The consolidation of the human ultrasocial system depended on the development of the state as an institution supporting economic expansion and exploitation. Strong centralized states did not develop until thousands of years after the advent of settled communities. One key to the growth of state societies was grain agriculture. Grains could be stored, measured, and taxed, and they provided the economic surplus necessary to support large-scale cities and empires. States may have formed in periods of drought when the population was more easily managed. A critical function of the state was to control the organization of surplus production for the benefit of the ruling elites. Unlike social insects, the cohesion of the human superorganism is not based on genetics, but on institutions and cosmologies that support growth, exploitation, and hierarchy. Inequality is a uniquely human ultrasocial phenomenon. Humans have castes, ants do not.