Wars past, present, future
Humans and chimpanzees are intensely territorial. That is the apparent population control hardwired into their social systems. What the events were that occurred in the origin of the chimpanzee and human lines—before the chimpanzee-human split of 6 million years ago—can only be speculated. I believe that the evidence best fits the following sequence. The original limiting factor, which intensified with the introduction of group hunting for animal protein, was food. Territorial behavior evolved as a device to sequester the food supply. Expansive wars and annexation resulted in enlarged territories and favored genes that prescribe group cohesion, networking, and the formation of alliances.
For hundreds of millennia, the territorial imperative gave stability to the small, scattered communities of Homo sapiens, just as they do today in the small, scattered populations of surviving hunter-gatherers. During this long period, randomly spaced extremes in the environment alternately increased and decreased the population size so that it could be contained within territories. These demographic shocks led to forced emigration or aggressive expansion of territory size by conquest, or both together. They also raised the value of forming alliances outside of kin-based networks in order to subdue other neighboring groups.
Ten thousand years ago, at the dawn of the Neolithic era, the agricultural revolution began to yield vastly larger amounts of food from cultivated crops and livestock, allowing rapid growth in human populations. But that advance did not change human nature. People simply increased their numbers as fast as the rich new resources allowed. As food again inevitably became the limiting factor, they obeyed the territorial imperative. Their descendants have never changed. At the present time, we are still fundamentally the same as our hunter-gatherer ancestors, but with more food and larger territories. Region by region, recent studies show, the populations have approached a limit set by the supply of food and water. And so it has always been for every tribe, except for the brief periods after new lands were discovered and their indigenous inhabitants displaced or killed.
The struggle to control vital resources continues globally, and it is growing worse. The problem arose because humanity failed to seize the great opportunity given it at the dawn of the Neolithic era. It might then have halted population growth below the constraining minimum limit. As a species we did the opposite, however. There was no way for us to foresee the consequences of our initial success. We simply took what was given us and continued to multiply and consume in blind obedience to instincts inherited from our humbler, more brutally constrained Paleolithic ancestors.
Also see John Horgan's response to this piece, “No, War Is Not Inevitable.”
Excerpted from The Social Conquest of Earth
by Edward O. Wilson, published in April by
Liveright Publishing Corporation, a division of
W. W. Norton & Company, Inc. Copyright © 2012.
Fatality rate due to conflict
The last century has been called the Century of Total War: World Wars I and II, the Korean War, the Vietnam War, and other conflicts took an estimated 187 million human lives. But after analyzing archaeological and ethnographic data, social scientist Samuel Bowles of the Santa Fe Institute in New Mexico has reported even worse fatalities in hunter-gatherer societies stretching back at least 10,000 years and continuing to the present. War appeared to serve a purpose, culling population whenever numbers rose too high. Counterintuitively, war might have also fostered altruism: Since winning battles required cooperation, wartime mortality might have aided the evolution of an altruistic human nature through the process of natural selection.
7% Southern Sweden
Remains by an ancient lagoon called Skateholm indicate a 7% adult mortality rate due to warfare 6,100 years ago.
21% Southern Ukraine
Analysis of Vasiliv’ka III, an 11,000-year-old burial site, shows that 21% of adults died as a result of warfare. Another site, Volos’ke, shows evidence of a 22% adult mortality rate due to warfare.
30% Northern India
At Sarai Nahar Rai, a site inhabited by hunter-gatherers between 3,140 and 2,860 years ago, war caused 30% of adult deaths.
46% Northern Sudan
14,000 to 12,000 years ago, 46% of Nubian adults died in war.
21% Northeastern Australia
Among the Murngin, a group of maritime foragers, war accounted for about 21% of adult deaths between 1910 and 1930.
23% British Columbia
Across 30 sites dating to between 5,500 and 340 years ago, 23% of all adults died in war.
6% Southern California
Across 28 hunter-gatherer sites, warfare led to 6% of adult deaths between 5,500 and 630 years ago.
17% Venezuela-Colombia border
Before first contact in 1960, warfare caused 17% of adult deaths among the Hiwi, who were foragers.
30% Eastern Paraguay
Ethnographic evidence implies that war caused 30% of the deaths among hunter-gatherers here prior to Western contact in 1970.