Is human behavior controlled by our genes? Richard Levins reviews ‘The Social Conquest of Earth’

Introduction by Ian Angus

In 1975, in the bestselling book Sociobiology: The New Synthesis, Harvard biologist Edward O. Wilson argued that human traits such as aggression, racism and gender bias are controlled by our genes, the product of evolution. His theories were hailed by some as a breakthrough that explained human nature, and condemned by others for attributing social problems to biological causes.

In his latest book, The Social Conquest of Earth (Liverwright 2012), Wilson offers his current views on the connections between evolution, biology and society. He has changed his views on some subjects, notably kin selection, but he still argues, in his publisher’s words, that “the sources of morality, religion, and the creative arts are fundamentally biological in nature.”

I could think of no person more qualified to review this book than Dick Levins, co-author of two of my all-time favorite Marxist books on science, The Dialectical Biologist (Harvard University Press 1985) and Biology Under the Influence (Monthly Review 2007).

I’m pleased and honored that he agreed – his review, written specifically for Climate and Capitalism, is below.

Richard Levins is John Rock Professor of Population Sciences at the Harvard School of Public Health. In addition to academic journals, he writes frequently for the Marxist journal Monthly Review. His recent articles for MR include Continuing Sources of Marxism, and How to Visit a Socialist Country.

In 2001 he was awarded the 30th Anniversary Medal of the Cuban Academy of Sciences for his work on pest management and new diseases in Cuba. He was also given the title of research collaborator of the Ministry of Science, Technology, and the Environment.

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Edward O. Wilson. The Social Conquest of Earth. Liverwright Publishing, New York, 2012

reviewed by Richard Levins

In the 1970s, Edward O. Wilson, Richard Lewontin, Stephen Jay Gould and I were colleagues in Harvard’s new department of Organismic and Evolutionary Biology. In spite of our later divergences, I retain grateful memories of working in the field with Ed, turning over rocks, sharing beer, breaking open twigs, putting out bait (canned tuna fish) to attract the ants we were studying..

We were part of a group that hoped to jointly write and publish articles offering a common view of evolutionary science, but that collaboration was brief, largely because Lewontin and I strongly disagreed with Wilson’s Sociobiology.

Reductionism and Sociobiology

Although Wilson fought hard against the reduction of biology to the study of molecules, his holism stopped there. He came to promote the reduction of social and behavioral science to biology. In his view:

“Our lives are restrained by two laws of biology: all of life’s entities and processes are obedient to the laws of physics and chemistry; and all of life’s entities and processes have arisen through evolution and natural selection.” [Social Conquest, p. 287]

This is true as far as it goes but fails in two important ways.

First, it ignores the reciprocal feedback between levels. The biological creates the ensemble of molecules in the cell; the social alters the spectrum of molecules in the biosphere; biological activity creates the biosphere itself and the conditions for the maintenance of life.

Second, it doesn’t consider how the social level alters the biological: our biology is a socialized biology.

Higher (more inclusive) levels are indeed constrained by the laws at lower levels of organization, but they also have their own laws that emerge from the lower level yet are distinct and that also determine which chemical and physical entities are present in the organisms. In new contexts they operate differently.

Thus for example we, like a few other animals including bears, are omnivores. For some purposes such as comparing digestive systems that’s an adequate label. But we are omnivores of a special kind: we not only acquire food by predation, but we also produce food, turning the inedible into edible, the transitory into stored food. This has had such a profound effect on our lives that it is also legitimate to refer to us as something new, productivores.

The productivore mode of sustenance opens a whole new domain: the mode of production. Human societies have experienced different modes of production and ways to organize reproduction, each with its own dynamics, relations with the rest of nature, division into classes, and processes which restore or change it when it is disturbed.

The division of society into classes changes how natural selection works, who is exposed to what diseases, who eats and who doesn’t eat, who does the dishes, who must do physical work, how long we can expect to live. It is no longer possible to prescribe the direction of natural selection for the whole species.

So failing to take class division into account is not simply a political bias. It also distorts how we look at human evolution as intrinsically bio-social and human biology as socialized biology.

The opposite of the genetic determinism of sociobiology is not “the blank slate” view that claims that our biological natures were irrelevant to behavior and society. The question is, what about our animal heritage was relevant?

We all agree that we are animals; that as animals we need food; that we are terrestrial rather than aquatic animals; that we are mammals and therefore need a lot of food to support our high metabolic rates that maintain body temperature; that for part of our history we lived in trees and acquired characteristics adapted to that habitat, but came down from the trees with a dependence on vision, hands with padded fingers, and so on. We have big brains, with regions that have different major functions such as emotions, color vision, and language.

But beyond these general capacities, there is widespread disagreement about which behaviors or attitudes are expressions of brain structure. The amygdala is a locus of emotion, but does it tell us what to be angry or rejoice about? It is an ancient part of our brains, but has it not evolved in response to what the rest of the brain is doing? There is higher intellectual function in the cortex, but does it tell us what to think about?

