Social representations and individual representations:what is the difference? And why are individual representations similar?

This paper clarifies a long-standing ambiguity in the notion of social repre-sentations; it provides a clear operational definition of the relation between social representa-tion and individual representation. This definition, grounded in the theory of sets, supports most current empirical investigation methods of social representations. In short, a social rep-resentation of an object in a population is the mathematical set of individual representations the individuals of that population have for this object. The components of the representation are the components used to describe this set, in intension in the mathematical sense of the term (in contrast with a definition in extension). Statistical techniques, as well as content analysis techniques, can construct such components by comparison of individual representa-tions to extract commonalities, and that is what classic investigations on social representations indeed do. We then answer the question: how come that, in a given culture, individuals hold individual representations that are so similar to one another?