
Badea, C., Jetten, J., Czukor, G., & Askevis-Leherpeux, F. (2010). The bases of identifica-
tion: When optimal distinctiveness needs face social identity threat. British Journal of Social
Psychology 49(1), 21–41.
Baumeister, R. F., & Leary, M. R. (1995). The need to belong: Desire for interpersonal
attachments as a fundamental human motivation. Psychological Bulletin,117(3), 497–529.
Bearman, P. S., & Bru
¨ckner, H. (2001). Promising the future: Virginity pledges and first
intercourse. American Journal of Sociology,106(4), 859–912.
Bettencourt, B. A., Miller, N., & Hume, D. L. (1999). Effects of numerical representation
within cooperative settings: Examining the role of salience in in-group favouritism.
British Journal of Social Psychology,38(3), 265–287.
Billig, M., & Tajfel, H. (1973). Social categorization and similarly in intergroup behavior.
European Journal of Social Psychology,3, 7–52.
Blanz, M., Mummendey, A., & Otten, S. (1995). Positive-negative asymmetry in social
discrimination: The impact of stimulus valence and size and status differentials on
intergroup evaluations. British Journal of Social Psychology,34(4), 409–419.
Bornstein, G., Crum, L., Wittenbraker, J., Harring, K., Insko, C. A., & Thibaut, J. (1983a).
On the measurement of social orientations in the minimal group paradigm. European
Journal of Social Psychology,13(4), 321–350.
Bornstein, G., Crum, L., Wittenbraker, J., Harring, K., Insko, C. A., & Thibaut, J. (1983b).
Reply to Turner’s comments. European Journal of Social Psychology,13(4), 369–381.
Bourhis, R. Y., Sachdev, I., & Gagnon, A. (1994). Intergroup research with the Tajfel
Matrices: Methodological notes. In M. P. Zanna & J. M. Olson (Eds.), The psychology of
prejudice: The Ontario symposium (Vol. 7, pp. 209–232). Hillsdale, NJ: Erlbaum.
Optimal Distinctiveness Theory 107
Brewer, M. B. (1991). The social self: On being the same and different at the same time.
Personality & Social Psychology Bulletin,17(5), 475–482.
Brewer, M. B. (1993a). Social identity, distinctiveness, and in-group homogeneity. Social
Cognition,11(1), 150–164.
Brewer, M. B. (1993b). The role of distinctiveness in social identity and group behaviour. In
M. A. Hogg & D. Abrams (Eds.), Group motivation: Social psychological perspectives
(pp. 1–16). Hertfordshire, England: Harvester Wheatsheaf.
Brewer, M. B. (1997). On the social origins of human nature. In S. A. Haslam & C. McGarty
(Eds.), The message of social psychology: Perspectives on mind in society. Malden, MA:
Blackwell.
Brewer, M. B. (1999). The psychology of prejudice: Ingroup love or outgroup hate? Journal
of Social Issues,55(3), 429–444.
Brewer, M. B. (2003). Optimal distinctiveness, social identity, and the self. In M. R. Leary &
J. P. Tangney (Eds.), Handbook of self and identity (pp. 480–491). New York, NY:
Guilford Press.
Brewer, M. B., & Caporael, L. (2006). An evolutionary perspective on social identity:
Revisiting groups. In M. Schaller, J. Simpson, & D. Kenrick (Eds.), Evolution and social
psychology (pp. 143–161). New York: Psychology Press.
Brewer, M. B., & Gardner, W. (1996). Who is this ‘‘We’’? Levels of collective identity and
self representations. Journal of Personality and Social Psychology,71(1), 83–93.
Brewer, M. B., & Roccas, S. (2001). Individual values, social identity, and optimal distinc-
tiveness. In C. Sedikides & M. B. Brewer (Eds.), Individual self, relational self, collective self
(pp. 219–237). Philadelphia, PA: Psychology Press/Taylor & Francis.
Brewer, M. B., & Silver, M. D. (2000). Group distinctiveness, social identification, and
collective mobilization. In S. Stryker, T. J. Owens, & R. W. White (Eds.), Self, identity,
and social movements (pp. 153–171). Minneapolis, MN: University of Minnesota Press.
