Cooperation among animals in the iterated prisoner's dilemma: a computational model of discounting and reciprocity

S. E. LEW, D. JERCOG, B. S. ZANUTTO

Washington, DC

Congreso; Society for Neuroscience, 2008. Program No. 89.19/SS36; 2008

Society for Neuroscience

In different biological environments, adaptive systems had evolved with the characteristic of guarantee their own replication success. As a consequence of this consideration, one of the most important apparent paradoxes of evolutionary theory is cooperation among individuals. A central paradigm to study cooperation is the Iterated Prisoner's Dilemma (IPD).As well, at the situation of choose between a small-immediate and a large-delayed appetitive reinforce, animals shows a strong tendency to choose the first option. The phenomenon, known as temporal discounting, has been shown in different species some of them phylogenetically very different. This effect brings important consequences on the Iterated Prisoner's Dilemma (IPD), the central paradigm in studies of cooperation. Although to cooperate - from a theoretical point of view - is the best option under reciprocity conditions, non-human animals show a strong tendency to defection. The reasons are still unclear, but one possible explanation is that rewards from cooperation may be delayed, and the effect of that delay causes a reduction on the value of the future benefit of cooperative action.On the other hand, it has been showed that captive blue jays are capable of sustain cooperation on the IPD framework, and the key to do that is a mechanism of food accumulation (making the food visible but not accessible) along a defined number of trials.In this work we propose a computational model that simulates the effects of discounting and reciprocity in the Iterated Prisoner's Dilemma.