ABSTRACT
"Social differentiation of functions", "social division of labour", plurality of "social realm", " register of action", "social circles", "interaction scenes", "worlds", "fields", "under-spheres" or "systems" – all these sociological words are evidence of the interest of scholars in the realities of differentiation. This chapter explains the effects of social differentiation of activities on mental and behavioural structuring of individuals, trying to draw some consequences from a point of view of a sociology of social "dispositionalism". The internal plurality of individual actors clearly appears in lots of sociologists' thoughts who explicitly linked it with the forms of social life in which the actors in question are required to be part of. The multiple socialisation of individuals in differentiated societies is what is first giving credit to all the inter-individual variation in their social behaviour. Intra-individual and inter-individual variations are microscopic realities, which refer to the fundamental properties of a macroscopic reality characterised by the complex and differentiated structure of our societies.
