by Frans de Waal
[Film by The Department of Expansion.]
For many years, anthropologists and biologists have been comparing the aggression of animals with human warfare. It started with Konrad Lorenz in the 1960s, and remains a popular endeavor. We have an aggressive instinct that leads to warfare, hence war will always be with us. This message was a bit hard to accept from Lorenz, an Austrian who served in the German army during WWII, but the debate continues as seen in the video above featuring interviews with Steven Pinker, Richard Wrangham, and myself.
Part of the problem is that modern warfare seems to have little to do with the raw aggressive instinct. Modern warfare rests on a tight hierarchical structure of many parties, not all of which are driven by aggression. In fact, most are just following orders. The decision to go to war is typically made by older men in the capital. When I look at a marching army, I don’t see aggression in action. I see the herd instinct: thousands of men in lock-step, willing to obey superiors.
In recent history, we have seen so much war-related death that we imagine that it must always have been like this, that warfare is written into our DNA. In the words of Winston Churchill: “The story of the human race is War. Except for brief and precarious interludes, there has never been peace in the world; and before history began, murderous strife was universal and unending.” But is Churchill’s warmongering state-of-nature any more plausible than Rousseau’s noble savage? Although archeological signs of individual murder go back hundreds of thousands of years, we lack similar evidence for warfare (such as graveyards with weapons embedded in a large number of skeletons) from before the agricultural revolution. Even the walls of Jericho — considered one of the first pieces of evidence of warfare and famous for having come tumbling down in the Old Testament — may have served mainly as protection against mudflows.
Long before this, our ancestors lived on a thinly populated planet, with altogether only a couple of million people. Before this, about 70,000 years ago, our lineage was at the edge of extinction living in scattered small bands. A study of mitochondrial DNA by genographer Doron Behar suggests: “Tiny bands of early humans developed in isolation from each other for as much as half of our entire history as a species.” These are hardly the sort of conditions to promote continuous warfare. My guess is that for our ancestors war was always a possibility, but that they followed the pattern of present-day hunter-gatherers, who do exactly the opposite of what Churchill surmised: they alternate long stretches of peace and harmony with brief interludes of violent confrontation.
Comparisons with apes hardly resolve this issue. Since it has been found that chimpanzees sometimes raid their neighbors and take their enemies’ lives, these apes have edged closer to the warrior image that we have of ourselves. Like us, chimps wage violent battles over territory. Genetically speaking, however, our species is exactly equally close to another ape, the bonobo, which does nothing of the kind. Bonobos can be unfriendly to their neighbors, but soon after a confrontation has begun, females often rush to the other side to have sex with both males and other females. Since it is hard to have sex and wage war at the same time, the scene rapidly turns into a peaceful gathering. Lethal aggression among bonobos has been unheard of.
The recent discovery of “Ardi” has added to the debate. Considered close to the last common ancestor of apes and humans, Ardipithecus ramidus had a less protruding mouth equipped with considerably smaller, blunter canine teeth than the chimpanzee's impressive fangs, which serve as deadly knives, capable of slashing open an enemy's face and skin. The aggressiveness of chimpanzees obviously loses some of its significance if our ancestors were built quite differently. What if chimps are outliers in an otherwise relatively peaceful lineage?
I don't think these issues are resolved, but I do attach importance to the frequency of PTSD among soldiers. In the video interview, Wrangham argues that the only reason PTSD occurs is because soldiers feel bad about an act that they actually enjoyed committing, but isn't guilt an awfully cognitive emotion compared to the depth of despair, the intense fear, the inner darkness experienced by veterans? If it were just guilt, we could probably talk them out of it. If Wrangham were right, one would expect that after a strongly supported war (such as the so-called “good” war) there would be much less PTSD than after an unnecessary war, such as the one in Iraq. I have never heard of such differences, though.
Killing or hurting others is something we find so horrendous, that wars are often a collective conspiracy to miss, an artifice of incompetence, a game of posturing rather than an actual hostile confrontation. I suggest everyone to read On Killing by U. S. Lieutenant Colonel Dave Grossman. Killing at close range has no glory, no pleasure, and is something the typical soldier tries to avoid at all cost. Only a tiny percentage of men does the vast majority of killing during a war. Most soldiers report a deep revulsion: they vomit at the sight of dead enemies, and end up with haunting memories. Life-long combat trauma was already known to the ancient Greeks as reflected in Sophocles' plays about the “divine madness” that led to Ajax's depression after the Trojan War and his subsequent suicide.
Why would a Greek hero, trained to fight and be proud of it, have second thoughts? It makes no sense unless we assume that humans are in fact not designed to kill humans, and that those who do and feel good about it are the exception.