The lives of social animals, none more so than humans, are shaped by cooperative interactions. Sharing, exchange, and synergy are the name of the game. Understanding the origins of cooperative behavior with any clarity often requires formalization of theories in the way of mathematical and computational models. These models by necessity ignore many details of an organism’s ecology, life history, and behavioral repertoire. Nevertheless, models provide crucial scaffolds for theory development, partly by explicitly declaring all of their assumptions and thereby making their limitations clear. That said, we can always stand to improve. I will discuss mathematical and computational models of the evolution of cooperative behavior, and how our assumptions about individual behavior, life history, and environmental structure influence our conclusions concerning how social populations evolve. In particular, I will focus on the advantages of complicated models in which life history and population structure are included, even when those factors are not the explicit targets of investigation.