The group engagement model: procedural justice, social identity, and cooperative behavior.

The group engagement model expands the insights of the group-value model of procedural justice and the relational model of authority into an explanation for why procedural justice shapes cooperation in groups, organizations, and societies. It hypothesizes that procedures are important because they shape people's social identity within groups, and social identity in turn influences attitudes, values, and behaviors. The model further hypothesizes that resource judgments exercise their influence indirectly by shaping social identity. This social identity mediation hypothesis explains why people focus on procedural justice, and in particular on procedural elements related to the quality of their interpersonal treatment, because those elements carry the most social identity-relevant information. In this article, we review several key insights of the group engagement model, relate these insights to important trends in psychological research on justice, and discuss implications of the model for the future of procedural justice research.