  In many indigenous societies, people are categorised into several cultural
groups, or clans, within which they believe to share ancestors. Clan
attributions provide certain rules for marriage and descent. Such rules between
clans constitute kinship structures. Anthropologists have revealed several
kinship structures. Here, we propose an agent-based model of indigenous
societies to reveal the evolution of kinship structures. In the model, several
societies compete. Societies themselves comprise multiple families with
parameters for cultural traits and mate preferences. These values determine
with whom each family cooperates and competes and are transmitted to a new
generation with mutation. The growth rate of each family is determined by the
number of cooperators and competitors. Through this multi-level evolution,
family traits and preferences diverge to form clusters that can be regarded as
clans. Subsequently, kinship structures emerge, including dual organisation and
generalised or restricted exchange, as well as patrilineal, matrilineal, and
double descent systems. These structures emerge depending on the necessity of
cooperation and the strength of mating competition. Their dependence is also
estimated analytically. Finally, statistical analysis using the Standard
Cross-Cultural Sample, a global ethnographic database, empirically verified
theoretical results. Such collaboration between theoretical and empirical
approaches will unveil universal features in anthropology.

Physics and Society;Adaptation and Self-Organizing Systems