Brewer, M. B., & Weber, J. G. (1994). Self-evaluation effects of interpersonal versus
intergroup social comparison. Journal of Personality and Social Psychology,66(2), 268–275.
Brewer, M. B., Manzi, J. M., & Shaw, J. S. (1993). In-group identification as a function of
depersonalization, distinctiveness, and status. Psychological Science,4(2), 88–92.
Brown, R., & Abrams, D. (1986). The effects of intergroup similarity and goal interdepen-
dence on intergroup attitudes and task performance. Journal of Experimental Social Psychology,
22, 78–92.
Brown, R. J., & Turner, J. C. (1981). Interpersonal and intergroup behavior. In J. C. Turner
& H. Giles (Eds.), Intergroup behaviour (pp. 33–65). Oxford, England: Blackwell.
Burris, C. T., & Jackson, L. M. (2000). Social identity and the true believer: Responses
to threatened self-stereotypes among the intrinsically religious. British Journal of Social
Psychology,39, 257–278.
Campbell, J. D. (1986). Similarity and uniqueness: The effects of attribute type, relevance,
and individual differences in self-esteem and depression. Journal of Personality and Social
Psychology,59, 281–294.
Caporael, L. R. (1997). The evolution of truly social cognition: The core configurations
model. Personality and Social Psychology Review,1(4), 276–298.
Carver, C. S., & Scheier, M. F. (1982). Control-theory—A useful conceptual-framework
for personality—Social, clinical, and health psychology. Psychological Bulletin,92(1),
111–135.
Chen, S., Chen, K. Y., & Shaw, L. (2004). Self-verification motives at the collective level of
self-definition. Journal of Personality and Social Psychology,86, 77–94.
Codol, J.-P. (1975). On the so-called ‘‘superior conformity of the self’’ behavior: Twenty
experimental investigations. European Journal of Social Psychology,5(4), 457–501.
Cooley, C. H. (1902). Human nature and the social order. New York: Scribner.
108 Geoffrey J. Leonardelli et al.
Correll, J., & Park, B. (2005). A model of the ingroup as a social resource. Personality and
Social Psychology Review,9, 341–359.
Cross, S. E., & Madson, L. (1997). Models of the self: Self-construals and gender. Psychological
Bulletin,122, 5–37.
Diehl, M. (1988). Social identity and minimal groups: The effects of interpersonal and
intergroup attitudinal similarity on intergroup discrimination. British Journal of Social
Psychology,27, 289–300.
Dimmock, J. A. (2009). The influence of assimilation and differentiation needs on sport team
preferences: The quest for optimal distinctiveness. International Journal of Sport Psychology,
40, 392–402.
Ellemers, N., Doosje, B. J., Van Knippenberg, A., & Wilke, H. (1992). Status protection in
high status minority groups. European Journal of Social Psychology,22(2), 123–140.
Ellemers, N., Kortekaas, P., & Ouwerkerk, J. W. (1999). Self-categorisation, commitment
to the group and group self-esteem as related but distinct aspects of social identity.
European Journal of Social Psychology,29(2–3), 371–389.
Ellemers, N., & Van Rijswijk, W. (1997). Identity needs versus social opportunities: The use
of group-level and individual-level identity management strategies. Social Psychology
Quarterly,60(1), 52–65.
Feather, N. T. (1995). National identification and ingroup bias in majority and minority
groups: A field study. Australian Journal of Psychology,47(3), 129–136.
Ferguson, R., Gever, M., Minh-ha, T. T., & West, C. (1990). Out there: Marginalization and
contemporary cultures. New York, NY: The New Museum of Contemporary Art.
Fiske, S. T. (2004). Social beings: A core motives approach to social psychology. New York: Wiley.
Gaertner, L., Sedikides, C., & Graetz, K. (1999). In search of self-definition: Motivational
primacy of the individual self, motivational primacy of the collective self, or contextual
primacy? Journal of Personality and Social Psychology,76(1), 5–18.
Gaertner, L., Sedikides, C., Vevea, J. L., & Iuzzini, J. (2002). The ‘I’, the ‘we’, and the
‘when’: A meta-analysis of motivational primacy in self-definition. Journal of Personality
and Social Psychology,83(3), 574–591.
