This article examines inductive processes of social identity formation, the bottom-up processes by which individual group members influence a social identity, integrating it with work on entitativity. Three studies tested the prediction that feelings of individual distinctiveness mediate the relation between inductive social identity formation and entitativity and that entitativity in turn predicts identification. The studies provided consistent support for this theoretical model over alternative models, using a range of different social groups and methods. Study 1 found support for the model in self-selected small groups. Study 2 supported it with a much broader set of groups that were not self-selected. Finally, Study 3 varied levels of inductive social identity formation systematically by varying group size and provided direct support for the hypothesized causal relations.

Research on in-group identification typically focuses on differences in individuals’ identification at the individual level of analysis. We take a multilevel approach, examining the emergence of group influence on identification in newly formed groups. In three studies, multilevel confirmatory factor analysis confirmed two dimensions of identification—self-definition and self-investment (Leach et al., 2008)—at both the individual and the group level. As expected, the group had greater influence on individuals’ identification the more group members interacted with each other. This was shown in experiments with varying amounts of real interaction (Study 1), in a longitudinal study of student project groups (Study 2), and in a longitudinal study that experimentally mimicked the development of online communities (Study 3). Together, these studies support a developmental model of identification at the group level that has implications for the understanding of social identity and small-group dynamics.

While the majority of people care about environmental quality, they keep engaging in carbon-intensive practices that exacerbate climate change. Can we expect humans to collectively change by themselves, from the bottom up? Social change is often initiated by minorities - individuals who challenge the status quo. The dominant literature paints a rather pessimistic picture about the ability of minorities to instigate change in the environmental domain: environmental activists, vegans, and other minority members often elicit social sanctions, thereby ironically reinforcing the majority's commitment to current, environmentally harmful norms. Recent findings, however, point towards more optimism: pro-environmental minorities can pave the way towards 'tipping points' and spontaneous social change. Policymakers can speed up this process by offering top-down support for minorities - by giving them 'voice'.

Community environmental initiatives are set up by community members to promote pro-environmental behaviours in their community. Community members involved in these initiatives are likely to behave more pro-environmentally. Yet, the question remains how to get community members involved. Previous findings suggest stronger environmental and communal, but not financial, motives promote people’s involvement in community environmental initiatives. The present paper examines whether appeals to such environmental or communal motives can promote involvement more than appeals to financial motives or no appeals. Three experimental studies revealed that environmental and communal appeals did not promote initiative involvement more than financial appeals or no appeals. Moreover, a combined environmental and communal appeal was not more effective than single appeals. Furthermore, in a field study examining 167 existing community energy initiatives, we found no relationship between the emphasis in flyers on financial, environmental, and communal benefits of initiative involvement and the proportion of community members involved in these initiatives. These findings suggest appeals may not be enough to promote initiative involvement. We discuss the theoretical and practical implications of these findings.