In this blog post, based on “The Emergence of Altruistic Humans,” we will examine how the group selection hypothesis explains the evolution and existence of altruism.
In this day and age, when it is difficult to even take care of oneself, why do altruistic people exist? Is there a reason why I should live altruistically? There must be a good reason for people to live altruistically. Otherwise, people would make choices that are convenient for them in the moment and live selfishly. After reading “The Emergence of Altruistic Humans,” I chose the “group selection hypothesis” as the answer to why we should live altruistically. Let’s find out what the “group selection hypothesis” is and why it is a reason to live altruistically.
If a group of altruistic people and a group of selfish people go to war, most people would expect the altruistic group to win. This is because people’s actions for the group increase the group’s competitiveness. Not only in war, but also in countless other survival competitions, groups with many altruistic people would have an advantage. If such competition for survival has continued since the dawn of humanity, and if altruism is a trait that can be passed down genetically, then the proportion of altruistic individuals should increase over time. The phenomenon whereby individuals and groups with traits that are advantageous for survival survive and leave more offspring, thereby increasing the proportion of individuals and groups with those traits, is called natural selection. For example, if individuals or groups that are smart and strong compete for limited resources in the same environment, the former will survive and leave more offspring. This will be repeated over many generations, increasing the proportion of people who are strong and smart. Among natural selection, natural selection for groups is called group selection. The above explanation can also be considered group selection. The hypothesis that the number of altruistic people has increased due to this group selection is called the group selection hypothesis in “The Emergence of Altruistic Humans.”
However, this hypothesis cannot be explained so easily. This is because natural selection includes not only group selection but also individual selection. If altruistic people and selfish people compete, who will survive? Let’s set up a situation to answer this question. A selfless person A and a selfish person B, who are both in the same physical and mental condition, live in the same group. A distributes food to people when it is available, while B stores all of it in his warehouse. If a situation arises where food suddenly becomes unavailable, B is much more likely to survive than A. Not only in this situation, but in countless other situations, selfish people are clearly more likely to survive than altruistic people, and are also more likely to leave descendants. Here we can see a conflict between group selection and individual selection. Group selection tends to favor altruistic humans, while individual selection tends to favor selfish humans.
However, this does not mean that the group selection hypothesis is an unreasonable explanation. Consider a tug-of-war. Two teams are clearly pulling in opposite directions. Does this mean that the rope will remain in place? No, it will not. The rope will be pulled in the direction of the team with more strength. In this context, group selection and individual selection can be thought of as a tug-of-war. If group selection is stronger, there will be more altruistic humans, and if individual selection is stronger, there will be fewer altruistic humans. It is not easy to prove that group selection is stronger than individual selection, but the author of “The Emergence of Altruistic Humans” argues that group selection clearly has an influence on the evolution of altruistic humans.
So far, we have explained the meaning of group selection, the meaning of individual selection, the definition of the group selection hypothesis, and the limitations of the group selection hypothesis. Although there are clear limitations to the group selection hypothesis, it presents a reason why we should live altruistically. In order for the group to which we belong to survive, each individual must live altruistically. Of course, there is plenty of room for refutation of this hypothesis. This is because of the conflict with individual selection mentioned earlier. However, through further experiments and observations, this theory is likely to become a more logically complete explanation.
