1.Previous studies examining the disease costs of sociality have largely focused on the link between group size and transmission. However, infectious disease spread is primarily driven by the organization of interactions between individuals.
2. We used statistical tools to review the organization of the interaction networks of 47 species, including mammals, birds, reptiles, fish and insects by categorizing each species into one of three social systems, relatively solitary, gregarious, and socially hierarchical. Additionally, using computational experiments of infection spread, we determined the disease costs of each social system.
3. We find that relatively solitary species have large variation in number of social partners, that socially hierarchical species are the least clustered in their interactions, and that social networks of gregarious species tend to be the most fragmented. However, these structural differences are primarily driven by weak connections, which suggests that different social systems have evolved unique strategies to organize weak ties.
4. Disease simulations show that social network organization can mitigate the disease costs of group living for socially hierarchical species when the spreading pathogens are highly transmissible. In contrast, highly transmissible pathogens cause frequent and prolonged epidemic outbreaks in gregarious species.
5. By evaluating the implications of network organization across social systems, our findings offer new perspective on the debate about the disease costs of group living. Additionally, this study demonstrates the potential of meta-analytic methods in social network analysis to test ecological and evolutionary hypotheses on cooperation, group living, communication, and resilience to extrinsic pressures.