Institutions are sometimes represented as a state-imposed set of rules of the game regulating social interactions in a population. But the cooperative and egalitarian practices and other enduring social structures observed among foragers in the ethnographic record almost certainly governed social interactions since the appearance of biologically modern humans hundreds of thousands of years ago. The subsequent emergence of private property as a fundamental institution predates states by many millennia. In the absence of state rule, institutions such as sharing the necessities of life beyond the family and respecting the property rights of others resemble linguistic conventions, conformity with which is a mutual best response conditional on most others conforming. Recent archaeological evidence along with models of sharing and private property as conventions suggest that what the first states accomplished was not to have put an end to Hobbes’ chaotic state of nature and its “warre of every man against every man,” but instead, more in line with Engels than Hobbes, to have expanded the scope of coordinated social interactions and to have inaugurated unprecedented and enduring levels of inequality of wealth.