Games and nets literature review

Ohtsuki, H., Hauert, C., Lieberman, E. & Nowak, M.A. A simple rule for the evolution of cooperation on graphs and social networks. Nature 441: 502-505 (2006). pdf

This is a simple exploration of how network structure -- in particular, connectedness -- affects the evolution of cooperation. They find that a good predictor for whether cooperation can invade and spread in a network is whether the benefit-cost ratio is greater than the (average) degree of the graph. They derive the result exactly for a cycle, approximately for a random graph where every node has the same degree, and use simulation to show that the fit is good for true random graphs and scale-free networks.

Santos, F.C., Pacheco, J.M. & Lenaerts T. Evolutionary dynamics of social dilemmas in structured heterogeneous populations. Proc Nat Acad Sci USA 103: 3490-3494 (2006). pdf

The authors show that heterogeneity in the degree of the graph (e.g. scale-free networks as opposed to single-scale networks) can encourage the evolution of cooperation. They simulate using what amounts to an imitation rule on a fixed network structure, and parameterize the game that is played so that it can represent three popular games: Stag Hunt, Hawk-Dove, and Prisoner's Dilemma.

Social Foraging

Rogers A. Does biology constrain culture? American Anthropologist 90(4): 819–831 (1988).

Rogers shows that in a population with both individual learning strategies and social learning strategies, assuming a fixed probability of environmental change in any given generation, the mixed evolutionarily stable strategy will be at a point at which the payoff from social learning exactly matches that of individual learning. Individual learning is assumed to have a constant, frequency independent payoff. He assumes individual learning to have a cost associated with it and social learning to be costless. The model has no space or other structure across which animals communicate.

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