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Evolutionary Psychology
Why Helping Other People Also Helps You
The sacrifices made by prehistoric humans created nicer 21st-century people.
Updated February 15, 2024 Reviewed by Monica Vilhauer
Key points
- Altruistic behavior has long posed a problem for evolutionary scientists.
- Belief that individuals sacrifice for the good of the species has been rejected by evolutionary scientists.
- Multilevel Selection Theory explains how sacrificing for a group can lead to evolutionary change.
Natural selection has often been mischaracterized as operating for the “good of the species” and depicted as species being pitted against each other for survival like athletic teams knocking each other out of the playoffs. Consequently, species were thought to “improve” through the process of evolution, and individual organisms evolved to make great sacrifices, even to the point of giving their lives, so that the species might live on.
This theoretical perspective is commonly referred to as “group selection.”
How Do Evolutionary Psychologists Feel About Group Selection?
Group selection is now unanimously rejected by evolutionary scientists. Individuals do not act for the good of the species; in fact, other members of our species are our fiercest competitors, and it is precisely this within-species competition that drives evolution. There would be no advantages for a selfless individual who engaged in self-sacrificial behavior without some personal payoff, so the genes associated with completely selfless behavior would have been eliminated from the population in short order.
Evolutionary scientists have developed multiple explanations to help us understand why individuals behave generously and helpfully. We help relatives who share our genes (kin selection) even when it costs us, because if the relatives successfully pass along their genes, well, those are our genes as well. We also help others who are in a position to help us back (reciprocal altruism), and we may engage in very costly or even heroic altruistic behavior (costly signaling) as a way of advertising good qualities about ourselves, making us desirable as a mate or ally in the eyes of others.
But evolution can also work in more subtle ways, and researchers such as evolutionary biologist David Sloan Wilson believe that groups can indeed be vehicles for natural selection, but not in the simple-minded “for the good of the species” manner that the original group selectionists proposed.
This perspective has come to be known as “Multilevel Selection Theory.”
According to multilevel selection theory, evolution can favor traits that increase the fitness of groups as they compete with other groups around them, and if the group succeeds, this success can trickle down and benefit everyone in the group as well; maybe a rising tide really can lift all of the boats. Wilson has used multilevel selection theory as a framework for understanding things such as why some religions and cults thrive and grow while others simply fade away after a brief period of prosperity.
How Does “Multilevel Selection Theory” Work?
To help us envision how a trait such as altruism might evolve in this way, let’s consider a hypothetical prehistoric group of humans that I will call the “Freds.”
Let us imagine that the Freds are a group of mostly generous, altruistic people. There are plenty of men who are willing to share meat with other families following particularly successful hunts, and there are many women who are generous with their time and resources in helping other women with child care. Often, these individuals may be helping relatives with whom they share genes, but they also freely help others with whom they are friendly. Although people within this society are still competing with each other, there is a high level of trust among them and people regularly make small sacrifices for the good of others in the group.
When things get tough and the group faces a famine or an attack from a rival group, their cooperative tendencies help them pull together, coordinate their efforts, and weather whatever storm has come their way.
Now, imagine a rival group that covets the hunting grounds currently occupied by the Freds; let’s call them the “Barneys.” The Barneys are willing to go to war with the Freds to get what they want, but the vibe in their tribe is quite different. The Barneys are primarily made up of selfish individuals who do not trust each other. Altruists have long ago been weeded out of the group by unscrupulous strivers, and they are almost as wary and untrusting of each other as they are of their enemies in other groups.
Because they do not play together well, the Barneys go into battle more as a collection of self-interested individuals rather than as a well-functioning team that is keeping its eye on the prize of what will ultimately be good for the group as a whole. Few of the Barneys are willing to put their lives on the line for their comrades and women, which is something that the Fred warriors do without thinking. When the groups inevitably clash, it quickly turns into a rout. The Barneys cut and run for their lives because they are unprepared for the unified, coordinated defense of the Freds.
The Barneys will be equally ill-prepared to deal with other calamities. Unaccustomed to sharing and trusting each other, each famine and other natural disaster will turn into an every-man-for-himself apocalypse that splinters the group and makes it completely dysfunctional. Over the long frame of evolutionary time, selfish groups like the Barneys produce fewer successful offspring than cooperative groups like the Freds, and the proportion of Barney genes in the population decreases while the Fred genes explode. As a result, there come to be more cooperative, altruistic people in the population as a whole.
Thus, making sacrifices for the good of the group can be an adaptive trait as long as the sacrifice ultimately leads to long-term benefits for the individual.
It is important to point out that multilevel selection theory is far from universally accepted by evolutionary psychologists. Many critics concede that it might be theoretically possible for it to work, but believe that the conditions necessary for it to operate in the real world occur so rarely that it simply does not happen. Other critics reject it because it is nothing more than an attempt to bring back old-fashioned group selection ways of thinking. Nevertheless, multilevel selection theory offers an interesting and unique way of thinking about a wide range of different human social behaviors, and the final word on its value awaits the efforts of future researchers.
