MARTIN NOWAK is a Mathematical Biologist, Game Theorist; Professor of Biology and Mathematics, Director, Center for Evolutionary Dynamics, Harvard University; Coauthor (with Roger Highfield), SuperCooperators: Altruism, Evolution, and Why We Need Each Other to Succeed.
There is one thing that I have learned in my studies of cooperation over the last 20 years: there is no equilibrium. There is never a stable equilibrium. Cooperation is always being destroyed and has to be rebuilt. How much time you spend on average in a cooperative state depends on how quickly you can rebuild it.