Luc De Keyser ponders this searching question in the light of our scientific knowledge and preconceived ideas.

In May, Barack Obama became the first sitting US President to visit Hiroshima. The move left political analysts combing his speech for clues as to whether Washington’s foreign policy was changing. Anthropologists, on the other hand, looked for something different.

In commemorating one of the most devastating acts of war the world has ever seen, Obama couldn’t help but examine his basic beliefs about war itself. In his speech he explained that war grows ‘out of the same base instinct for domination or conquest that had caused conflicts among the simplest tribes’. He also argued, however, that mankind can choose to make peace its destiny because ‘we’re not bound by genetic code to repeat the mistakes of the past’. But is he right?

Before tackling the question of whether waging war is inherent to man’s nature, we must first recognise that our conclusions will be influenced by the preconceptions we have already formed. In reading the question, I venture to guess that most readers have already thought about their own answer. Some of you probably said, ‘yes, of course’; others may have answered ‘certainly not.’ Still others may fall somewhere in between, convinced, like Obama, that man has a biological instinct for war that he can choose not to act upon. All the while, psychologists would say that even if you have decided to read on, you will be motivated to cherry-pick support for your intuitive response. Instead, I urge you to keep an open mind to arguments based on reason, arguments that by necessity must begin by analysing what the terms and concepts within this question mean to different people in different contexts.

Some people may be convinced that man has a biological instinct for war that he can choose not to act upon
LEST WE FORGET: In May, Barack Obama commemorated one of the world’s most horrific acts of war
LEST WE FORGET: In May, Barack Obama commemorated one of the world’s most horrific acts of war

The saying goes, ‘Asking the right question is half the answer’. How, then, can we rephrase the question to make it right? Today, there are at least a dozen secular theories of why man wages war, framed within fields from economics and philosophy to sociology, psychology and anthropology. But the original question explicitly deals in human nature. If we accept that man’s biology makes sense only within the context of evolution, then that is where we must start.

Evolution traces the path of organisms whose traits are expressed by genes that strive to propagate themselves. Though Darwin’s theory aimed to explain how this works, many misconceptions about evolution still exist. Because some of them continue to confuse the discussion about the heredity of war, we should review them before we go any further.


Nature versus nurture

The human brain prefers to make easy choices: Is war in our genes, or is it something we learn? If the world were that simple, our course of action moving forward would be, too. If war were genetic, it would make sense to conclude that it would stay with man forever, and we had better be prepared for battle. If war were learned, then we could eliminate it by reshaping our culture toward peace.

But this interpretation of the classic ‘nature versus nurture’ debate loses its original meaning. The term refers only to the differences that changes in nature or nurture can actually make. Consider the act of baking bread. It makes no sense to ask which is more important, the dough or the oven? Both are essential to producing bread, and neither could achieve much on its own. It does, however, make sense to ask whether differences in browning are due more to variations in oven temperature or in the recipe. A more accurate way to think about this concept, then, might be to rebrand it as ‘nature and nurture’.


Scientists attempting to study the relative importance of nature and nurture in human behaviour must look at cases involving identical twins (the same ‘dough’) who were adopted by different families (different ‘ovens’). For aggression, in particular, studies have shown that about half the variance in aggressive behaviour can be explained by genetics, while the other half stems from the environment. Put simply, science suggests that adjusting our environment, including our culture, could have some impact on man’s aggression but would not determine it completely.

Survival of the fittest

The wording of this concept is perhaps the most misleading of evolutionary theory, especially when applying it to the origins of war. ‘Survival’, in this use, does not refer to the individual but to genes’ capacity to replicate and endure. In that sense, individuals need only survive long enough to produce viable offspring. Furthermore, ‘fittest’ is not meant to denote the strongest or healthiest. Instead it indicates organisms that best fit the conditions they live in, meaning their genes have the greatest chance of replicating – a status that, once achieved, may or may not last. David Katz, the director of Yale University’s Prevention Research Center, put it brilliantly: A tribe of paper people might feel superior for overcoming a tribe of rock people, but only until it is defeated by a tribe of scissors people.

From a historical perspective, one might assume that kings and chieftains (or more broadly, conquering societies) have had the most opportunity to pass down their genes. But in reality it is far more complicated. Rulers often had offspring with the vanquished and were, in turn, wiped out by victorious enemies. Told through the lens of ‘survival of the fittest’, the story of the world’s winners and losers is one of genes, not of the individuals who carried them. Waging war, then, is not necessarily a natural expression of the ‘survival of the fittest’ concept.

