Tom Postmes

Toward an integrative Social Identity model of Collective Action: A quantitative research synthesis of three socio-psychological perspectives.

An integrative social identity model of collective action (SIMCA) is developed that incorporates 3 socio-psychological perspectives on collective action. Three meta-analyses synthesized a total of 182 effects of perceived injustice, efficacy, and identity on collective action (corresponding to these socio-psychological perspectives). Results showed that, in isolation, all 3 predictors had medium-sized (and causal) effects. Moreover, results showed the importance of social identity in predicting collective action by supporting SIMCAs key predictions that (a) affective injustice and politicized identity produced stronger effects than those of non-affective injustice and non-politicized identity; (b) identity predicted collective action against both incidental and structural disadvantages, whereas injustice and efficacy predicted collective action against incidental disadvantages better than against structural disadvantages; (c) all 3 predictors had unique medium-sized effects on collective action when controlling for between-predictor covariance; and (d) identity bridged the injustice and efficacy explanations of collective action. Results also showed more support for SIMCA than for alternative models reflecting previous attempts at theoretical integration. The authors discuss key implications for theory, practice, future research, and further integration of social and psychological perspectives on collective action.

Breaching or Building Social Boundaries? SIDE-Effects of Computer-Mediated Communication

Computer-mediated communication (CMC) is sometimes heralded for its power to break down social boundaries and to liberate individuals from social influence, group pressure, and status and power differentials that characterize much face-to-face interaction. We review research conducted within the framework of the social identity model of deindividuation effects (SIDE) demonstrating that this is not always the case. When communicators share a common social identity, they appear to be more susceptible to group influence, social attraction, stereotyping, gender typing, and discrimination in anonymous CMC. Although CMC gives us the opportunity to traverse social boundaries, paradoxically, it can also afford these boundaries greater power, especially when they define self- and group identity.

A Social Identity Model of Deindividuation Phenomena

This chapter challenges traditional models of deindividuation. These are based on the assumption that such factors as immersion in a group and anonymity lead to a loss of selfhood and hence of control over behaviour. We argue that such models depend upon an individualistic conception of the self, viewed as a unitary construct referring to that which makes individuals unique. This is rejected in favour of the idea that self can be defined at various different levels including the categorical self as well as the personal self. Hence a social identity model of deindividuation (SIDE) is outlined. Evidence is presented to show that deindividuation manipulations gain effect, firstly, through the ways in which they affect the salience of social identity (and hence conformity to categorical norms) and, secondly, through their effects upon strategic considerations relating to the expression of social identities. We conclude that the classic deindividuation paradigm of anonymity within a social group, far from lead...

The Consequences of Perceived Discrimination for Psychological Well-Being: A Meta-Analytic Review

In 2 meta-analyses, we examined the relationship between perceived discrimination and psychological well-being and tested a number of moderators of that relationship. In Meta-Analysis 1 (328 independent effect sizes, N = 144,246), we examined correlational data measuring both perceived discrimination and psychological well-being (e.g., self-esteem, depression, anxiety, psychological distress, life satisfaction). Using a random-effects model, the mean weighted effect size was significantly negative, indicating harm (r = -.23). Effect sizes were larger for disadvantaged groups (r = -.24) compared to advantaged groups (r = -.10), larger for children compared to adults, larger for perceptions of personal discrimination compared to group discrimination, and weaker for racism and sexism compared to other stigmas. The negative relationship was significant across different operationalizations of well-being but was somewhat weaker for positive outcomes (e.g., self-esteem, positive affect) than for negative outcomes (e.g., depression, anxiety, negative affect). Importantly, the effect size was significantly negative even in longitudinal studies that controlled for prior levels of well-being (r = -.15). In Meta-Analysis 2 (54 independent effect sizes, N = 2,640), we examined experimental data from studies manipulating perceptions of discrimination and measuring well-being. We found that the effect of discrimination on well-being was significantly negative for studies that manipulated general perceptions of discrimination (d = -.25), but effects did not differ from 0 when attributions to discrimination for a specific negative event were compared to personal attributions (d = .06). Overall, results support the idea that the pervasiveness of perceived discrimination is fundamental to its harmful effects on psychological well-being.

