Centrifugal ForcesI can't think of a time when I wasn't interested in this topic. Most people -- wrongly, I think -- consider highly consolidated and homogenous societies and cultures superior to fragmented ones. Cuz after all, that's what great empires are; power comes from centralization. Or, as per Brooks Adams's dictum: "all civilization is centralization; all centralization is economy."
But just as biological sameness invites disaster from pathogens or environmental changes, so too does social, political and cultural homogeny (or intense consolidation). Michael Crichton has Ian Malcolm say, in one of the Jurassic Park novels, words to the effect that the invention of the internet means the end of human evolution. Why? Because biological and cultural diversity was maintained, and technological and cultural innovation furthered, through semi-isolated bands.
But semi-isolated bands do not enslave the massive amounts of people or flex the economic muscle which together are needed to build great monuments or organize massive campaigns. So they're devalued by history.
The following is part of an essay on Cahokian identity by Robert L. Hall and included in the book Cahokia and the Hinterlands: Middle Mississippian Cultures of the Midwest (pp 26):
I attribute the decline of Cahokia, in sum, to the operation of what I call the Shmoo Effect, a frontier effect bringing about the devolution or breaking down of social organization in the face of abundance and diminished need for interdependence... The Shmoo Effect operates in reverse of the principle of circumscription that Robert L. Carneiro (1970) offers in explanation of the origin of the state. An example of a frontier effect selected from the literature of anthropology would be that provided by Elman R. Service for the Maori of New Zealand:The Maori originally came from the central region of Polynesia where chiefdoms were highly developed, but when they colonized the huge, open environment of New Zealand, they subdivided and scattered. In so doing they reverted to a less centralized and less organized form of society, eventually coming to resemble tribal society more than their original chiefdom form...
[T]he Polynesians who settled New Zealand found a wide-open environment to expand into, so that frontier-like pioneering was possible and a leader of low heredity position could nevertheless by charismatic force gain a following and raise his status by achievement in carving out a new domain. Thus the Maori of New Zealand have been described as more "democratic" than most of the other Polynesian chiefdoms (1962:147, 161).
A frontier, of course, can be opened by migration and discovery, sometimes assisted by force of arms, or by technological innovation that creates a new resource area or improves an old one. If this frontier model is correct, it makes the process of Mississippian decline in the Cahokia area essentially isomorphic with the process of Hopewellian decline in Illinois a thousand years earlier, as that decline has been interpreted by several investigators...