The emergence of collective locomotion

Collective locomotion is a ubiquitous feature of the natural world, found in living systems great and small – from migrating skin cells to flocks of starlings. In humans, collective locomotion is one form of interpersonal coordination, a term that encompasses many of the social and cultural activities that define our species. Whereas studies of interpersonal coordination often focus on the synchronization of rhythmic movement, the domain also includes non-rhythmic coordination, which calls for other tools of analysis. In this introductory chapter our goal is to examine collective locomotion in bird flocks, fish schools and human crowds as a case study for understanding this broader range of interpersonal coordination. Despite vast differences across species – including morphology, neurophysiology, perception and cognition – these seemingly diverse phenomena obey common principles of self-organization and may share similar local mechanisms.