Reanalyzing 12 experiments on the repeated prisoner's dilemma (PD), we robustly observe three distinct subject types: defectors, cautious cooperators and strong cooperators. The strategies used by these types are surprisingly stable across experiments and uncorrelated with treatment parameters,...

In economic and social relationships, such as employment and marriages, participants often have the option to separate from their partner. This study experimentally investigates how the option to separate with or without a cost affects cooperation in indefinitely repeated prisoner’s dilemma...