The Spoils of War
Margaret Power’s questions cut to the heart of the matter: why fight if there’s nothing worth fighting over? Before the scientists started provisioning the apes, food appeared throughout the jungle, so the chimps spread out in search of something to eat each day. Chimps often call out to the others when they find a fruiting tree; mutual aid helps everyone, and feeding in the forest isn’t a zero-sum endeavor. But once they learned that there would be a limited amount of easy food available in the same place each day, more and more chimps started arriving in aggressive, “noisy hordes” and “hanging around.” Soon after, Goodall and her students began witnessing the now-famous “warfare” between chimp groups.
Perhaps for the first time ever, the chimps had something worth fighting over: a concentrated, reliable, yet limited source of food. Suddenly, they lived in a zero-sum world.
Applying this same reasoning to human societies, we’re left wondering why immediate-return hunter-gatherers would risk their lives to fight wars. Over what, exactly? Food? That’s spread out in the environment. Societies indigenous to areas where food is concentrated by natural conditions, like the periodic salmon runs of the Pacific Northwest of the United States and Canada, tend not to be immediate-return hunter-gatherers. We’re more likely to find complex, hierarchical societies like the Kwakiutl (discussed later) in such spots. Possessions? Foragers have few possessions of any nonsentimental value. Land? Our ancestors evolved on a planet nearly empty of human beings for the vast majority of our existence as a species. Women? Possibly, but this claim presumes that population growth was important to foragers and that women were commodities to be fought over and traded like the livestock of pastoralists. It’s likely that keeping population stable was more important to foragers than expanding it. As we’ve seen, when a group reaches a certain number of people, it tends to split into smaller groups anyway, and there is no inherent advantage in having more people to feed in band-level societies. We’ve also seen that women and men would have been free to move among different bands in the fission-fusion social system typical of hunter-gatherers, chimps, and bonobos.
The causal reverberations between social structure (foraging, horticultural, agrarian, industrial), population density, and the likelihood of war is supported by research conducted by sociologist Patrick Nolan, who found, “Warfare is more likely in advanced horticultural and agrarian societies than it is in hunting-and-gathering and simple horticultural societies.” When he limited his analysis only to hunter-gatherer and agrarian societies, Nolan found that above-average population density was the best predictor of war.21
This finding is problematic for the argument that human war is a “5-million-year habit,” given our ancestors’ low population densities until the post-agricultural population explosion began just a few thousand years ago. Recent research looking at changes in mitochondrial DNA confirms that already low prehistoric global human population levels dropped nearly to extinction at several points (due to climatological catastrophes probably triggered by volcanic eruptions, asteroid strikes, and sudden changes in ocean currents). As mentioned previously, the entire world population of Homo sapiens may have dropped to just a few thousand individuals as recently as 74,000 years ago, when the massive Toba eruption severely disrupted world climate. But even with much of the northern hemisphere covered in ice, the world was anything but crowded for our distant ancestors.22
Population demographics have triggered wars in more recent historical times. Ecologist Peter Turchin and anthropologist Andrey Korotayev looked at data from English, Chinese, and Roman history, finding strong statistical correlations between increases in population density and warfare. Their research suggests population growth could account for as much as 90 percent of the variation between historical periods of war and peace.23
Early agriculture’s stores of harvested grain and herds of placid livestock were like boxes of bananas in the jungle. There was now something worth fighting over: more. More land to cultivate. More women to increase population to work the land, raise armies to defend it, and help with the harvest. More slaves for the hard labor of planting, harvesting, and fighting. Failed crops in one area would lead desperate farmers to raid neighbors, who would retaliate, and so on, over and over.24
Freedom (from war) is just another word for nothing to lose—or gain.
But neo-Hobbesians ignore this rather straightforward analysis and the data supporting it, insisting that war must be an eternal human drive, all too often resorting to desperate rhetorical tactics like Pinker’s to defend their view.
In the fourth chapter of his book Sick Societies: Challenging the Myth of Primitive Harmony, for example, Robert Edgerton writes, “Social stratification developed in some small-scale societies that lacked not only bureaucracies and priesthoods but cultivation as well.” Okay, but in support of this assertion about social stratification and brutal rule by elites in “small-scale societies,” he offers fifteen pages of vivid descriptions of, in this order (and leaving nothing out):
• the Kwakiutl Indians of Vancouver Island (a slave-owning, settled, property-accumulating, potlatch-celebrating, complex, hierarchical society);
• the Aztec Empire (numbering in the millions, with elaborate religious structures, priesthoods, and untold acres of slave-cultivated land around a capital city larger than any in Europe at the time of first contact, featuring sewage systems and lighted streets at night);
• the Zulu Empire (again, numbering well into the millions, with slavery, intensive agriculture, animal domestication, and continent-wide trade networks);
• the Asante Empire of present-day Ghana, which, Edgerton tells us, “was incomparably the greatest military power in West Africa.”25
What any of these empires have to do with small-scale societies with no bureaucracies, priesthoods, or cultivation, Edgerton doesn’t say. In fact, he doesn’t mention a single foraging society for the rest of the chapter. This is like declaring that cats are difficult to train, then offering as evidence German shepherds, beagles, greyhounds, and golden retrievers.
In Beyond War, anthropologist Doug Fry rebuts the neo-Hobbesian view of universal war. “The belief that ‘there has always been war,’” Fry writes, “does not correspond with the archaeological facts of the matter.” Anthropologist Leslie Sponsel agrees, writing, “Lack of archaeological evidence for warfare suggests that it was rare or absent for most of human prehistory.” After conducting a comprehensive review of prehistoric skeletal evidence, anthropologist Brian Ferguson concluded that apart from one particular site in modern-day Sudan, “only about a dozen Homo sapiens skeletons 10,000 years old or older, out of hundreds of similar antiquity examined to date, show clear indications of interpersonal violence.” Ferguson continues, “If warfare were prevalent in early prehistoric times, the abundant materials in the archaeological record would be rich with evidence of warfare. But the signs are not there.”26
Our bullshit detectors go off when scholars point to violent chimps and a few cherry-picked horticultural human societies mislabeled as foragers, claiming these as evidence of ancient tendencies toward warfare. Even more troubling, these scholars often remain mute on the distorting effects on chimps of food provisioning, ever-shrinking habitats under siege from armies of hungry soldiers and poachers, reduced living space, food, and genetic vigor. Equally troubling is their silence on the crucial effects of population demographics and the rise of the agricultural state on the likelihood of human conflict.