We study direct group reciprocity considering the complete set of reactive strategies, where individuals behave conditionally on what they observed in the previous round. We study both analytically and by computer simulations the evolutionary dynamics encompassing this extensive strategy space, witnessing the emergence of a surprisingly simple strategy that we call All-Or-None (AoN). AoN consists in cooperating only after a round of unanimous group behavior (cooperation or defection), and proves robust in the presence of errors, thus fostering cooperation in a wide range of group sizes. The principles encapsulated in this strategy share a level of complexity reminiscent of that found already in 2-person games under direct and indirect reciprocity.
Recommended citation: Flávio L Pinheiro, Vítor V Vasconcelos, Francisco C Santos, and Jorge M Pacheco. “Evolution of All-or-None strategies in repeated public goods dilemmas” PLoS computational biology (2014) 3 11 e1003945