In games like the Hawk-Dove, Prisoner's Dilemma and Stag Hunt, cultural similarity (as measured by cultural Fst) promotes selection for group-beneficial outcomes. This theoretical finding is consistent with several recent empirical studies, showing that CFst predicts willingness to cooperate. 2/

But that's not the only kind of social dilemma - consider the simple game of having to drive on the left or right side of the road. In simple coordination games, we find cultural *diversity* (i.e. low CFst) rather than similarity promotes the evolution of a social optimum. 3/