title: Cheating is evolutionarily assimilated with cooperation in the continuous snowdrift game.
abstract: It is well known that in contrast to the Prisoner's Dilemma, the snowdrift game can lead to a stable coexistence of cooperators and cheaters. Recent theoretical evidence on the snowdrift game suggests that gradual evolution for individuals choosing to contribute in continuous degrees can result in the social diversification to a 100% contribution and 0% contribution through so-called evolutionary branching. Until now, however, game-theoretical studies have shed little light on the evolutionary dynamics and consequences of the loss of diversity in strategy. Here, we analyze continuous snowdrift games with quadratic payoff functions in dimorphic populations. Subsequently, conditions are clarified under which gradual evolution can lead a population consisting of those with 100% contribution and those with 0% contribution to merge into one species with an intermediate contribution level. The key finding is that the continuous snowdrift game is more likely to lead to assimilation of different cooperation levels rather than maintenance of diversity. Importantly, this implies that allowing the gradual evolution of cooperative behavior can facilitate social inequity aversion in joint ventures that otherwise could cause conflicts that are based on commonly accepted notions of fairness.
authors: Faculty of Mathematics, University of Vienna, 1090 Vienna, Austria; Evolution and Ecology Program, International Institute for Applied Systems Analysis (IIASA), 2361 Laxenburg, Austria. Electronic address: tatsuya.sasaki@univie.ac.at.
authors: Tatsuya
authors: T
authors: Sasaki
authors: Department of Business Administration, Soka University, 192-8577 Tokyo, Japan; Department of Information Systems and Operations, Vienna University of Economics and Business, 1020 Vienna, Austria.
authors: Isamu
authors: I
authors: Okada
mesh_terms: D005075:Biological Evolution; D003163:Competitive Behavior; D003299:Cooperative Behavior; D008192:Deception; D005716:Game Theory; D005717:Games, Experimental; D006801:Humans; D008962:Models, Theoretical
keywords: Adaptive dynamics; Evolution of cooperation; Evolutionary branching; Replicator dynamics; Snowdrift game; Speciation in reverse