Game theory is your savior. You’re right that complexity is the root, both of the challenge to understanding these interactions and of the emergent qualities that provide so much benefit. Culture of any complexity emerges from rules.

James Buchanan (econ. Nobel 1986) on game theory: “The core insight, it seems to me, is that people choose among strategies and out of that emerges outcomes that are not part of anyone’s choice set. It is a different way of looking at economics and it gets us to focus on fundamental issues of economic coordination that have been neglected. This, I think, is the direction that formal economic theory ought to take.”

Economic coordination taking place at the animal and plant level also benefits from exactly this game-theoretical analysis. The late John Maynard Smith furthered this analysis nicely with regard to Evolutionarily Stable Strategies (explicated nicely by Dawkins in, e.g., The Extended Phenotype) among social insects. First World economic systems and cultures are not qualitatively more complex than ecosystems.

Come to think of it, semantics emerges from the grammatical (syntax, morphology, etc.), too, so long as the relatively few, simple rules allow expressiveness. Any human language, first-order logic with contexts, and economic systems all are expressive enough to handle anything. The order of First World cultures can emerge from “grammatical” rules as easily as any Third World culture.