To End War, We Need To Understand Its Origins, Evolution And Causes

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Michael L. Wilson and Richard W. Wrangham in Monkey Business: In a recent opinion piece for Scientific American, John Horgan writes “Ending war won’t be easy, but it should be a moral imperative, as much so as ending slavery and the subjugation of women. The first step toward ending war is believing it is possible.” As part of his argument he declared that “far from having deep evolutionary roots, [war] is a relatively recent cultural invention”…

…Like any other sane individual aware of the power of nuclear weapons, we of course agree that is desirable to reduce major wars to zero. We consider this goal to be part of the “possibilist agenda” —  an approach that begins by ruling out what is impossible, given the laws of the universe, rather than pessimistically focusing on what results are most probable to occur.1  Is ending war possible? Well, we don’t know of any laws of physics, or even principles of evolutionary biology, that would make it impossible to end war. The task before us remains finding the best means to achieve this goal. This includes gaining a clear, scientific understanding of what war is, what its causes are, and what factors can prevent it.

…There are reasons for optimism. The examples Horgan cites shows that extended peace is a reasonable possibility, given that wars have been absent for decades in parts of the world. As Stephen Pinker described in exhaustive detail in his 2011 book, The Better Angels of Our Nature, deaths from international warfare declined steeply after 1945. Many of the richer countries that formerly engaged in long and bitter wars with one another — the United States, Japan, Germany, France, England — are currently closely allied in long-term friendships. The United States and Canada, for example, haven’t fought each other in earnest since the War of 1812, and as each other’s largest trading partners, benefit greatly from trading rather than invading…

…We also agree that much about war involves “relatively recent cultural inventions.” Certainly contemporary weapons are entirely different from those used by the hunter-gatherers of Nataruk, Kenya, 10,000 years ago to execute their enemies, or by the several hunter-gatherer societies of India’s remote Andaman Islands who lived in permanent war with each other. Equally novel are the hierarchies that give leaders power to order warriors into battle, and the military training that promotes efficient tactics, and ideologies that encourage self-sacrifice even to the point of suicide, and the assembly of huge armies. There are many such novelties. But so what? They cast no direct light on the question of the antiquity of war, or more importantly on the question of whether the possible practice of lethal intergroup aggression by our remote ancestors has left a legacy in the human psyche…

Illustration by Irshad Salim

…Whether war has deep evolutionary roots remains an unsettled topic, contrary to Horgan’s assertions. For example, Horgan links to his 2016 blog post, in which he describes a study led by Hisashi Nakao of skeletal trauma in hunter-gatherers living in Japan 12,000 to 2,800 years ago, which reports that only a small proportion of skeletons showed evidence of violent death. However, as noted in a 2020 review by Mark Hudson and colleagues, “[i]ndividual finds of arrowheads embedded in human bones and other similar, clear-cut traces of violence have long been known in Japan as elsewhere.” Although Nakao and colleagues consider their findings to represent a low rate of violence,  their sample includes cases of “blunt force injuries to the cranium and embedded stone and bone projectile points in the post-crania with no signs of healing – providing a prevalence of 1.8 per cent of adults dying violently.” 

…if we take the rate of 1.8% adult deaths from violence at face value, this is about 2.5 times the rate of death from homicide in the United States in 20202, a year marked by a dramatic increase in violence. What does this tell us about the evolutionary roots of war? It provides additional evidence that people in prehistory faced a threat of death from violence, but also provides additional evidence that rates of violence vary across space and time, for reasons that are worth exploring further.

…As an example of a fatalism that will lead to more war, Horgan offers this quotation from Kaja Kallas, the prime minister of Estonia: “Sometimes the best way to achieve peace is to be willing to use military strength.” People living in Estonia, however, have bitter historical experience with being invaded and occupied. If you live next door to Putin’s Russia, rather than Trudeau’s Canada, the best way to prepare for peace may indeed be to prepare for war. International peace will not be achieved by simply giving in. Peace among nations surely requires making the costs of war so high that when appeals to law or morality fail, potential aggressors recognize that it is in their own best interests to find a constructive solution.

More here.