Last year, University of Pennsylvania researchers Alexander J. Stewart and Joshua B. Plotkin used game theory approach to explain why cooperation and generosity have evolved in nature.
But now they’ve come out with a somewhat less rosy view of evolution. With a new analysis of the Prisoner’s Dilemma played in a large, evolving population, they found that adding more flexibility to the game can allow selfish strategies to be more successful. The work paints a dimmer but likely more realistic view of how cooperation and selfishness balance one another in nature.
Their study examines the outcomes of the Prisoner’s Dilemma, a scenario used in the field of game theory to understand how individuals decide whether to cooperate or not. In the dilemma, if both players cooperate, they both receive a payoff. If one cooperates and the other does not, the cooperating player receives the smallest possible payoff, and the defecting player the largest. If both players do not cooperate, they both receive a payoff, but it is less than what they would gain if both had cooperated. In other words, it pays to cooperate, but it can pay even more to be selfish.
In the new investigation, Stewart and Plotkin added a new twist. Now, not only could players alter their strategy — whether or not they cooperate — but they could also vary the payoffs they receive for cooperating.
“After this study, we end up with a less sunny view of the evolution of cooperation,” Stewart said. “But it rings true that it’s not the case that evolution always tends towards happily ever after.”
Reference: https://www.sciencedaily.com/releases/2014/11/141124152556.htm
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