Collective behavior

Collective behavior is group action that emerges outside or beyond established social structures and routines, often through interaction among participants.

Emergent behavior: Large-scale patterns that arise from interactions among simpler parts without central direction. Collective action can produce group-level patterns no participant planned.
Social structure: The patterned relationships, roles, and institutions that organize social life. Collective behavior departs from or exceeds established patterns of social organization.
Panic of 1907: A financial crisis in the United States marked by bank runs and a severe contraction in credit. Bank runs show how public responses can intensify rapidly through mutual observation.
Social movement: A sustained, organized effort by people seeking social or political change. Movements rely on continuity and organization, unlike many short-lived collective episodes.
Social contagion: The spread of behaviors, emotions, or ideas through social contact and observation. Actions and feelings can spread through a gathering as people observe one another.
Social norm: A shared expectation about appropriate conduct within a group or society. Unusual gatherings may lack settled norms or generate new ones.
Tulip mania: A speculative episode in the Dutch Republic during the 1630s involving sharply rising and falling tulip prices. It illustrates collective expectations and imitation in a market setting.
Crowd psychology: The study of how people think and act in crowds, including theories of crowd influence. Its explanations of crowd conduct have shaped accounts of collective behavior.
Convergence theory: A theory that people with similar predispositions converge to produce collective action. It explains how shared grievances or beliefs can bring a crowd toward common action.
Group dynamics: The patterns of interaction and influence that develop among members of a group. Collective behavior is one form of interaction among people acting as a group.

Linked from 24 pages