We explore evolutionary dynamics for repeated games with small, but positive complexity costs. To understand the dynamics, we extend a folk theorem result by Cooper (1996) to continuation probabilities, or discount rates, smaller than 1. While this result delineates which payoffs can be...

In evolutionary models of indirect reciprocity, reputation mechanisms can stabilize cooperation even in severe cooperation problems like the prisoner's dilemma. Under certain circumstances, conditionally cooperative strategies, which cooperate iff their partner has a good reputation, cannot be...

In repeated games there is in general a large set of equilibria. We also know that in the repeated prisoners dilemma there is a profusion of neutrally stable strategies, but no strategy that is evolutionarily stable. This paper investigates whether and how neutrally stable strategies can be...

In repeated games, reciprocity helps to sustain group cooperation. Using the Markovian strategy as a touchstone, we explore the evolution of cooperation in the infinitely repeated and noisy n-person Prisoner's Dilemma. With some modified game settings, we show that a class of cooperative...

There is continuing debate about what explains cooperation and self-sacrifice in nature and in particular in humans. This paper suggests a new way to think about this famous problem. I argue that, for an evolutionary biologist as well as a quantitative social scientist, the triangle of two...

We study the coevolution of cooperation, preferences and cooperative signals in an environment where individuals engage in a signaling-extended prisoner's dilemma. We identify a new type of evolutionary equilibrium - a transitional equilibrium - which is constituted and stabilized by the dynamic...

We propose a simple model for why we have more trust in people who cooperate without calculating the associated costs. Intuitively, by not looking at the payoffs, people indicate that they will not be swayed by high temptations to defect, which makes them more attractive as interaction partners....

We study the coevolution of cooperation, preferences, and cooperative signals in an environment where individuals engage in a signaling-extended prisoner's dilemma. We prove the existence of a cooperative equilibrium constituted by a (set of) limit cycle(s) and stabilized by the dynamic...