Dominance Orders in Animal Societies: The Self-Organization Hypothesis Revisited

In previous papers (Theraulaz et al. 1995, Bonabeau et al. 1996) we suggested, following Hogeweg and Hesper (1983, 1985), that the formation of dominance orders in animal societies could result from a self-organizing process involving a double reinforcement mechanism: winners reinforce their probability of winning and losers reinforce their probability of losing. This assumption, and subsequent models, were based on empirical data on primitively eusocial wasps (Polistes dominulus). By reanalyzing some of the experimental data that was previously thought to be irrelevant, we show that it is possible to distinguish this assumption from a competing assumption based on preexisting differences among individuals. We propose experiments to help discriminate between the two models---the self-organization model and the correlation model. We urge other researchers to be cautious when interpreting their dominance data with the "self-organization mindset": in particular, "winner and loser effects," which are often considered to give support to the self-organization assumption, are equally consistent with the correlation model. To appear in Bull. Math. Biol., June 1999.