collective behavior

Meaning: Collective behavior is relatively spontaneous, loosely organized action by a large number of people responding to a shared situation, usually without established institutions or clear leaders. Examples are crowds, mobs, riots, panics, fads, crazes and rumors. Three theories explain it. Contagion theory says emotions and ideas spread through a crowd, and anonymity lowers restraint. Convergence theory says like-minded people gather, so the behavior reflects traits they already had. Emergent-norm theory says new norms form in an ambiguous situation and members conform to them.

On the MCAT: A passage describes a riot, a panic or a viral trend and asks which theory fits. Individuals swept up and losing self-restraint suggests contagion. People with similar prior attitudes assembling suggests convergence. Rules taking shape during the event suggests emergent norms. Related ideas such as deindividuation and conformity may also appear in the answer choices.

Common confusion: Collective behavior is not the same as the behavior of a formal organization, and it is not always violent, since fads and rumors count. Convergence places the cause in the individuals who come together, while contagion places it in the crowd's influence on individuals.