Beyond the Prisoner’s Dilemma: Evolving Games and Why Populations Cooperate
It is no secret that humans cooperate with each other: cooperation is often beneficial to all parties that play along. Cooperation and game theory have long been studied hand-in-hand and we understand many situations where a human would follow the best decision for game theory. One of the most famous, if not the most famous, of these games studied is the Prisoner’s Dilemma. As we know, there is a Nash Equilibrium in the situation where both players decide to betray each other. To apply this interaction on a broader scale in order to understand how populations, however, is a little more difficult. Two major defining factors about populations interacting and cooperating is the fact that we have the ability to influence the payoffs of the game, and we have repeat exposures to the same players throughout our interactions. This is called an evolving game.
This study is an extension of what we have been learning in class. Games like the Prisoner’s Dilemma are the foundation for basic human interaction and cooperation between humans. We learned about choosing the best strategy for a single interaction, finding it out of a Nash Equilibrium. In an evolving game, however, players might want to try out different strategies over time, and see how both the player and the game react to it over time: everything is more dynamic. From this, scientists found that there was no strategy that always “wins.” The ranking and how well each player did was in constant flux. Both selfish strategies and cooperative strategies replaced each other over time as the most optimal strategies. Like in class, we try to find the best strategy for a game (or multiple games in this study), which in this case, is the one that dominates on average.
What was found in this study of evolving populations, usually cooperative strategies won out and dominated. This, however, depended on keeping the costs and benefits of cooperation fixed, which were more often than not, not fixed, due to the nature of the evolving game.
https://theconversation.com/new-take-on-game-theory-offers-clues-on-why-we-cooperate-38130
http://www.pnas.org/content/111/49/17558