In this blog post, we will look at the reasons why altruistic behavior is advantageous for survival, focusing on evolutionary theory and the group selection hypothesis.
Altruistic behavior refers to actions that sacrifice oneself for the benefit of others. Examples of such behavior can be easily found in the news, such as collecting donations and volunteering for people in countries affected by natural disasters such as earthquakes and tsunamis, or saving people who are about to fall onto train tracks, sacrificing one’s own life in the process. So what is the cause of altruistic behavior? From an evolutionary perspective, altruistic behavior is not at all advantageous for survival. Living things try to behave in ways that are advantageous for their survival and evolve accordingly. This is what we know as the theory of evolution.
If acting solely for one’s own benefit is more advantageous for survival than helping others, why do we engage in altruistic behavior? Is it because of the moral education we received from childhood, such as “You must live a good life” and “You must be considerate and helpful to others”? If altruistic behavior is a phenomenon unique to humans, it could be explained by education. However, altruistic behavior is not unique to humans. It is commonly found in other animals, such as worker bees that work their entire lives for the queen bee, and vampire bats that share the blood they obtain with their fellow bats that have failed to hunt. So why do they behave altruistically, even at the risk of their own survival, when it is not enough to act in their own best interests?
One hypothesis that can answer this question is the group selection hypothesis. Before explaining the group selection hypothesis, let’s first look at evolution. The universal theory of evolution is natural selection. It states that characteristics that are most suited to the environment survive, while those that are not disappear. Let’s imagine people whose arms cannot bend. Because their arms cannot bend, these people will starve unless someone helps them. In this situation, people with altruistic tendencies will help others, while those with selfish tendencies will simply accept food from others. In this case, people with selfish tendencies would have a greater chance of survival. The important point to note in this example is that selfish tendencies are not a characteristic of the group, but of the individual. As individual characteristics are advantageous for survival, individuals with advantageous characteristics survive, while those without advantageous characteristics are eliminated and disappear. In other words, the universal process of evolution is individual selection.
However, group selection means that the process of natural selection described above occurs not only for individuals but also for groups. The survival probability of a group varies depending on what characteristics the group has or how many individuals with certain characteristics it has, and the process by which those characteristics spread throughout the group or disappear is called group selection. As defined above, altruistic behavior refers to behavior that sacrifices oneself for the benefit of others. According to this definition, the more individuals who engage in altruistic behavior, the higher the probability of survival compared to smaller groups.
Let’s look at an example to explain how altruistic behavior can increase the survival rate of a group. Let’s think about the Zerg in StarCraft, a game we enjoyed playing when we were children. Among the Zerg units, there is a unit called the Defiler. The Defiler is a unit that reduces damage to allies and damages opponents through various skills. In order to use these skills, mana is required, and the skill that restores mana is called Consume. Consume is a skill that restores mana by sacrificing allied units. After restoring mana by sacrificing allies, it reduces damage to other allies, ensuring their victory and survival. This can be considered an example of the group selection hypothesis, as the sacrifice of allies for Consume increases the survival rate of the group as a whole. This example is not limited to virtual reality. In actual warfare, it is even more obvious that altruistic behavior increases the victory and survival rate of allies. Risking one’s own life to infiltrate enemy territory to assassinate leaders or conduct intelligence activities can be the key to victory in war. Such behavior can be considered altruistic behavior for the sake of the victory of allies in a situation where one’s own life may be lost.
However, if a group consists only of individuals who act selfishly, that is, for their own benefit, victory cannot be guaranteed compared to a group that acts altruistically, and as a result, the survival rate of the group will be lower. Therefore, the more individuals who act altruistically, the higher the survival rate compared to groups that do not. As altruistic groups are more likely to survive than non-altruistic groups, natural selection occurs, which explains why altruistic behavior emerges through this process.
However, this alone does not fully explain the emergence of altruistic behavior. The problem of speed is one of the arguments against the group selection hypothesis. The problem with speed is that the speed of group selection cannot keep up with the speed of individual selection. This means that compared to the speed at which an individual learns the success strategies of others, the speed at which a selfish group learns the tendencies of an altruistic group is ridiculously slow. To solve this problem, humans introduced the concept of “institutions,” which slow down the speed of individual selection and speed up the speed of group selection, and have developed based on this concept.
For example, by establishing a system that encourages and rewards altruistic behavior through social institutions and norms, altruistic behavior has become more frequent. Such institutional mechanisms include laws, education, and culture, and have a structure that ensures that individuals receive positive rewards for altruistic behavior. This is an important factor in ensuring that altruistic behavior is not simply a moral choice of individuals, but a social survival strategy.
The group selection hypothesis explains why altruistic behavior exists using the examples of StarCraft and war. The more people who are willing to sacrifice themselves for the group, the higher the prosperity and survival rate of the group, and thus altruistic behavior emerged because it is more advantageous for survival than selfish behavior. However, the group selection hypothesis alone cannot fully explain the emergence of altruistic behavior. To resolve this, the concept of “institutions” was introduced. The history of humankind has developed based on these “institutions,” so the group selection hypothesis is not meaningless just because it cannot solve the problem of speed. In addition, the group selection hypothesis can explain altruistic behavior toward strangers, which cannot be explained by the kin selection hypothesis, and altruistic behavior in situations where there is no reciprocity or repetition, which cannot be explained by the repetition-reciprocity hypothesis. Therefore, it can be said that it is a sufficiently influential hypothesis.
