  Social groups with widely different music tastes, political convictions, and
religious beliefs emerge and disappear on scales from extreme subcultures to
mainstream mass-cultures. Both the underlying social structure and the
formation of opinions are dynamic and changes in one affect the other. Several
positive feedback mechanisms have been proposed to drive the diversity in
social and economic systems, but little effort has been devoted to pinpoint the
interplay between a dynamically changing social network and the spread and
gathering of information on the network. Here we analyze this phenomenon in
terms of a social network-model that explicitly simulates the feedback between
information assembly and emergence of social structures: changing beliefs are
coupled to changing relationships because agents self-organize a dynamic
network to facilitate their hunter-gatherer behavior in information space. Our
analysis demonstrates that tribal organizations and modular social networks can
emerge as a result of contact-seeking agents that reinforce their beliefs among
like-minded. We also find that prestigious persons can streamline the social
network into hierarchical structures around themselves.
