Layered social influence promotes multiculturality

Why are social systems inherently multicultural? To answer such question, Axelrod proposed a model of culture dissemination based on the two simple mechanism of homophily (similar individuals are more likely to interact) and social influence (interactions increase the number of common traits of two individuals). The model predicts the transition from a single dominant culture to a regime of global polarization where different cultures can coexist: when the cultural profile of an individual is described by a set of features, and each cultural feature takes many different traits, cultural diversity can persist in spite of the local tendency towards convergence. Moreover, the higher the average path length of the social networks, the lower the facility to reach globalisation. However, all multicultural regime have been shown to be unstable under cultural drift, i.e. spontaneous mutation of traits in the population. Individuals tend to diversify the recipients of their interactions according to their subject. In the classical model, however, imitation occurs at all levels regardless of the nature of each connection. In such work we introduce layered social influence by keeping into account the nature of different relationships and assuming that each interaction in a certain social circle can affect only specific cultural features of an individual. We show that the introduction of layered social influence has a dramatic impact on the stability of multicultural regimes, thus potentially explaining the persistence of multiculturality in real-world societies.