title: Rewarding evolutionary fitness with links between populations promotes cooperation.
abstract: Evolution of cooperation in the prisoner׳s dilemma and the public goods game is studied, where initially players belong to two independent structured populations. Simultaneously with the strategy evolution, players whose current utility exceeds a threshold are rewarded by an external link to a player belonging to the other population. Yet as soon as the utility drops below the threshold, the external link is terminated. The rewarding of current evolutionary fitness thus introduces a time-varying interdependence between the two populations. We show that, regardless of the details of the evolutionary game and the interaction structure, the self-organization of fitness and reward gives rise to distinguished players that act as strong catalysts of cooperative behavior. However, there also exist critical utility thresholds beyond which distinguished players are no longer able to percolate. The interdependence between the two populations then vanishes, and cooperators are forced to rely on traditional network reciprocity alone. We thus demonstrate that a simple strategy-independent form of rewarding may significantly expand the scope of cooperation on structured populations. The formation of links outside the immediate community seems particularly applicable in human societies, where an individual is typically member in many different social networks.
authors: Department of Physics, Hong Kong Baptist University, Kowloon Tong, Hong Kong; Center for Nonlinear Studies and Beijing-Hong Kong-Singapore Joint Center for Nonlinear and Complex Systems, Institute of Computational and Theoretical Studies, Hong Kong Baptist University, Kowloon Tong, Hong Kong.
authors: Zhen
authors: Z
authors: Wang
authors: Institute of Technical Physics and Materials Science, Research Centre for Natural Sciences, Hungarian Academy of Sciences, H-1525 Budapest, Hungary.
authors: Attila
authors: A
authors: Szolnoki
authors: Faculty of Natural Sciences and Mathematics, University of Maribor, Koroška cesta 160, SI-2000 Maribor, Slovenia. Electronic address: matjaz.perc@uni-mb.si.
authors: Matjaž
authors: M
authors: Perc
mesh_terms: D005075:Biological Evolution; D003299:Cooperative Behavior; D005716:Game Theory; D056084:Genetic Fitness; D006801:Humans; D011157:Population Dynamics
keywords: Coevolution; Evolutionary games; Interdependent networks; Reward; Self-organization