Contingent dispersal and the formation of cooperative groups
Cooperation can be observed at all levels of biological and social organization. This is puzzling from a theoretical perspective, since simple models predict that, while cooperation would be most advantageous for a group as a whole, non-cooperation is always the most successful strategy for each individual comprising such a group. In the real world, however, interaction groups are not fixed. Individuals can typically choose which groups to interact with, and over time often derive their long-term benefits from participating in many groups. Consequently, accounting for the movement of individuals between groups must be of pivotal importance for understanding the emergence of cooperation in realistic scenarios. Here, I investigate how cooperation is maintained in large populations in which individuals freely move between interaction groups, making decisions to stay or leave based on certain cues, such as group size or cooperation level. In this context, I will analyze the evolution of contingent dispersal, by which individuals respond to such cues in their local environment. The resulting dispersal strategies are likely to underpin the formation and stability of cooperative groups. This analysis will contribute to the theory of the emergence and dynamics of cooperation in larger systems, such as ecological communities or large-scale social organizations, and may lead to new policy recommendations concerning the governance of public goods.