Cooperators should be evolutionary extinct because cheaters always benefit more than cooperators. However cooperation is all around us and without it human society, could not exist. One of the mechanisms which could explain how cooperation emerged and persisted is direct reciprocity, under which the individuals cooperate with each other to ensure future cooperation. A number of strategies emerge in theory which would be the most beneficial to the players in this setting and also lead to high cooperation. However it is still uncertain if these are the strategies people actually use.
Here, I will conduct a series of Iterated Prisoner’s Dilemma experiments where large numbers of players play long games through a computer interface. Typically experiments which search for strategies have very small number of rounds and the resulting level of cooperation is not very high. However, in longer experiments after the initial drop, the level of cooperation is rising to a very high level. The question is what are the strategies that people use when cooperation is established and what kind of behaviour drives this change. Afterwards, I will perform experiments which will test how outside contexts (like the information the players receive, etc.) influence the strategies. Finally, I will pay special attention to the possibility of negotiation during the game. We will test if the inferred strategies explain the observed behaviours using agent based simulations and evolutionary models.