What role has altruistic behavior played in survival and prosperity during human evolution? This article explains how altruistic behavior has been maintained through the hypothesis of group selection, the impact of cooperation in groups on survival, and its limitations.
“Just one bite.” It’s hard to say no to a friend’s request to share some ramen noodles, even when you’re hungry. And if your friend is getting hit on the street, you’re tempted to run over and help, even if it means risking your own life. This is what we call “altruism,” the act of helping others, even at your own expense. Altruistic behavior is deeply ingrained in our lives, but it’s not easy to explain how it has been passed down and preserved over the course of human evolution. As a simple example, imagine an altruistic human and a selfish human living together in the distant past. The altruistic human would always try to help the selfish human, while the selfish human would only accept help. This means that the altruistic human would die early and be at an evolutionary disadvantage if he or she ran out of food or was exposed to danger. So how do we explain altruistic behaviors that remain after 2.3 million years of evolution?
One answer lies not in competition between altruistic and selfish individuals, but in competition between altruistic and selfish groups. Let’s look at this specifically. In the example above, we assumed that human survivability is determined by competition between altruistic and selfish human individuals. However, sometimes, due to war, climate change, etc., survival and death at the group level plays an important role in evolution, which is called the group selection hypothesis. In the previous example, we saw that in the case of individual selection arising from competition between individuals, selfishness is favored over altruism. But what about group selection?
First, consider the case of a war between two groups. If one of your coworkers is in danger from enemy soldiers, an altruistic person will sacrifice their own safety and run to help their coworker. Conversely, a selfish person would sacrifice their own safety for the sake of their teammate’s life. In the case of a selfish person, the individual makes the best choice for his or her own survival in the moment, but the result is that the death of a comrade weakens the force, increasing the likelihood that the entire group will be defeated and annihilated. In addition to this, in many situations in warfare, altruistic people are ready to sacrifice themselves for their team, so a team with more altruistic people is more likely to win the war. In other words, at the group level, altruistic people have a higher survival rate than selfish people. In fact, in ancient primitive tribes, tribal wars were common, and the losing side was often wiped out, lending support to the group selection hypothesis.
Second, humans have been hunter-gatherers for hundreds of thousands of years, and altruistic cooperation plays an important role in hunter-gatherer life. Let’s go back to the “just one bite” example from the beginning of the article. An altruistic tribe will not turn down a request for a bite when there is nothing to eat, and this is what keeps the whole tribe from starving. A selfish tribe, on the other hand, would starve to death if they were unsuccessful in a series of hunts. Also, finding food is not an easy task, so it’s in the best interest of the entire tribe to work together to find it. If each person hunts independently, their income will be limited to small animals, but if they work together, they can hunt larger animals. Therefore, the hunter-gatherer lifestyle increases the chances of survival for altruistic tribes.
This concept of group selection can also be found in modern society. For example, in times of crisis, such as natural disasters or pandemics, we have seen how altruistic behavior can increase the survival and well-being of a group. Many people have been seen to provide medical assistance or help neighbors in need, even at the risk of their own lives. While these behaviors can be viewed simply as individual moral choices, in a broader sense, they are part of a collective survival strategy that humanity has developed over a long evolutionary process.
These are two examples of situations that support the possibility of the collective selection hypothesis, but it’s not without its limitations. For collective selection to work, the rate at which altruistic humans are reduced by individual selection must be greater than the rate at which altruistic humans are increased by collective selection. In fact, many scholars have pointed out the practicality of the collective selection hypothesis due to this problem, and the following explanation attempts to overcome this limitation by using human “institutions” to overcome this limitation. If we have distributional systems that reduce income inequality in the modern world, ancient primitive tribes had food-sharing practices that allowed individuals to survive when food was scarce. In other words, institutions reduce the disparity between individuals, the rate of individual selection, and thus increase the relative influence of group selection.
We’ve explored one hypothesis for how human altruism, which is at first glance evolutionarily disadvantageous, has persisted. The group selection hypothesis states that altruism has been preserved at the group level because altruistic groups have a survival advantage over non-altruistic groups. The evolution of altruism, which could not be explained by competition between individuals, was explained in two contexts: warfare and hunter-gatherers. We also briefly discussed the limitations of the hypothesis and how to overcome them. It remains to be seen whether the group selection hypothesis is a good candidate to explain much of altruism, as there is still much debate and much to be explained. The evolution of altruism is more than just a theory, it provides important clues to understanding cooperation and interaction in human societies.
