Evolving group strategies for IPD

The Iterated Prisoners Dilemma (IPD) is often used to model cooperation between self-interested agents. In an earlier study, we introduced a framework using IPD to study the effects of species-level competition on the evolution of cooperative behaviour. In this paper, we extend the previous work, using co-evolutionary simulations of interactions between species of IPD-playing agents to investigate how group strategies may evolve. We find that the ability to cooperate more with agents of the same species greatly increases the ferocity of competition between species.