Gerard, H. B., & Hoyt, M. F. (1974). Distinctiveness of social categorization and attitude
toward ingroup members. Journal of Personality and Social Psychology,29(6), 836–842.
Gomez, A., Seyle, D. C., Huici, C., & Swann, W. B. (2009). Can self-verification strivings
fully transcend the self-other barrier? Seeking verification of ingroup identities. Journal of
Personality and Social Psychology,97, 1021–1044.
Grann, D. (2009). The lost city of Z. A tale of deadly obsession in the Amazon. New York, NY:
Doubleday.
Griesinger, D. W., & Livingston, J. W. (1973). Toward a model of interpersonal orientation
in experimental games. Behavioral Science,18, 173–188.
Hewstone, M., Rubin, M., & Willis, H. (2002). Intergroup bias. Annual Review of Psychology,
53(1), 575–604.
Hogg, M. A. (2007). Uncertainty-identity theory. In M. P. Zanna (Ed.), Advances in
experimental social psychology (Vol. 39, pp. 69–126). San Diego, CA: Elsevier.
Hogg, M. A., & Abrams, D. (1988). Social identifications: A social psychology of intergroup
relations and group processes. London: Routledge.
Hogg, M. A., & Turner, J. C. (1987). Intergroup behaviour, self-stereotyping and the
salience of social categories. British Journal of Social Psychology,26, 325–340.
Hornsey, M. J., & Hogg, M. A. (1999). Subgroup differentiation as a response to an overly-
inclusive group: A test of optimal distinctiveness theory. European Journal of Social
Psychology,29(4), 543–550.
Hornsey, M. J., & Jetten, J. (2004). The individual within the group: Balancing the need to
belong with the need to be different. Personality & Social Psychology Review,8(3), 248–264.
Optimal Distinctiveness Theory 109
Imhoff, R., & Erb, H.-P. (2009). What Motivates Nonconformity? Uniqueness Seeking
Blocks Majority Influence. Personality and Social Psychology Bulletin,35(3), 309–320.
Jetten, J., Branscombe, N., & Spears, R. (2002). On being peripheral: Effects of identity
insecurity on personal and collective self-esteem. European Journal of Social Psychology,32,
105–123.
Jetten, J., Spears, R., & Manstead, A. S. R. (1996). Intergroup norms and intergroup
discrimination: Distinctive self-categorization and social identity effects. Journal of Person-
ality and Social Psychology,71, 1222–1233.
Jetten, J., Spears, R., & Manstead, A. S. R. (2001). Similarity as a source of differentiation:
The role of group identification. European Journal of Social Psychology,31, 621–640.
Jetten, J., Spears, R., & Postmes, T. (2004). Intergroup distinctiveness and differentiation: A
meta-analytic integration. Journal of Personality and Social Psychology,86, 862–879.
Jost, J. T., & Banaji, M. R. (1994). The role of stereotyping in system-justification and the
production of false consciousness. British Journal of Social Psychology. Special Stereotypes:
Structure, Function and Process,33(1), 1–27.
Kahney, L. (2004/2006). The cult of Mac. San Francisco: No Starch Press.
Krueger, J., & Clement, R. W. (1994). The truly false consensus effect: An ineradicable and
egocentric bias in social perception. Journal of Personality and Social Psychology,67, 596–610.
Landau, M. J., Greenberg, J., Sullivan, D., Routledge, C., & Arndt, J. (2009). The protective
identity: Evidence that mortality salience heightens the clarity and coherence of the self-
concept. Journal of Experimental Social Psychology,45, 796–807.
Lau, R. R. (1989). Individual and contextual influences on group identification. Social
Psychology Quarterly,52, 220–231.
Ledgerwood, A., Liviatan, I., & Carnevale, P. J. (2007). Group identity completion and the
symbolic value of property. Psychological Science,18, 873–878.
Lemaine, G. (1974). Social differentiation and social originality. European Journal of Social
Psychologv,4, 17–52.
Leonardelli, G. J. (1998). The motivational underpinnings of social discrimination: A test of the self-
esteem hypothesis. Unpublished master’s thesis, The Ohio State University, Columbus.
