Allelomimesis as a generic clustering mechanism for interacting agents

We show that allelomimesis is a generic mechanism that could explain why the cluster-size distribution D(s) of diverse social aggregates such as animal groups and socio-economic entities all fit into a power-law distribution: D(s)∝s−τ, where τ is the critical exponent. Roughly, allelomimesis is the tendency of an agent to imitate the actions of its neighbors. A cellular automata model of allelomimesis yields a population-age distribution which is consistent with the assumption of evolutionary biologists that isolation does not enhance the life expectancies of agents. Dependence of τ with degree of allelomimesis is highly nonlinear. The different experimental τ values yielded by the size distributions of real systems such as fish schools, African buffalo herds, US financial firms, and towns around London and Berlin, might be understood as arising from the varying degrees of allelomimesis by system constituents.