Every part of an organism is the environment for the rest of the organism, setting the context for natural selection. In contrast to this fluid viewpoint, phrases such as “hard-wired” have become part of the pop vocabulary, applied promiscuously to all sorts of behaviors.

In a deeper sense, asking if something is heritable is a nonsense question. Heritability is always a comparison: how much of the difference between humans and chimps is heritable? What about the differences between ourselves and Neanderthals? Between nomads and farmers?

Social Conquest of Earth

The Social Conquest of Earth, Ed Wilson’s latest book, continues his interest in the “eusocial” animals – ants, bees and others that live in groups with overlapping generations and a division of labor that includes altruistic behavior. As the title shows. he also continues to use the terminology of conquest and domination, so that social animals “conquer” the earth, their abundance makes them “dominate.”

The problem that Wilson poses in this book is first, why did eusociality arise at all, and second, why is it so rare?

Wilson is at his best when discussing the more remote past, the origins of social behavior 220 million years ago for termites, 150 million years for ants, 70-80 million years for humble bees and honey bees.

But as he gets closer to humanity the reductionist biases that informed Sociobiology reassert themselves. Once again Wilson argues that brain architecture determines what people do socially – that war, aggression, morality, honor and hierarchy are part of “human nature.”

Rejecting kin selection

A major change, and one of the most satisfying parts of the book, is his rejection of kin selection as a motive force of social evolution, a theory he once defended strongly.

Kin selection assumed that natural selection acts on genes. A gene will be favored if it results in enhancing its own survival and reproduction, but it is not enough to look at the survival of the individual. If my brother and I each have 2 offspring, a shared gene would be doubled in the next generation. But if my brother sacrifices himself so that I might leave 5 offspring while he leaves none, our shared gene will increase 250%.

Therefore, argued the promoters of this theory, the fitness that natural selection increases has to be calculated over a whole set of kin, weighted by the closeness of their relationship. Mathematical formulations were developed to support this theory. Wilson found it attractive because it appeared to support sociobiology.

However, plausible inference is not enough to prove a theory. Empirical studies comparing different species or traits did not confirm the kin selection hypothesis, and a reexamination of its mathematical structure (such as the fuzziness of defining relatedness) showed that it could not account for the observed natural world. Wilson devotes a lot of space to refuting kin selection because of his previous support of it: it is a great example of scientific self-correction.

Does group selection explain social behaviour?

Wilson has now adopted another model in which the evolution of sociality is the result of opposing processes of ordinary individual selection acting within populations, and group selection acting between populations. He invokes this model account to for religion, morality, honor and other human behaviors.

He argues that individual selection promotes “selfishness” (that is, behavior that enhances individual survival) while group selection favors cooperative and “altruistic” behavior. The two forms of selection oppose each other, and that results in our mixed behaviors.

“We are an evolutionary chimera living on intelligence steered by the demands of animal instinct. This is the reason we are mindlessly dismantling the biosphere and with it, our own prospects for permanent existence.” [p.13]

But this simplistic reduction of environmental destruction to biology will not stand. Contrary to Wilson, the destruction of the biosphere is not “mindless.” It is the outcome of interactions in the noxious triad of greed, poverty, and ignorance, all produced by a socio-economic system that must expand to survive.

For Wilson, as for many environmentalists, the driver of ecological destruction is some generic “we,” who are all in the same boat. But since the emergence of classes after the adoption of agriculture some 8-10,000 years ago it is no longer appropriate to talk of a collective “we.”

The owners of the economy are willing to use up resources, pollute the environment, debase the quality of products, and undermine the health of the producers out of a kind of perverse economic rationality. They support their policies with theories such as climate change denial or doubting the toxicity of pesticides, and buttress it with legislation and court decisions.

Evolution and religion

The beginning and end of the book, a spirited critique of religion as possibly explaining human nature, is more straightforwardly materialist than the view supported by Stephen J. Gould, who argued that religion and science are separate magisteria that play equal roles in human wellbeing.

But Wilson’s use of evidence is selective.

For example, he argues that religion demands absolute belief from its followers – but this is true only of Christianity and Islam. Judaism lets you think what you want as long as you practice the prescribed rituals, Buddhism doesn’t care about deities or the afterlife.

Similarly he argues that creation myths are a product of evolution:

“Since paleolithic times … each tribe invented its own creation myths… No tribe could long survive without a creation myth… The creation myth is a Darwinian device for survival.” [p. 8]

But the ancient Israelites did not have an origin myth when they emerged as a people in the hills of Judea around 1250 B.C.E. Although it appears at the beginning of the Bible, the Israelites did not adapt the Book of Genesis from Babylonian mythology until four centuries after Deuteronomy was written, after they had survived 200 years as a tribal confederation, two kingdoms and the Assyrian and Babylonian conquests— by then the writing of scripture was a political act, not a “Darwinian device for survival.”