Leonardelli, G. J. (2002). Smaller can be better: Minority affirmation in intergroup relations.
Unpublished Doctoral Dissertation, The Ohio State University, Columbus.
Leonardelli, G. J. (2006). Predicting relative size preference: Comparing majority preference, optimal
distinctiveness, and affect intensifier models. Unpublished manuscript, University of Toronto,
Canada.
Leonardelli, G. J. (2010). Membership maintenance model of group member behavior. University of
Toronto, ON, Canada: Rotman School of Management.
Leonardelli, G. J., & Brewer, M. B. (2001). Minority and majority discrimination: When
and why. Journal of Experimental Social Psychology,37(6), 468–485.
Leonardelli, G. J., & Galinsky, A. D. (2010). Optimal distinctiveness and collective self-affirmation:
The meaning of ingroup favoritism for numerical minorities. Canada: Rotman School of
Management, University of Toronto (Under review).
Leonardelli, G. J., & Pickett, C. L. (2009). Need satisfaction correlation data. Canada:
Rotman School of Management, University of Toronto.
Levine, J. M., & Moreland, R. L. (1998). Small groups. In D. T. Gilbert, S. T. Fiske, &
G. Lindsey (Eds.), The handbook of social psychology (4th ed. Vol. 2, pp. 415–469). New
York, NY: McGraw-Hill.
Liebrand, W. B. G. (1984). The effect of social motives, communication and group size on
behavior in an N-person multi-stage mixed-motive game. European Journal of Social
Psychology,14, 239–264.
Lu
¨cken, M., & Simon, B. (2005). Cognitive and affective experiences of minority and
majority members: The role of group size, status, and power. Journal of Experimental Social
Psychology,41, 396–413.
110 Geoffrey J. Leonardelli et al.
Luhtanen, R., & Crocker, J. (1992). A collective self-esteem scale: Self-evaluation of one’s
social identity. Personality and Social Psychology Bulletin,18(3), 302–318.
Markus, H., & Kitayama, S. (1991). Culture and the self: Implications for cognition,
emotion, and motivation. Psychological Review,98, 224–253.
Markus, H., & Kunda, Z. (1986). Stability and malleability in the self-concept in the
perception of others. Journal of Personality and Social Psychology,51, 858–866.
Maslach, C. (1974). Social and personal bases of individuation. Journal of Personatity and Social
Psychology,29, 411–425.
Maslow, A. H. (1943). A theory of human motivation. Psychological Review,50, 370–396.
McGuire, W. J., & McGuire, C. V. (1988). Content and process in the experience of the self.
In L. Berkowitz (Ed.), Advances in experimental social psychology (Vol. 21, pp. 97–144). San
Diego, CA: Academic Press, Inc.
McQueen, A., & Klein, W. M. P. (2006). Experimental manipulations of self-affirmation:
A systematic review. Self and Identity,5(4), 289–354.
Messick, D. M., & McClintock, C. G. (1968). Motivational basis of choice in experimental
games. Journal of Experimental Social Psychology,4, 1–25.
Miller, G. A., Galanter, E., & Pribram, K. H. (1960). The unit of analysis. In G. A. Miller,
E. Galanter, & K. H. Pribram (Eds.), Plans and the structure of behavior (pp. 21–39). New
York, NY: Henry Holt and Co., Inc.
Moons, W. G., Leonard, D. J., Mackie, D. M., & Smith, E. R. (2009). I feel our pain:
Antecedents and consequences of emotional self-stereotyping. Journal of Experimental
Social Psychology,45, 760–769.
Moreland, R. L., & Levine, J. M. (1982). Socialization in small groups: Temporal changes in
individual-group relations. In L. Berkowitz (Ed.), Advances in experimental social psychology
(Vol. 15, pp. 137–192). New York: Academic Press.
Moreland, R. L., & Levine, J. M. (2002). Socialization and trust in work groups. Group
Processes and Intergroup Relations,5, 185–201.
Moreland, R. L., Levine, J. M., & McMinn, J. G. (2001). Self-categorization and work
group socialization. In M. Hogg & D. Terry (Eds.), Social identity processes in organizational
contexts (pp. 87–100). Philadelphia: Psychology Press.
