The Evolution of Assortment with Multiple Simultaneous Games

Current theories of social evolution predict the direction of selection for a given level of assortment. What remains unclear is how to determine the direction of selection on assortment itself if this were subject to evolutionary change. Here we define and analyse a simple model that allows us to investigate the evolution of assortment. We find that there is only a positive selection gradient for increased assortment if the population is polymorphic in the cooperative trait. We further show that if the individuals in question engage in multiple cooperative dilemmas simultaneously then there may be a continued selection on increased assortment which is ultimately sufficient to resolve severe dilemmas such as the prisoner's dilemma.