Robert Axelrod

Evolution of Cooperation; tit-for-tat.

Robert Axelrod is Professor of Political Science and Public Policy at the University of Michigan. His 1984 book The Evolution of Cooperation, based on computer tournaments of the iterated prisoner's dilemma, showed that tit-for-tat — cooperate first, then mirror your opponent — consistently outperforms exploitative strategies. His work reshaped thinking in economics, biology, and international relations.