Multilevel Organisation of Animal Sociality

Multilevel societies (MLSs), stable nuclear social units within a larger collective encompassing multiple nested social levels, occur in several mammalian line-ages. Their architectural complexity and size impose specific demands on their members requiring adaptive solutions in multiple domains. The functional signif-icance of MLSs lies in their members being equipped to reap the benefits of mul-tiple group sizes. Here, we propose a unifying terminology and operational definition of MLS. To identify new avenues for integrative research, we synthe-sise current literature on the selective pressures underlying the evolution of MLSs and their implications for cognition, intersexual conflict, and sexual selec-tion. Mapping the drivers and consequences of MLS provides a reference point for the social evolution of many taxa, including our own species.