In Growing Artificial Societies, Axtell and Epstein learn from their study of the Sugarscape agent-based modeling environment to conceive of fitness as an emergent property because instead of being a characteristic of an individual per se it involves “sustainable co-evolution with one’s environment” .
Imagine a world power that invades a weak developing state on the assumption that fitness on the battlefield is a function of the individual characteristics of the soldiers on each side (e.g., weapons, training) only to discover to its chagrin that its very presence as an invader in the enemy state provokes co-evolution of the occupied population and their environment. The environment may evolve from rigid but independent dictatorship where everyone keeps his head down and in return has a job (e.g., in the army or bureaucracy) to an environment in which foreigners get all the jobs, the people are unemployed (e.g., the army is disbanded and all the local soldiers go home to hang around with their buddies on street corners feeling humiliated). The population, in turn, may evolve from passive and risk-averse to radical and risk-seeking in an effort to regain fitness so it can survive. Meanwhile, the invader continues to trust its initial (quite correct, at the time) assumptions about relative fitness without considering that it has provoked rapid evolution of the environment, which in turn is provoking rapid evolution of the behavior of members of the conquered society. Suddenly, the invader finds itself unfit to win the war.
Suffice it to say that Growing Artificial Societies was written well before the Bush-Cheney invasion of Iraq and that government scientists were well aware of this path-breaking study. The White House, of course, was oblivious. Indeed, this way of thinking about the world appears to remain utterly foreign to Washington decision-makers’ way of thinking.