Evolution of Autonomous Hierarchy Formation and Maintenance

Hierarchy among social animals is ubiquitous, and affects the social structures of gregarious species not only by interaction among species within the population, but also through other social forces such as mating, nesting location, amount and the quality of food they receive, or reproductive success. Since T. Schjelderup-Ebbe developed the structural definition of dominance and hierarchy in 1922 (see, e.g., Drews (1993)), different aspects of this social behavior have been addressed. However, exactly how hierarchies can emerge and be maintained among social species is still a conundrum. To investigate this issue, here we analyze a population of autonomous agents (”animates”) through the course of evolution. The results of our experiments demonstrate the importance of memory and brain plasticity for the emergence of hierarchy and dominance behavior.