Print PageUnderstanding the evolution of complex social behaviors such as cooperation is one of the most important challenges in evolutionary biology and the social sciences. An old and unresolved controversy regarding social behaviors is whether and when natural selection can lead to behaviors that maximize fitness at the level of a social group, but are costly at the individual level. Except for the special case of groups composed of clones, it is not known whether and when adaptations at the group level occur, especially when the behaviors in question are flexible. To address this question, we develop a general framework that integrates behavioral plasticity in social interactions with the action of natural selection in structured populations where individuals can be related due to common ancestry.
Results/Conclusions
We find that group adaptations are a possible outcome of evolution, even without clonal groups, if individuals exhibit appropriate behavioral responses to each other's actions that align individual interests with the group interest. Importantly, the evolution of these behavioral responses is predicated on proximate behavioral mechanisms such as prosocial preferences. Our model demonstrates the importance of the interplay between behavioral responses and relatedness in determining the course of social evolution. This work also highlights the crucial role of proximate mechanisms, such as prosocial preferences, that generate the behavioral flexibility. Studying the evolution of such mechanisms in structured populations therefore presents a fruitful avenue for both evolutionary biology and the social sciences.
