ABSTRACT
When dealing with social situations it is usually believed that one of the main difficulties comes from the rich variety of individual characteristics involved (Burnstein & Vinokur, 1973; Dion, Baron, & Miller, 1970). Along these lines the complexity of a group is expected to be an increasing function of its size. However crowds, which contain large numbers of persons, behave in some aspects like one collective individual making some behavior even simpler than in the case of one individual (Turner, 1987). This paradox suggests that within a group the individual complexity should decrease in parallel to the appearance of a new individual reality, which is the “collective dimension.” In this context it is of particular importance to discriminate between, on the one hand, properties associated with purely individual characteristics, and on the other, those properties that result from the existence of a collectivity or social system (Galam & Moscovici, 1991, 1994, 1995).
