The expression collective behavior was first used by Robert E. Park (1921), and employed later by Herbert Blumer (1939), Ralph Turner and Lewis Killian (1957), and Neil Smelser (1962) to refer to social processes and events which do not reflect existing social structure ( laws, conventions, and institutions), but which emerge in a "spontaneous" way. Use of the term has been expanded to include reference to cells, social animals like birds and fish, and insects including ants. Collective behavior takes many forms but generally violates societal norms (Miller 2000, Locher 2002). Collective behavior can be tremendously destructive, as with riots or mob violence, silly, as with fads, or anywhere in between. Collective behavior is always driven by group dynamics, encouraging people to engage in acts they might consider unthinkable under typical social circumstances (Locher 2002).