This article presents the possibilities and advantages of integrating social psychology and political science in the study of intergroup relations in diverse societies in Western Europe. Social psychology provides interesting insights in understanding the emotional and cognitive consequences of increased diversity. However, this literature tends to overlook the role of institutional discourses and correlated practices in stimulating or constraining positive intergroup relations. In order to fill these lacunae, the article suggests the integration of social psychology and a ‘political opportunity structure’ approach. This article maintains that the political opportunity structures operating in a context are not only important for understanding actors' mobilisation, as usually maintained in the literature, but also for studying the extent to which change at the micro-level of social interaction can be stimulated or constrained. We illustrate the arguments of the article with an analysis of the narrative constructions and the correlated practices of integration as adopted by the city councils of Malmö and Bologna. Copyright © 2011 John Wiley & Sons, Ltd.