Robert Axelrod — Six Advances in Cooperation Theory (2000)
Written approximately twenty years after Axelrod’s landmark iterated Prisoner’s Dilemma tournaments (published in The Evolution of Cooperation, 1984), this paper synthesizes what has been learned: (1) robustness of tit-for-tat-style strategies, (2) the role of reputation and network structure, (3) the evolution of norms for punishing defectors, (4) the formation of ethnic and group markers as coordination devices, (5) the role of spatial proximity, and (6) the evolution of the internal structure of actors (i.e., how agents themselves develop over time in repeated interactions).
The original Evolution of Cooperation established that cooperation can emerge among self-interested actors in repeated interactions without external enforcement — a result with significant implications for political philosophy, economics, and evolutionary biology. The 2000 paper updates the picture with two decades of additional modeling and empirical work.
For OM: the cooperation theory tradition provides the game-theoretic baseline against which OM’s Moloch critique is developed. OM’s point is not that cooperation theory is wrong, but that it cannot address problems with ontological roots — the Prisoner’s Dilemma cannot be solved if the game board itself is what needs to change.