What games support the evolution of an ingroup bias?

Both analyses and simulations show that an ingroup bias evolves in (anti-)co-ordination games. The simulations further show that the strategy becomes particularly prevalent in stag hunts. The picture depicts, to the left, the games derived from the game matrix, in the middle, for different values of x and y. The panel to the right shows the simulated proportional prevalence of an ingroup bias for the different games when there are 10 groups in the population.