Mullen, B. (1991). Group composition, salience, and cognitive representations: The phe-
nomenology of being in a group. Journal of Experimental Social Psychology,27(4), 297–323.
Mullen, B., Brown, R., & Smith, C. (1992). Ingroup bias as a function of salience, relevance,
and status: An integration. European Journal of Social Psychology,22(2), 103–122.
Mummendey, A., & Schreiber, H. J. (1984). Social comparison, similarity and ingroup
favouritism: A replication. European Journal of Social Psychology,14, 231–233.
Nelson, L. J., & Miller, D. T. (1995). The distinctiveness effect in social categorization—you
are what makes you unusual. Psychological Science,6(4), 246–249.
Noel, J. G., Wann, D. L., & Branscombe, N. R. (1995). Peripheral ingroup membership
status and public negativity toward outgroups. Journal of Personality and Social Psychology,
68(1), 127–137.
Oakes, P. J., Haslam, S. A., & Turner, J. C. (1998). The role of prototypicality in group
influence and cohesion: Contextual variation in the graded structure of social categories.
In S. Worchel, J. F. Morales, D. Paez, & J.-C. Deschamps (Eds.), Social identity: Interna-
tional perspectives. London, UK & Newbury Park, USA: Sage.
Park, B., & Judd, C. M. (1990). Measures and models of perceived group variability. Journal
of Personality and Social Psychology,59, 173–191.
Pickett, C. L., Bonner, B. L., & Coleman, J. M. (2002a). Motivated self-stereotyping:
Heightened assimilation and differentiation needs result in increased levels of positive
and negative self-stereotyping. Journal of Personality and Social Psychology,82(4), 543–562.
Pickett, C. L., & Brewer, M. B. (2001). Assimilation and differentiation needs as motiva-
tional determinants of perceived in-group and out-group homogeneity. Journal of Experi-
mental Social Psychology,37(4), 341–348.
Optimal Distinctiveness Theory 111
Pickett, C. L., & Gardner, W. L. (2005). The social monitoring system: Enhanced sensitivity
to social cues as an adaptive response to social exclusion. In K. Williams, J. Forgas, &
W. von Hippel (Eds.), The social outcast: Ostracism, social exclusion, rejection, and bullying.
New York: Psychology Press.
Pickett, C. L., & Leonardelli, G. J. (2006). Using collective identities for assimilation and
differentiation. In T. Postmes & J. Jetten (Eds.), Individuality and the group: Advances in
social identity (pp. 56–73). Thousand Oaks, CA: Sage.
Pickett, C. L., Silver, M. D., & Brewer, M. B. (2002b). The impact of assimilation and
differentiation needs on perceived group importance and judgments of ingroup size.
Personality and Social Psychology Bulletin,28(4), 546–558.
Sachdev, I., & Bourhis, R. Y. (1984). Minimal majorities and minorities. European Journal of
Social Psychology,14(1), 35–52.
Sachdev, I., & Bourhis, R. Y. (1991). Power and status differentials in minority and majority
group relations. European Journal of Social Psychology,21(1), 1–24.
Salancik, J. R. (1974). Inference of one’s attitude from behavior recalled under linguistically
manipulated cognitive sets. Journal of Experimental Social Psychology,10(5), 415–427.
Sedikides, C., & Brewer, M. B. (2001). Individual self, relational self, collective self. Philadelphia,
PA: Psychology Press/Taylor & Francis.
Shaver, P. R., & Mikulincer, M. (2007). Attachment theory and research: Core concepts,
basic principles, conceptual bridges. In A. Kruglanski & E. T. Higgins (Eds.), Social
psychology: Handbook of basic principles (2nd ed.). New York: Guilford.
Sherman, D. K., & Cohen, G. L. (2006). The psychology of self-defense: Self-affirmation
theory. In M. Zanna (Ed.), Advances in experimental social psychology (Vol. 38,
pp. 183–242). San Diego, CA: Elsevier.
Sherman, S. J., Presson, C. C., & Chassin, L. (1984). Mechanisms underlying the false
consensus effect: The special role of threats to self. Personality and Social Psychology Bulletin,
10, 127–138.
