Erol Akcay: University of Tennessee National Institute for Mathematical and Biological Synthesis (NIMBioS)

There is extensive work on the evolutionary causes of social behaviors, but integration of this theory with the proximate mechanisms of behavior has lagged behind. Here, I will present a new modeling approach to achieve such integration. The model rests on goal-oriented motivations, or preferences, as the proximate determinants of behavior and describes the dynamics of a social interaction at the behavioral time scale. During these behavioral dynamics, individuals can respond to each other’s actions, and these responses ultimately drive the evolution of the proximate motivations.

We first apply this framework to the question of other-regarding motivations. We find that other-regarding motivations can evolve even when there is complete conflict of interests between the individuals, and in the absence of group- or kin-selection. We then turn our attention to the evolution of conformist motivations, and explore conditions that facilitate their evolution. Finally, we generalize our framework to include the joint effects of behavioral responses trough proximate mechanisms and selection in structured populations. The resulting model illuminates the interplay between behavioral responses and relatedness in the evolution of social behaviors. In particular, we find that behavioral responses can facilitate the evolution of group-optimal behaviors, and result in transitions between levels of selection.