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 SIMCA's 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

A social identity approach to trust: interpersonal perception, group membership and trusting behavior

Trusting behaviour involves relinquishing control over outcomes valuable to the self. Previous research suggests that interpersonal perceptions of trustworthiness are closely related to this behaviour. The present research suggests that the more proximal determinant of trusting behaviour is the expectation that the other will reciprocate. Based on the Social Identity model of Deindividuation Effects (SIDE) model, reciprocity expectations may be created by interpersonal perceptions of trustworthiness or a shared group membership. To investigate this, group membership and individual identifiability were experimentally manipulated (N = 139): When individuals were not identifiable, trusting behaviour was based on expectations of reciprocity inferred from group membership, not on perceived trustworthiness. In contrast, personal identifiability fostered perceptions of trustworthiness for both in- and out-group members. In this case interpersonal trustworthiness enhanced expectations of reciprocity, which in turn increased trusting behaviour. Copyright © 2005 John Wiley & Sons, Ltd

Private-public opinion discrepancy

In many Western societies there are rising concerns about increasing polarization in public debate. However, statistics on private attitudes paint a different picture: the average attitudes in societies are more moderate and remain rather stable over time. The present paper presents an agent-based model of how such discrepancies between public opinion and private attitudes develop at the scale of micro-societies. Based on social psychological theorizing, the model distinguishes between two types of agents: a) those seeking to gain or maintain a good reputation and status, and b) those seeking to promote group harmony by reaching consensus. We characterized these different types of agents by different decision rules for either voicing their opinion or remaining silent, based on the behavior of their proximal network. Results of the model simulations show that even when the private attitudes of the agents are held constant, publicly expressed opinions can oscillate and (depending on the reputational concerns of individual actors) situations can occur in which minorities as well as majorities are silenced. We conclude that the macro-level consequences of micro-level decisions to either voice an opinion or remain silent provide a foundation for better understanding how public opinions are shaped. Moreover, we discuss the conditions under which public opinion could be considered a good representation of private attitudes in a society