The joker effect: cooperation driven by destructive agents

Alex Arenas (1) , Juan Camacho (2) , José A. Cuesta , Rubén Requejo (2)

1 Departament d'Enginyeria Informàtica i Matemàtiques
2 Department de Fisica

Understanding 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.

Mots clés: Public goods; Cooperation; Destructive agents; Cycles

Domaines: Sciences du Vivant [q-bio]

Alex Arenas, Juan Camacho, José A. Cuesta, Rubén Requejo. The joker effect: cooperation driven by destructive agents. Journal of Theoretical Biology, 2011, 279 (1), pp.113. ⟨10.1016/j.jtbi.2011.03.017⟩. ⟨hal-00694283⟩