Evolutionary Altruism
Concepts of game theory, Nash equilibria and evolutionary equilibria have direct correlations with the natural world. Specifically, animal interactions can be treated as games, gene types as strategies, and the likelihood of survival through natural selection as payoffs. This framework is interesting not only as an application of game theory, but as a means to answer some evolutionarily puzzling questions. For instance, how did the concepts of cooperation and altruism develop in through natural selection? If individual survival is all that really counts, what could motivate a desire to help and cooperate with others?
Most often, this phenomenon is explained by the theory of “reciprocal altruism”- that is, when an animal goes out of its way to help another, it is likely that such behavior will be reciprocated by others in the future. In terms of game theory, even though this animal receives a lower payoff in this game, it is likely to be better off in the long run. This is because the game is repeated over and over with the same players. Due to this, cooperation is an evolutionary stable strategy. The article explains this by relating the situation to the ‘Iterated Prisoners Dilemma’—in which the same convicts are arrested together multiple times. Though the convicts may be tempted to defect initially, in the long run, a cooperation strategy is far more likely to evolve.
As we can see from the plot above, the likelihood of an offensive or ‘tit-for-tat’ strategy falls over time. This explains why cooperative behaviors, which seem to go against the very idea of natural selection, can arise naturally in the real world.
Article in Nature Education: