Cooperation in Animal Societies explained by Game Theory
Charles Darwin’s theory of natural selection seems, at first glance, to encourage selfish behavior. “[N]atural selection is ruled by the survival of the fittest, so one might expect that selfish strategies benefiting the individual would be most likely to persist.” Interestingly, as the article states, it is possible for individuals to act in their own self-interest while still maintaining an overall cooperative community. This cooperation can be accurately explained by game theory, similar to what we learned in class.
One of the examples that the authors of the article raises is that of vervet monkeys. When a vervet monkey notices a predator nearby it begins to scream. While this draws attention to itself, it also warns other nearby monkeys of the presence of a predator. Given a monkey’s options in a single encounter with a predator (to scream or not to scream), at first it may seem obvious for the monkey to not scream and therefore not bring additional attention upon itself. But then why do they scream? The authors explain this by stating that it is not enough to look at just a single encounter; strategies change when analyzed across many encounters.
In a typical single encounter of the prisoner’s dilemma, “the best strategy is to defect – squeal on your partner and you’ll get less time.” However, across many encounters, the optimal strategy changes. This extends our class examples of game theory by considering multiple encounters instead of just one. Similar logic can be applied to the vervet monkeys example. In a single encounter it may benefit an individual monkey most if it remains silent but over time, but over many encounters it actually benefits the monkey most to alert the others as long as everyone follows this behavior. In other words, “each player has the incentive to defect, but overall they will do better if they cooperate.” This application of game theory leads to the rise of cooperation in animal societies.
Link:
https://www.quantamagazine.org/20150212-game-theory-calls-cooperation-into-question/