The collective behavior approach and some versions of the political sociology perspective traced movements back to strains or deprivations in social order. Strain and deprivation models relegate Marx and Weber to supporting roles while bringing Emile Durkheim back for an encore. From the beginning, the Chicago School defined collective behavior in contrast with institutional behavior and routine social functioning. Neil Smelser proposes that collective behavior emerges through a similar value-added process of cumulative determinants. Smelser's theory attracted considerable criticism, partly for its Parsonian heritage and partly on its own terms. The concept of relative deprivation may also reconcile otherwise conflicting views of the origins of collective action in general and revolution in particular. Finally, the individualistic emphasis denies the political dimension of collective behavior by implying that it is nothing more than a 'convenient justification for what is at root a psychological phenomenon'.