Social Influence in Computer-Mediated Communication: The Effects of Anonymity on Group Behavior

Two studies examined hypotheses derived from a Social Identity model of Deindividuation Effects (SIDE) as applied to social influence in computer-mediated communication (CMC) in groups. This model predicts that anonymity can increase social influence if a common group identity is salient. In a first study, group members were primed with a certain type of social behavior (efficiency vs. prosocial norms). Consistent with the model, anonymous groups displayed prime-consistent behavior in their task solutions, whereas identifiable groups did not. This suggests that the primed norm took root in anonymous groups to a greater extent than in identifiable groups. A second study replicated this effect and showed that nonprimed group members conformed to the behavior of primed members, but only when anonymous, suggesting that the primed norm was socially transmitted within the group. Implications for social influence in small groups are discussed.

Quality of decision making and group norms

Two studies investigated the impact of group norms for maintaining consensus versus norms for critical thought on group decisions in a modification of the biased sampling paradigm (G. Stasser & W. Titus, 1985). Both studies showed that critical norms improved the quality of decisions, whereas consensus norms did not. This effect appeared to be mediated by the perceived value of shared and unshared information: Consensus norm groups valued shared information more highly than critical groups did, and valence was a good predictor of decision outcome. In addition, the 2nd study showed that the group norm manipulation has no impact on individual decisions, consistent with the assumption that this is a group effect. Results suggest that the content of group norms is an important factor influencing the quality of group decision-making processes and that the content of group norms may be related to the groups proneness for groupthink.

Seeing one thing and doing another : Contrast effects in automatic behavior

Research on automatic behavior demonstrates the ability of stereotypes to elicit stereotype-consistent behavior. Social judgment research proposes that whereas traits and stereotypes elicit assimilation, priming of exemplars can elicit judgmental contrast by evoking social comparisons. This research extends these findings by showing that priming exemplars can elicit behavioral contrast by evoking a social comparison. In Study 1, priming professor or supermodel stereotypes led, respectively, to more and fewer correct answers on a knowledge test (behavioral assimilation), but priming exemplars of these categories led to the reverse pattern (behavioral contrast). In Study 2, participants walked away faster after being primed with an elderly exemplar. In Study 3, the proposition that contrast effects reflect comparisons of the self with the exemplar was supported.

Social influence in small groups: An interactive model of social identity formation

The present paper tries to overcome the dualism of group-level vs. individualistic analysis of small group processes, by presenting a model of social identity formation that incorporates factors at both levels of analysis as well as their interaction. On the basis of prior theorising in the social identity tradition and a programme of research spanning several interactive group research paradigms, we suggest that within small groups a social identity can operate as a contextual given, which shapes the behaviour of individuals within the group, as much as the behaviour of individuals within the group can shape social identity. This proposal is supported by a programme of research into social influence within small interactive groups. This research explores deductive (top-down) processes through which existing identities influence group processes, but also shows a reciprocal influence through which intragroup discussion creates a sense of group identity in the apparent absence of any direct intergroup comparison (an inductive, or bottom-up, path). It is the interaction between these two forces that we believe is characteristic of the way in which small groups achieve a sense of social identity. Supporting this view, we describe research that suggests that processes of identity formation play a key role in decision making, productive collaboration, consensualisation, integrative negotiations, and the development of shared cognition.

Intergroup differentiation in computer-mediated communication: Effects of depersonalization.

Two studies examined intergroup discussions via computer-mediated communication systems. It was hypothesized that depersonalization, in comparison with individuated interaction, would increase the tendency for intergroup differentiation in attitudes and stereotypes, In Study 1, 24 groups communicated internationally over the Internet in a longitudinal design. Interacting groups, based in 2 different countries, were individuated versus partially unidentifiable, and thus depersonalized. Results indicate that depersonalized groups diverge, or bipolarize, when compared with individuated groups. A follow-up study demonstrated that under depersonalized conditions, individual differences are less salient, whereas group memberships are more salient. In addition, stereotypes were more salient in depersonalized conditions. Results support predictions derived from the social identity model of deindividuation effects.

Behavior Online: Does Anonymous Computer Communication Reduce Gender Inequality?

Two studies examined dominance and self-stereotyping in mixed-sex groups who had online discussions. Gender differences in dominance varied as a function of several contextual variables: individuation, the accessibility of gender stereotypes, and the fit between group task and stereotype. Results of the second study indicate that only when group members are depersonalized (anonymous and not individuated) does stereotype activation produce gender-stereotypic behavior. However, the nature of stereotypic behavior is moderated by the fit between group task and stereotypes, such that men dominate when the topic is masculine but not when it is feminine. These findings do not support suggestions that the anonymity offered by online communication would lead to equalization. Instead, results confirm predictions from a social identity model of deindividuation effects that social effects of anonymity and identifiability in (online) groups depend on contextual factors such as stereotype accessibility and fit.