section_path: Evolutionary approach
section_name: Evolutionary approach
paragraph_text: Evolutionary approach
  
  Evolutionary approaches to understanding friendship focus primarily on its function. In other words, what does friendship do for individuals, how does it work psychologically, and how do these processes affect people's actual behavior. Within this field, there are multiple proposed theories or perspectives about the function of forming friendships and making friends. One is the theory of Reciprocal Altruism which provides an explanation as to why individuals make friends with un-related others. It argues that friendship allows people to exchange benefits with each other and keep track of these exchanges in order to avoid exchanging benefits with a poor cooperator, or someone who will take benefits without giving any in return. Another perspective likens friendships to insurance investments and argues when deciding to invest into forming a new friendship with another person an individual should be able to discern: whether the potential friend will be willing to help them back in the future, if the potential friend is in the position to help them in the future, and if the friendship is worth continuing or not, especially when many other potential friendships can be made. These factors will determine whether forming a friendship with someone will be beneficial or injurious. Another explanation for the function of friendships is called the Alliance Hypothesis which argues that the function of friendships is to acquire alliances for future conflicts or disputes. The Alliance Hypothesis states that conflicts typically can be won if and only if one side is able to acquire more allies than the competing side, all else equal, so individuals should be able to increase their odds of winning the conflict if they are able to recruit more alliances to their side. Choosing your allies can be very important and there exists a variety of methods in deciding allies such as bandwagoning or choosing an ally that is loyal and will come to your aid in the future conflicts. Thus, individuals should form alliances (i.e., friendships) with people that ranks themselves higher than other allies/friends. It is relative rank (i.e., where the self ranks among all other individuals) that is the most important contributing factor when deciding who is a loyal ally and friend.