Figure 2.

Fitness advantage of the signaler relative to the no-signaling equilibrium, as a function of the coefficient of relatedness k in the SPS game with signalers distributed uniformly on [0, 1]. The dotted curve is for complete information transfer at no cost, which we have included to illustrate the efficiency of the cost-free equilibria. The lowest curve is for complete information transfer, at the cost necessary to enforce the separating equilibrium. Intermediate curves are for partitions with 2, 3, 4, etc., cost-free signals.