Selfless Genes: A New Revolution in Biology

Can selfless genes beat selfish genes?

Posted Apr 08, 2012

In the late 1960s and early 1970s evolutionary biologists celebrated a fundamental breakthrough. William Hamilton's inclusive fitness theory (aka selfish gene theory) indicated that organisms are narrowly "designed" to spread copies of their own genes, whether those genes are located in their own bodies or in the bodies of their relatives. Hamilton’s work seemed to show exactly how evolution worked, and also how it didn't work. Group selection, the idea that competition between groups of organisms shapes genomes, was declared dead. In effect, this defined altruism, real and authentic selflessness, out of existence. On a planet ruled by selfish genes, “altruism” was just masked selfishness. The biologist Michael Ghiselin expressed this beautifully, "Scratch an altruist and watch a hypocrite bleed."

The Selfish People

Let’s run a quick thought experiment to see how biologists reached this conclusion. Imagine that long before people spread out of Africa there was a tribe called The Selfless People who lived on an isolated island off the African coast. The Selfless People were instinctive altruists, and their world was an Eden.

The biological definition of selfishness: behavior that promotes one's own reproductive success.

The biological definition of selflessness: behavior that promotes someone else's reproductive success at the expense of one's own.

The single tribesman with selfish genes would--by definition--leave more descendants behind, eventually crowding altruistic traits out of the gene pool. The Selfless People would become The Selfish People.

The big 1960s breakthrough was simply this: selfish genes beat selfless genes; they beat them bloody; they beat them every single time.

The Selfless People

For a generation, this logic ruled evolutionary biology, and especially evolutionary psychology. But most of the biologists who were responsible for the 1960s breakthrough have gradually backed off their positions (the major hold out is Richard Dawkins, who writes that the "great heresy" of group selection "really is wrong").

Our thought experiment played out the way it had to. But that's because it had one unrealistic component: The Selfless People live in total isolation from all other tribes. And this isolation makes all the difference.

Now, let's run the thought experiment more realistically. This time the Selfless People live in a rich African valley that they share with another tribe. The two tribes frequently come into conflict over hunting grounds, old grudges, and insults barked across the river. And so the tribes fight, as tribes of men have always fought.

Imagine that the valley's second tribe is comprised mainly of selfish actors. Other factors held equal, who wins: the tribe of self-sacrificing altruists or the tribe where every warrior is looking out for number one? Won't it be the Selfless People? Won't the Selfless People tend to dominate selfish tribes in most competitive situations? And, as a result, won't selfless genes proliferate? 

Charles Darwin thought so. In The Descent of Man, Darwin ran his own thought experiment, pitting selfless against selfish tribes:

"It must not be forgotten that although a high standard of morality gives but a slight or no advantage to each individual man and his children over the other men of the same tribe, yet that an advancement in the standard of morality and an increase in the number of well-endowed men will certainly give an immense advantage to one tribe over another. There can be no doubt that a tribe including many members who, from possessing in a high degree the spirit of patriotism, fidelity, obedience, courage, and sympathy, were always ready to give aid to each other and to sacrifice themselves for the common good, would be victorious over other tribes; and this would be natural selection."

Here, Darwin describes how group-level competition can produce authentic altruism. In The Social Conquest of the Earth, Wilson updates Darwin’s case, mainly drawing on his expertise as an entomologist. Wilson argues that the incredible levels of cooperation and altruism within ant colonies testify to millions of years of vicious conflict between colonies. Darwin and Wilson agree: no matter the species, if you have intense and sustained group-level conflict, selfless genes beat selfish genes; they beat them bloody; they beat them every single time.

Of course, it would be a great distortion to suggest that people are, like ants, selfless all of the time. But the vision of rigid selfishness that arose from biology’s rejection of group selection was an equally great distortion. The real picture is more complex. Natural selection occurs at the level of groups and individuals. Competition between groups favors selfless genes while competition inside groups favors selfish genes. As Wilson and a colleague wrote in a different publication, "Selfishness beats altruism within groups. Altruistic groups beat selfish groups. Everything else is commentary."

Jonathan Gottschall is the author of The Storytelling Animal: How Stories Make us Human.