Studying games to understand the evolution of cooperation
All it took to rewrite the rules of understanding the evolution of cooperation was a series of chance encounters among Martin Nowak, Krishnendu Chatterjee, and Christian Hilbe. During his first visit to Harvard in 2008, Chatterjee, a computer-science professor at IST Austria, mentioned stochastic games — games that can change based on players’ actions — and the idea sent Nowak down a years-long path to merge the concept with evolutionary dynamics. “People who study evolution of cooperation do not use stochastic games,” said Nowak, who developed the new framework in collaboration with Chatterjee, Hilbe, a postdoctoral fellow in Chatterjee’s group at IST, and Stepan Simsa of Charles University in Prague. “Instead, in a sequence of repeated encounters, it is assumed that the same game with the same payoff matrix is played again and again. In a stochastic game, the game itself can change probabilistically depending on the players’ actions.” That new approach, described...