Evolutionary stability of honest signaling in finite populations

We study honest signaling in the Philip Sidney game. Until now, researchers concentrated on verifying under what circumstances honest signaling is an evolutionarily stable strategy (ESS). Whereas the concept of ESS assumes infinite populations, we analyze here, for the first time, the more realistic scenario where populations are finite-which allows us to study the effect of varying the population size with respect to the viability of honest signaling. We show that honest signaling is much less frequent than previously observed within the infinite population setting. We observe that population size has a similar effect as selection pressure, namely, the larger the population the more important the difference in fitness between the strategies. Our experiments reveal, furthermore, that evolutionary stability is not very predictive for the viability of honest signaling. Most surprisingly, we found cases where honest signaling is the most prevalent strategy but not evolutionarily stable.