Along with the origins of agriculture, the appearance of complex societies – often called ‘chiefdoms’ and ‘states’ – is one of the most widely discussed social processes in the archaeological literature. Explanations for the beginnings of complex societies commonly involve ideas of progressive social evolution.
An alternative approach for understanding the evolution of social complexity is based on concepts derived from the study of complex systems. As we illustrate below, complex systems give us new conceptual tools for studying the social processes that drove the evolution of small agricultural communities into political states. Complex systems are composed of many interacting components organized into nested groups that can be represented as organizational hierarchies or hierarchically structured networks; the more complex the system, the deeper the nesting of the groups of components. In human terms, such nested groups could be nuclear families within forager bands, and bands within regional metapopulations. They also could be households within clans within chiefdoms, or individuals within craft guilds, within a city within a state.