Collective behaviour, social movements and mass psychology

This chapter focuses on the dynamics of collective behaviour, social movements and mass psychology. The topic is receiving renewed attention as the potential drivers of, for example, climate change denial, political populism, and inequality. These topics are central to the study of social complexity because they focus on the intersection of social psychology and the social systems in which we live. In this chapter, we situate these topics historically within political psychology and social psychology. We explore what Luhmann and other systems theorists have written on the topic; and how and why their ideas (along with political psychology and related areas) remain on the margins of the complexity sciences - undeservedly so. We investigate the consequences of this marginalization with the example of opinion dynamics; ending with the work of Castellani to illustrate one possible way to get by these barriers to advance this topic.