Why do humans act altruistically, and what is the evolutionary background?

This article explains why humans behave altruistically from an evolutionary biology perspective, analyzing it through the iteration-reciprocity hypothesis and kin selection theory. It discusses how altruistic behavior stems from social norms and a sense of moral obligation, and is an important factor in increasing social trust and cooperation, which contributes to the well-being of society as a whole.

 

Most of us in society have a natural tendency to help others and work together. We have a basic sense of altruism, and we know that altruistic behavior doesn’t benefit us in and of itself. But we’ve probably never stopped to think about why we act altruistically. This question has been studied and debated for a long time in evolutionary biology, sociobiology, and other fields. This has led to the emergence of hypotheses, or theories that explain why we act altruistically. One of these is the reciprocity hypothesis, which states that humans act altruistically because we receive as much as we give.
According to this hypothesis, humans act altruistically toward others in anticipation of future altruistic behavior by treating their own future rewards as an insurance policy. If the other person is not acting altruistically, but is acting solely in their own best interest, then they can pursue their own self-interest in the next situation. In conclusion, the reciprocity hypothesis states that alternating altruistic behaviors leads to repeated altruistic behaviors because it is more beneficial to both parties than to pursue their own self-interest alone.
Another hypothesis that explains why humans engage in altruistic behavior is kin selection theory. This theory states that we act altruistically to increase the chances of our genes surviving. In other words, helping relatives who carry your genes to increase their chances of surviving and reproducing is ultimately beneficial to your own genetic survival. This theory of kin selection provides important clues to understanding human altruistic behavior from an evolutionary biology perspective.
There is also a view that human altruism stems from social norms or a sense of moral obligation. As social animals, we adhere to social norms and moral codes to maintain our social status and promote trust and cooperation within society. This sense of social norms and moral obligation drives us to act for the good of the community, which transcends our individual interests.
Suppose I want to eat half a chicken because it’s too much for me to eat a whole chicken. But if a whole chicken is usually full, half a chicken costs a little more than 5,000 won. Let’s say it’s $6. If I buy a whole chicken and split it with a friend, I’m $4,000 worse off than if I buy a half chicken and eat it alone. But if my friend buys another chicken and splits it with me, I’ve gotten $6,000 worth of chicken for free, so I’ve gained $2,000 and my friend has gained $2,000. However, if someone buys a whole chicken and doesn’t share it, but only buys enough for themselves and half a chicken, then in the next situation, it would be ideal for the other person to also buy enough for themselves, so that both parties don’t lose. Comparing the two situations, it would be most beneficial to alternate buying one chicken each. This is the reciprocity hypothesis, which states that altruistic behavior in anticipation of future benefits (e.g., “I bet she’ll be nice next time!”) leads to altruistic behavior from the other person.
There’s a problem with this hypothesis. If there is a fixed point at which chicken is no longer available, and both people know that point, neither of them will want to hurt themselves by buying one chicken at the last minute. Furthermore, if the other person knows that the person who buys the chicken at the last minute will only buy half a chicken, he or she will also only buy enough chicken to eat at the point just before the last minute. This hypothesis therefore requires that the chicken-buying situation must be repeated over and over again, i.e., that the situation in which altruistic behavior is possible must be repeated.
Repetition and reciprocity have led to human altruism. However, the hypothesis is limited if there is an end to this repetitiveness. However, even though there may be a limit to the repetitiveness of certain behaviors, the story is different if we think of repetitiveness and reciprocity not necessarily as one-to-one repetitiveness and reciprocity, but as repetitiveness between and within groups. On a broader scale, just as the future is unpredictable, human behavior itself has no limits. Therefore, a broader view of iteration and reciprocity would compensate for many of the limitations of the theory. In conclusion, we can say that the repetition-reciprocity hypothesis is a hypothesis that explains how human beings have developed and influenced altruistic behavior in such a way that they have come to engage in altruistic behavior with all members of society.
In social life, altruistic behavior is an important factor that promotes the harmony and development of society as a whole, not just individual interests. Increased altruistic behavior increases social trust, enhances cooperation and mutual support, which in turn improves the welfare of society as a whole. In this context, understanding and encouraging altruistic behavior in humans is a crucial task.
Finally, altruistic behavior is a complex phenomenon that cannot be explained by mere theoretical hypotheses. We constantly experience altruistic behavior in our daily lives, and it deeply connects us to others. These experiences form a fundamental part of human nature and make us reflect deeply on why we all help each other and live. Altruistic behavior is therefore an important act that reflects an essential aspect of human existence.