Biologizing war

In support of his biologizing of “traits,” Wilson reviews recent research that appears to a show a biological basis for the way people see and interpret color, for the incest taboo, and for the startle response – and then asserts that inherited traits include war, hierarchy, honor and such. Ignoring the role of social class, he views these as universal traits of human nature.

Consider war. Wilson claims that war reflects genes for group selection. “A soldier going into battle will benefit his country but he runs a higher risk of death than one who does not.” [p. 165]

But soldiers don’t initiate conflict. We know in our own times that those who decide to make war are not those who fight the wars – but, perhaps unfortunately, sterilizing the general staff of the Pentagon and of the CIA would not produce a more peaceful America.

The evidence against war as a biological imperative is strong. Willingness to fight is situational.

Group selection can’t explain why soldiers have to be coerced into fighting, why desertion is a major problem for generals and is severely punished, or why resistance to recruitment is a major problem of armies. In the present militarist USA, soldiers are driven to join up through unemployment and the promises of benefits such as learning skills and getting an education and self-improvement. No recruitment posters offer the opportunity to kill people as an inducement for signing up.

The high rates of surrender and desertion of Italian soldiers in World War II did not reflect any innate cowardice among Italians but a lack of fascist conviction. The very rarity of surrender by Japanese soldiers in the same war was not a testimony to greater bravery on the part of the Japanese but of the inculcated combination of nationalism and religion.

As the American people turned against the Vietnam war, increased desertions and the killing of officers by the soldiers reflected their rejection of the war.

The terrifying assaults of the Vikings during the middle ages bear no resemblance to the mellow Scandinavian culture of today, too short a time for natural selection to transform national character.

The attempt to make war an inherited trait favored by natural selection reflects the sexism that has been endemic in sociobiology. It assumes that local groups differed in their propensity for aggression and prowess in war. The victorious men carry off the women of the conquered settlements and incorporate them into their own communities. Therefore the new generation has been selected for greater military success among the men. But the women, coming from a defeated, weaker group, would bring with them their genes for lack of prowess, a selection for military weakness! Such a selection process would be self-negating.

Ethnocentrism

Wilson also considers ethnocentrism to be an inherited trait: group selection leads people to favor members of their own group and reject outsiders.

The problem is that the lines between groups vary under different circumstances. For example, in Spanish America, laws governing marriage included a large number of graded racial categories, while in North America there were usually just two. What’s more, the category definitions are far from permanent: at one time, the Irish were regarded as Black, and the whiteness of Jews was questioned.

Adoption, immigration, mergers of clans also confound any possible genetic basis for exclusion.

Hierarchy

Wilson draws on the work of Herbert Simon to argue that hierarchy is a result of human nature: there will always be rulers and ruled. His argument fails to distinguish between hierarchy and leadership.

There are other forms of organization possible besides hierarchy and chaos, including democratic control by the workers who elect the operational leadership. In some labor unions, leaders’ salaries are pegged to the median wage of the members. In University departments the chairmanship is often a rotating task that nobody really wants. When Argentine factory owners closed their plants during the recession, workers in fact seized control and ran them profitably despite police sieges.

Darwinian behavior?

Wilson argues that “social traits” evolved through Darwinian natural selection. Genes that promoted behaviors that helped the individual or group to survive were passed on; genes that weakened the individual or group were not. The tension between individual and group selection decided which traits would be part of our human nature.

But a plausible claim that a trait might be good for people is not enough to explain its origin and survival. A gene may become fixed in a population even if it is harmful, just by the random genetic changes that we know occur. Or a gene may be harmful but be dragged along by an advantageous gene close to it on the same chromosome.

Selection may act in different directions in different subpopulations, or in different habitats, or in differing environmental. Or the adaptive value of a gene may change with its prevalence or the distribution of ages in the population, itself a consequence of the environment and population heterogeneity.

For instance, Afro-Americans have a higher death rate from cancer than Euro-Americans. In part this reflects the carcinogenic environments they have been subjected to, but there is also a genetic factor. It is the combination of living conditions and genetics that causes higher mortality rates.

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Obviously I am not arguing that evolution doesn’t happen. The point is that we need a much better argument than just a claim that some genotype might be beneficial. And we need a much more rigorous understanding of the differences and linkages between the biological and social components of humanity’s nature. Just calling some social behavior a “trait” does not make it heritable.

In a book that attempts such a wide-ranging panorama of human evolution, there are bound to be errors. But the errors in The Social Conquest of Earth form a pattern: they reduce social issues to biology, and they insist on our evolutionary continuity with other animals while ignoring the radical discontinuity that made us productivores and divided us into classes.