In this blog post, we will examine how altruistic behavior is maintained in the theories of natural selection and group selection, and what role institutions and culture play in its continuation.
In ancient times, there were giraffes with short necks and giraffes with long necks. In order for giraffes to survive, they must be able to easily eat food located high up, so giraffes with long necks are better suited to survival. Over many years, through countless competitions and evolution, giraffes with long necks eventually thrived. Everyone has heard this story before. This is one of the most representative examples of “natural selection.” Natural selection means that the characteristics most suited to the environment at that time survive in that environment. Over time, the number of individuals with the most suitable characteristics generally increases, while the number of individuals without those characteristics decreases.
Let’s look at another example to understand the concept of natural selection. The finches of the Galapagos Islands developed different beak shapes depending on the environment of each island. On some islands, birds with strong beaks were advantageous for eating hard seeds, while on other islands, sharp, thin beaks were necessary for catching small insects. In this way, individuals that adapted to their environment survived and reproduced, passing on their characteristics to their offspring. This process clearly illustrates the core principle of natural selection.
Let’s consider natural selection as it applies to individuals. When a trait is well suited to a culture, the number of individuals with that trait increases. This is called “individual selection.” Let’s apply this to selfishness and altruism. First, altruistic behavior is inevitably less successful than selfish behavior. This is because altruistic behavior is an act of helping others at the expense of oneself, and compared to selfish behavior that only benefits the individual, the losses outweigh the gains. Therefore, according to the theory of natural selection, the number of individuals who engage in altruistic behavior should gradually decrease. However, as we can see in today’s society, altruistic behavior can often be found around us. The reason why altruistic behavior occurs in society despite being disadvantageous in natural selection is because it is directed at individuals.
Therefore, we introduce the theory of “group selection,” in which characteristics that are suitable for a group survive longer. As a simple example, suppose there are two villages, one with many altruistic people and the other with many selfish people. Over time, if they experience many difficulties such as natural disasters and wars, the altruistic village will help each other and solve the problems they face relatively easily, so the altruistic village will survive longer. Thus, according to the theory of individual selection, individuals with altruistic tendencies will gradually disappear, but according to the theory of group selection, individuals with altruistic tendencies will gradually increase.
In theory, group selection can be explained as a mechanism that maintains altruistic behavior, but in reality, individual selection is more likely to act faster. Then, we need to consider which theory causes the selection process to occur faster, that is, the issue of speed. If individual selection is faster, altruistic individuals will gradually decrease, and if group selection is faster, altruistic individuals will gradually increase. However, in general, group selection, which involves a large number of subjects, cannot catch up with individual selection.
Nevertheless, how can we explain the survival of altruistic individuals? This can be explained by increasing the speed of group selection and slowing down the speed of individual selection, and it is “institutions” that play this role. Suppose two people are playing a game. If person A wins all 100 games out of 100, most people will want to know A’s strategy and follow it. On the other hand, if Person A wins 55 out of 100 games due to some restriction and the opponent wins 45 games, fewer people will follow Person A than in the previous situation. Let’s look at another example. Consider an agricultural society in a natural state without any institutions. As time passes, the prosperity of selfish individuals will lead to widespread inequality, creating a vicious cycle that will cause altruistic individuals to disappear. However, the gap between selfish and altruistic individuals can be reduced through joint ownership of resources and food sharing, which function as income redistribution policies. In other words, the speed of individual choice is slowed down. The key point is that if the gap between people can be reduced through social institutions and services, the pressure of individual choice will be reduced, and the rate at which people with altruistic behavior strategies disappear will slow down.
There is something that plays a role similar to that of “institutions,” and that is “conformist cultural transmission.” In the example in the previous paragraph, it is easy to accept that most people follow the dominant person. Let’s call the dominant person, the person we aim to follow, a “model.” As we saw in the previous example, we generally set a model and follow it if its strategy is superior. At this point, the results will differ depending on how the model is set. If we assume that the model is set randomly, the ratio of people with a certain strategy and people who choose that strategy as their model will be constant. However, we never set models randomly, but rather with some bias. In other words, if more than half of the people have a certain strategy, the percentage of people who choose that strategy as their model will be higher than that percentage, and conversely, if less than half of the people have that strategy, the percentage of people who choose it as their model will be lower than that percentage. To explain this with a simple example, when a majority votes for one item in a public vote, those who did not vote are more likely to vote for that item. This is called “conformist cultural transmission.” Applying this to altruism, if more than half of the individuals in a group are altruistic, altruistic behavior will flourish more quickly in that group, which means that the effect of group selection will be greater.
Furthermore, in human society, the development of language and communication plays an important role in the spread of altruistic behavior. Through language, we can praise altruistic behavior and convey the importance of altruistic behavior through stories. This has a significant impact on strengthening altruistic behavior within a group. For example, if people hear stories about helping those in need within their community and those actions are respected, others will imitate those behaviors.
So far, we have learned how altruistic behavior, which at first glance seems impossible to survive, continues through group selection theory. If you were in their shoes, would you follow the selfish person or the altruistic person? What would be the result of your choice? I hope this article has given you food for thought. I would like to remind you once again that altruistic behavior goes beyond individual survival strategies and has a significant impact on the survival and prosperity of the society and community to which we belong.
