Function of hierarchy on Cooperation in large-scale human societies

Many studies suggest that cooperation in human societies has been achieved via peer interactions such as reward and punishment. As the group size is larger, however, it is difficult to maintain cooperation only by peer interactions. Instead, a centralized punishment system such as police governs large-scale societies and cooperation is maintained. In this paper, first, I explain why peer interactions have limitations to achieve large-scale cooperation and why centralized punishment system, which often includes social hierarchy, has superiority. Second, I discuss how social hierarchy can be formed and maintained. Considerable evidence indicates that hierarchy in humans is principally based both on dominance (coercive capacity based on strength and threat) and prestige (persuasive capacity based on skills, abilities, and knowledge). Some researchers argue that non-human animals also form hierarchy based on dominance, but only humans form stratification based on prestige. After introducing their argument, I would like to discuss how humans (and other animals) form hierarchy and achieve cooperation.