The ascent of man

The title of one of Darwin’s seminal works begins with The Descent of Man. Yet we cannot help but look back at our history and feel as though our position in the world is ever improving. Man’s prehistoric path brought him to the top of the evolutionary tree. And since the agricultural revolution, man’s technology has spread across the globe and beyond, into space. As long as we consider this conquering of nature as the height of progress –and wars essential to reaching that height –it makes sense to assume that waging war is simply a ‘natural’ part of man’s ascent.

From an evolutionary perspective, though, the top of the evolutionary tree is a vast canopy that includes at least 1.5 million (and possibly as many as 100 million) species, only one of which is Homo sapiens. In theory, any of these species could use its distinguishing traits to make a similar claim to superiority. The snail would praise its unique and slimy mode of movement, the peacock the splendour of its tail, or the giraffe the length of its neck, just as man praises the complexity of his brain.

Of course, mankind is the species with the biggest impact on the modern world, so much so that this era could rightly be called the Anthropocene – the epoch of man. Even so, geologically speaking we are just a tiny footnote in Earth’s lengthy history; how could we ever compete with oceanic cyanobacteria, which have generated the oxygen in the atmosphere for billions of years, enabling oxygen-breathing beings like us to evolve? And though historical statistics seem to suggest that wars have been instrumental to pacifying various cultures in certain ages, there is no guarantee this phenomenon will continue to hold true for centuries to come.

The selfish gene

Much to the chagrin of its author, Richard Dawkins, The Selfish Gene has been widely misunderstood since it was published in 1976. Dawkins argued that genes are selfish in the sense that their goal is to proliferate, competing with other genes to do so. But popular perception has distorted his findings; many people have taken his book to mean that selfishness is genetically hardwired into man and thus suggest there is ‘a moral and ideological justification for selfishness to be adopted by modern human societies’. Based on that flawed logic, war would be an organised expression of the inherent selfishness that man cannot help but to act on.

The war gene?

In this era of genomic revolution, it is tempting to look for a link between all human behaviours and our chromosomes. But war is certainly too broad a concept to break down into a consistent set of behavioural traits. Even its constituent parts – aggression, competitiveness and the like – cannot be traced to a single gene but at best to an intricate cluster of genes that interact with one another. Because of that complex interaction, any trail from genetics to war mongering rapidly runs cold.

Reconstructing the origins of war

Together, these concepts show that asking whether it is natural for man to wage war makes little scientific sense. They also suggest that answers such as those Obama offered – that man has an inherent instinct to dominate or that man can escape his biological fate – are not supported by our current understanding of evolution. Instead, the question can be better understood as a moral query in

Since the agricultural revolution, human technology has spread across the globe and beyond, into space
Since the agricultural revolution, human technology has spread across the globe and beyond, into space

disguise: Is it acceptable for man to wage war? Evidently, the many possible answers lay outside the scope of science. But as we clear the faulty scientific assumptions away, I leave you with a fresh analogy in their place.

In their natural habitat, cats, big and small, are generally solitary hunters that fiercely defend their hunting grounds against the incursion of other cats. (Lions are the notable exception, since they often hunt in packs.) Surprisingly enough, domesticated cats have retained these instincts. But living in close quarters with humans, an abundance of easily obtainable food has subdued their innate aggression toward one another, enough to enable them to roam alleyways in hordes.

Likewise, in Paleolithic times humans were able to roam in small bands of hunter-gatherers –that is, as long as there were enough resources to go around. Bands would revert to marking and defending their territory against their rivals only when their delicate ecological balance was upset. The intensity of the resulting conflict was determined by the degree of imbalance at the time. With the advent of agriculture, a surplus of food spurred massive population growth, increasing the risk and impact of occasional famines. Periods of scarcity sent large groups of people in search of food, and they would keep moving as long as they were strong enough to raid other groups’ food stores.

The source of modern warfare, however, has been complicated by a characteristic that is unique to mankind. In addition to the physiological sense of not having enough, we have a psychological sense of not having our fair share. The latter has been the trigger for many of the world’s recent civil and international wars. Perhaps if we can learn to guard against such feelings we could further ‘domesticate’ ourselves to some degree. Even then, though, our success would largely be determined by whether the relevant genes prove malleable enough to make a difference. Unfortunately, no amount of resolve or willpower can change that fact.

Clearly, this is not a rallying cry that presidents can lean on in their speeches abroad. But perhaps they could start by steering away from divisive questions that have no basis in science and focus on those that do.

Dr Luc De Keyser currently serves as the chief medical information officer at Xperthis, the largest provider of hospital information systems solutions in Belgium. He has done pioneering work in multicentre clinical trials, medical ontologies, paleonutrition and examining human conflict from an evolutionary perspective.


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