Simon, B., Aufderheide, B., & Kampmeier, C. (2001). The social psychology of minority-
majority relations. In R. Brown & S. Gaertner (Eds.), Blackwell handbook of social psychol-
ogy: Intergroup processes (pp. 303–323). Malden, MA: Blackwell.
Simon, B., & Brown, R. (1987). Perceived intragroup homogeneity in minority-majority
contexts. Journal of Personality and Social Psychology,53(4), 703–711.
Simon, B., & Hamilton, D. L. (1994). Self-stereotyping and social context: The effects of
relative in-group size and in-group status. Journal of Personality and Social Psychology,66(4),
699–711.
Simon, L., Greenberg, J., Arndt, J., Pyszczynski, T., Clement, R., & Solomon, S. (1997).
Perceived consensus, uniqueness, and terror management: Compensatory responses to
threats to inclusion and distinctiveness following mortality salience. Personality and Social
Psychology Bulletin,23(10), 1055–1065.
Snyder, C. R., & Fromkin, H. L. (1980). Uniqueness: The human pursuit of difference. New
York, NY: Plenum Press.
Sorrentino, R. M., Seligman, C., & Battista, M. E. (2007). Optimal distinctiveness, values,
and uncertainty orientation: Individual differences on perceptions of self and group
identity. Self and Identity,6(4), 322–339.
Spears, R., Doosje, B., & Ellemers, N. (1997). Self-stereotyping in the face of threats to
group status and distinctiveness: The role of group identification. Personality and Social
Psychology Bulletin,23, 538–553.
Stapel, D. A., & Marx, D. M. (2007). Distinctiveness is key: How different types of self-other
similarity moderate social comparison effects. Personality and Social Psychology Bulletin,33,
439–448.
Steele, C. M. (1988). The psychology of self-affirmation: Sustaining the integrity of the self.
In L. Berkowitz (Ed.), Advances in experimental social psychology (Vol. 21, pp. 261–302). San
Diego, CA: Academic Press, Inc.
112 Geoffrey J. Leonardelli et al.
Suls, J., Wan, C. K., & Sanders, G. S. (1988). False consensus and false uniqueness in
estimating the prevalence of health protective behaviors. Journal of Applied Social Psychol-
ogy,18, 66–79.
Swann, W. B. Jr. (1987). Identity negotiation: Where two roads meet. Journal of Personality
and Social Psychology,53, 1038–1051.
Tajfel, H. (1981). Human groups and social categories. Cambridge, England: Cambridge
University Press.
Tajfel, H., Billig, M. G., Bundy, R. P., & Flament, C. (1971). Social categorization and
intergroup behaviour. European Journal of Social Psychology,1(2), 149–178.
Tajfel, H., & Turner, J. C. (1979). An integrative theory of intergroup conflict. In W. Austin
& S. Worchel (Eds.), Social psychology of intergroup relations (pp. 33–47). Chicago: Nelson.
Timor, Y., & Katz-Navon, T. (2008). Being the same and different: A model explaining new
product adoption. Journal of Consumer Behaviour,7, 249–262.
Turner, J. C., Hogg, M. A., Oakes, P. J., Reicher, S. D., & Wetherell, M. S. (1987).
Rediscovering the social group: Self-categorization theory. Oxford, UK: Blackwell.
Vignoles, V. L., Regalia, C., Manzi, C., Golledge, J., & Scabini, E. (2006). Beyond self-
esteem: Influence of multiple motives on identity construction. Journal of Personality and
Social Psychology,90(2), 308–333.
White, J. B., & Langer, E. J. (1999). Horizontal hostility: Relations between similar minority
groups. Journal of Social Issues,55, 537–560.
Wicklund, R. A., & Gollwitzer, P. M. (1982). Symbolic self-completion. Hillsdale, NJ:
Lawrence Erlbaum.
Zhong, C.-B., Phillips, K. W., Leonardelli, G. J., & Galinsky, A. D. (2008). Negational
categorization and intergroup behavior. Personality and Social Psychology Bulletin,34(6),
793–806.
Ziller, R. C. (1964). Individuation and socialization. Human Relations,17, 341–360.
Optimal Distinctiveness Theory 113
