  Axelrod's model describes the dissemination of a set of cultural traits in a
society constituted by individual agents. In a social context, nevertheless,
individual choices toward a specific attitude are also at the basis of the
formation of communities, groups and parties. The membership in a group changes
completely the behavior of single agents who start acting according to a social
identity. Groups act and interact among them as single entities, but still
conserve an internal dynamics. We show that, under certain conditions of social
dynamics, the introduction of group dynamics in a cultural dissemination
process avoids the flattening of the culture into a single entity and preserves
the multiplicity of cultural attitudes. We also considered diffusion processes
on this dynamical background, showing the conditions under which information as
well as innovation can spread through the population in a scenario where the
groups' choices determine the social structure.
