Arenas, AlexCamacho, JuanCuesta, José A.Requejo, Rubén J.2015-02-202015-02-202011-06-21Journal of Theoretical Biology, 279(1), Jun. 2011, pp. 113–1190022-5193https://hdl.handle.net/10016/20071Understanding the emergence of cooperation is a central issue in evolutionary game theory. The hardest setup for the attainment of cooperation in a population of individuals is the Public Goods game in which cooperative agents generate a common good at their own expenses, while defectors "free-ride" this good. Eventually this causes the exhaustion of the good, a situation which is bad for everybody. Previous results have shown that introducing reputation, allowing for volunteer participation, punishing defectors, rewarding cooperators or structuring agents, can enhance cooperation. Here we present a model which shows how the introduction of rare, malicious agents &- that we term jokers &- performing just destructive actions on the other agents induce bursts of cooperation. The appearance of jokers promotes a rock-paper-scissors dynamics, where jokers outbeat defectors and cooperators outperform jokers, which are subsequently invaded by defectors. Thus, paradoxically, the existence of destructive agents acting indiscriminately promotes cooperation.7application/pdfeng© Elsevier Ltd.Public goodsCooperationDestructive agentsCyclesresearch articleMatemáticas10.1016/j.jtbi.2011.03.017open access1131119Journal of theoretical biology279AR/0000010596