Evolution of cooperation and lack of universality in game theory on graphs
By: Anxo Sanchez
From: GISC/Matematicas, Universidad Carlos III de Madrid, Spain
At: Complexo Interdisciplinar, Anfiteatro
[2009-05-13]
In the past few years much work has been devoted to understanding the emergence of cooperation through network reciprocity, i.e., by studying evolutionary games among individuals whose interactions are governed by a network. While this line of research has produced a number of interesting and inspiring results, a complete picture of the observed phenomenology and the mechanisms behind it is lacking. In this talk, we will provide evidence that such a complete picture can not be found because evolutionary game theory on graphs is highly non-universal. Our research focuses on the case of degreehomogeneous networks such as lattices, Erdos-Renyi random graphs and others. Extensive simulations allow us to conclude that the enhancement or inhibition of cooperation strongly depends on the type of network, the type of evolutionary dynamics and the social dilemma under study. Furthermore, the phenomenology observed in real social networks may be considerably different from the results of this kind of models. In particular, the existence of a mesoscopic level of organization can not be neglected. We also show that the formation of the network itself through coevolution with the game may be another relevant factor. Our main conclusion is that modeling the emergence of cooperation in a sensible way requires looking at wide range of social dilemmas and not at a particular one, and that this research should always have in mind a specific context for application because of the lack of universality.