How Game Theory Explains Altruistic Animal Behavior
As a Human Development major, most of my classes encompass hard science: biology, neuroscience, chemistry, etc. I wanted to see how the notion of game theory could be applied from a biological perspective, via the avenue of evolutionary game theory. One of the theories discussed in class can be applicable from the most mundane to the most complicated situations we face: game theory. Traditional game theory is defined as the analysis of strategies for responding to competitive situations where the outcome of a player’s choice of action depends crucially on the actions of the other players. Optimally, we want to establish a Nash equilibrium in these situations, where all players are utilizing a Nash strategy. Simply put, a Nash strategy is the aim of doing what is best for yourself, given what others around you are doing. Essentially, it is the best response to a situation that yields the highest payoff or greatest benefit.
This article discusses how evolutionary game theory provides a rationale for why some animals act altruistically– in which an individual reduces its own “fitness probability” (i.e. ability to survive and reproduce) to improve the fitness probability of another individual or group. As game theory assumes each individual will tend to act in its own self-interest, the concept of altruism seems to contradict this assumption. The rationale of evolutionary game theory explicates that animals/organisms act altruistically because they expect reciprocal altruism, in which the benefits they provide to others will be returned to them in the future. One specific example of this is in the case of robins, which emit high-pitched warning calls in the presence of danger. A bird that provides a warning call is temporarily more apparent to predators, thus reducing its immediate fitness probability. However, the same bird may benefit in the future from warning calls from other birds. In a single encounter, it may provide the greatest benefit to an individual bird if it remains silent but over time, over many encounters, it actually benefits the bird most to alert the others as long as everyone follows this behavior. Each player has the incentive to defect, but overall they will do better if they cooperate, or act altruistically. This application of evolutionary game theory leads to the rise of cooperation and altruism in animal societies.