Empires rise and fall, he [Peter Turchin] suggests, because of "competition and conflict between groups, some of which dominate others". On the world stage, ethnic groups - identified by race, language and other markers - compete with one another for resources, land and so on. Plausibly enough, those able to muster and sustain a higher level of internal cooperation should tend to prevail, doing a better job of providing a collective defence or in coordinating attacks against others.
In this sense,
Turchin sees history as an evolutionary competition between more or less cooperative groups, and this raises two natural questions. First, how do new highly cooperative groups emerge, and so become candidates for expansion and the founding of new empires? Second, what happens to these cooperative groups that eventually undermines their success?
A fundamental idea of biology is that new adaptive traits emerge most readily where evolutionary pressure selects for them. Birds evolve longer beaks only under conditions in which longer beaks make a real difference to a bird's fitness. Following this idea, Turchin argues that particular geographical zones should act as incubators for highly cooperative groups, because they impose conditions under which cooperation really matters.
In particular, he suggests, peoples that live at the boundaries of existing empires face serious threats as those empires attempt to expand. On the other hand, such peoples may also have opportunities for beneficial trade with the empire. "In the pressure cooker" of such a zone, Turchin suggests, "poorly integrated groups crumble or disappear whereas groups based on strong cooperation thrive and expand".
"It is the very success of an empire that sets up the conditions for its demise"
So,
the idea goes, the frontiers of existing empires offer fertile territory for seeding highly cooperative groups that might then grow into new empires. Turchin argues that a number of historical examples fit this pattern. Russia rose up out of a three-century battle to survive in the face of murderous raids by Tatar bands from the steppe to the south. America grew strong and cohesive during a similarly murderous three-century battle to survive and expand against indigenous people.
Curiously, this part of Turchin's argument finds support in modern experimental economics and anthropology. Experiments over the past decade or so have established that most individuals aren't the greedy, rational machines of neo-classical economics, but are often willing to cooperate with others even when they clearly have nothing to gain by doing so. Some of the most convincing efforts to explain such "irrational" tendencies point to a process of cultural group selection that looks surprisingly like Turchin's historical dynamics - competition between groups of greater or lesser cooperative skills, with the more cooperative tending to win out.
Mark Buchanan's latest book is Small World, Weidenfeld & Nicolson, 2003 From issue 2519 of New Scientist magazine, 01 October 2005, page 44
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