This blog post examines the evolutionary reasons and social mechanisms that have allowed altruistic behavior to survive and thrive in society despite being disadvantageous to the individual.
In our human society, we often see people acting in a cooperative manner. In addition, altruistic behavior is also found in various animals such as ants, bees, meerkats, vampire bats, and chimpanzees. Altruistic behavior refers to helping others at the expense of oneself. In other words, individuals suffer losses through altruistic behavior, but would any person deliberately create a situation that causes them losses?
It is easy to intuit that altruistic behavior is unlikely to exist. One of the logical models that explains this is the “prisoner’s dilemma” game. Two people have been arrested as suspects in a case, and the police can only solve the case if they confess. The police take the two men to different interrogation rooms and offer them a deal. If both men confess, they will each be sentenced to five years in prison. If both men deny the crime, they will each be sentenced to one year in prison. If one confesses and the other denies the crime, the one who confesses will be released and the one who denies will be sentenced to seven years in prison. From the perspective of both of them, the best strategy is to confess, but in reality, the best situation was when neither of them confessed (each received a one-year sentence). This is why it is called the Prisoner’s Dilemma. In other words, altruistic or cooperative behavior is never a good strategy for an individual. Then, the question arises as to how altruistic behavior can exist in society.
Let’s explain this problem through the phenomenon of “people with similar characteristics gathering together.” If we create a new game in which altruistic and selfish behaviors interact, then when altruistic people meet, they each receive a reward of 1. This is defined as cooperation. On the other hand, if an altruistic person meets an egoistic person, the altruistic person receives a reward of -1 and the egoistic person receives a reward of -2. This is defined as betrayal (the result of a selfish person’s betrayal). And if you set the reward to zero when meeting selfish people, you can see that, like the prisoner’s dilemma, altruistic behavior is never a good strategy, and betrayal is the best strategy.
Let’s look at how altruistic behavior can exist based on this game. If traders use cooperation or betrayal as a strategy, the trader who chooses betrayal as a strategy will eventually benefit more than the trader who chooses cooperation as a strategy. Therefore, traders who choose cooperation will find it difficult to survive. However, traders who choose cooperation can receive higher rewards when trading with each other than when trading with traders who choose betrayal. Since a betrayal strategy can only reap high profits when the other party cooperates, an environment that is favorable to altruistic people will be created if altruistic people gather and interact with each other. If altruistic people gather in this way, it will be possible to explain how altruistic behavior is widespread in society.
According to the research of sociologists and biologists, Jared Diamond has found that people tend to choose a partner who has similar religious or political views to them. He says that we consider religion and political views to be important factors when choosing a partner or making friends. Whether a person is altruistic or selfish is a cultural and behavioral trait, and research on diamonds suggests that similar people tend to gather together. People who grew up in the same cultural background can gauge each other’s tendencies to some extent through each other’s speech, facial expressions, and behavior. If we can identify whether the other party is altruistic or selfish before we make a deal, then altruistic people will eventually look for and make deals with other altruistic people like themselves, so it is likely that similar people will gather together. This means that altruistic people will survive and be found in society.
However, the phenomenon of “people with similar characteristics gathering together” is often used as a negative expression, “like their own kind,” and is sometimes interpreted as a critical nuance. As the frequency of the phenomenon of people with similar characteristics gathering together increases, the number of altruistic people increases and can have a positive impact on society, but this may reduce the benefits of diversity. Of course, the heterogeneity that comes from selfish tendencies is less likely to bring about positive diversity, but it is easy to understand the negative aspects of this phenomenon if you imagine a village made up of only good people. For example, the idea of inventing a machine to make work easier may not come to mind.
I have explained how altruistic behavior has existed despite being considered evolutionarily unstable, and how altruistic people tend to gather together with similar people. In the game above, altruistic behavior is not the best strategy for an individual when traded with selfish behavior, but when traded with similar people, altruistic behavior is a sufficiently advantageous strategy and can thrive. This is because it is possible for altruistic people to come together in society, and this phenomenon can occur among similar people. There may be drawbacks to the phenomenon of altruistic people coming together in society, but society is large and altruistic people also have various characteristics, so this phenomenon will not cause major problems. Furthermore, if such a phenomenon of similar people gathering together leads to more altruistic people and everyone helps each other, it will be possible to create a situation where transactions made with a cooperative strategy, like the game described above, benefit everyone.
