The eternal struggle between cooperative and selfish social strategies takes place on the playing field of theoretical models in addition to the real world. The prisoner's dilemma is a favorite model for exploring advantages and pitfalls of cooperation. Last year, an article published in the Proceedings of the National Academy of Sciences by William H. Press and Freeman J. Dyson, titled "Iterated Prisoner's Dilemma contains strategies that dominate any evolutionary opponent", caused a stir by identifying an extortionist strategy that can outcompete any more cooperative strategy. More recently, an article published in PNAS by Alexander Stewart and Joshua Plotkin titled "From extortion to to generosity, evolution in the prisoner's dilemma" shows that generous strategies win the Darwinian contest after all. I talk with Stewart and Plotkin about their new result against the background of Press and Dyson's paper, the prisoner's dilemma model, and the somewhat rarified world of theoretical biology. Learn how classical game theory differs from evolutionary game theory, why mathematicians employ seemingly unrealistic assumptions such as games that are infinite in length, and how Press and Dyson's result remains beautiful and laid the groundwork for Stewart and Plotkin's contribution.



This discussion of theoretical issues provide an intriguing complement to my interview with Adam Grant on giving and taking strategies in real-world business environments.