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arXiv · 0906.2046

Conformity Hinders the Evolution of Cooperation on Scale-Free Networks

Jorge Pena·Henri Volken·Enea Pestelacci·Marco Tomassini
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Abstract

We study the effects of conformity, the tendency of humans to imitate locally common behaviors, in the evolution of cooperation when individuals occupy the vertices of a graph and engage in the one-shot Prisoner's Dilemma or the Snowdrift game with their neighbors. Two different graphs are studied: rings (one-dimensional lattices with cyclic boundary conditions) and scale-free networks of the Barabasi-Albert type. The proposed evolutionary-graph model is studied both by means of Monte Carlo simulations and an extended pair-approximation technique. We find improved levels of cooperation when evolution is carried on rings and individuals imitate according to both the traditional pay-off bias and a conformist bias. More important, we show that scale-free networks are no longer powerful amplifiers of cooperation when fair amounts of conformity are introduced in the imitation rules of the players. Such weakening of the cooperation-promoting abilities of scale-free networks is the result of a less biased flow of information in scale-free topologies, making hubs more susceptible of being influenced by less-connected neighbors.

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Jorge Pena, Henri Volken, Enea Pestelacci, Marco Tomassini. 2009-06-11. Conformity Hinders the Evolution of Cooperation on Scale-Free Networks. https://doi.org/10.1103/physreve.80.016110

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