Hobbes is hot. The 17th-century British philosopher argued that before civilization, our ancestors were mired in a “war of all against all.” Only the emergence of powerful governments, “Leviathans,” Hobbes called them, curbed our violent tendencies.
Many influential modern scholars espouse versions of this Hobbesian view. They include Richard Wrangham, Jared Diamond, Edward Wilson, Azar Gat, Steven LeBlanc, Lawrence Keeley and Steven Pinker.
In his 2011 bestseller The Better Angels of Our Nature, Pinker asserts that even the most war-torn modern states are “far less violent than traditional bands and tribes.” “Hobbes got it right,” Pinker declared in a 2007 essay.
The Hobbesian view overlaps with what I call the deep-roots theory of war, which holds that lethal group violence is innate, bred into us by natural selection. I tirelessly critique these claims [see Further Reading], because they have consequences. Many people believe that if war is innate, it is inevitable, and hence efforts to eradicate it are futile. [See Addendum.]
A new study in Nature, “The phylogenetic roots of human lethal violence,” adds fuel to the debate over the origins of violence. The study, carried out by Jose Maria Gomez of the University of Granada and three other researchers, asserts that “lethal violence is deeply rooted in the primate lineage” and that humans “inherited their propensity for violence.”
In a commentary in Nature, biologist Mark Pagel claims that the Gomez study represents a “serious blow” in favor of the Hobbesian viewpoint. Actually, the study of Gomez et al. contradicts Hobbesian/deep-roots models, which depict lethal violence as a genetic disease that civilization has helped to cure.
Gomez and his colleagues compiled estimates of rates of lethal violence observed within more than 1,000 mammalian species, including our own. The group found similar rates of intra-species violence among closely related species. Rates tended to be higher among social, territorial species, notably primates.
The group calculates that Homo sapiens, based on its genetic proximity to chimpanzees and other species, should have a mortality rate from intra-species violence of about two percent. That means violence causes two out of every hundred deaths.
Empirical data on violent deaths among Paleolithic humans—before the advent of agriculture and permanent settlements—also indicate that two percent died violently, according to Gomez et al. This convergence leads the researchers to conclude that human violence is at least partly genetic.
A caveat is in order: The study lumps together all forms of violence, from infanticide and executions to war between states. So its conclusions do not necessarily support the claim of the aforementioned scholars that war is innate. Just because aggression is innate does not mean war is.
But even disregarding this concern, the Gomez study does not support the Hobbesian hypothesis. Hobbesians cite rates of violent death among prehistoric humans ranging from 15 percent (Pinker) to 25 percent (LeBlanc), roughly an order of magnitude higher than the two-percent estimate of Gomez et al.
Noting how much lower their estimates are than those of Pinker and others, the Gomez team explains that “we have included more populations in our study and weighted all the analyses by the number of individuals per sample.” In other words, the Gomez estimates are more thorough.
Gomez’s group also shows lethal violence surging rather than declining for thousands of years after humans settled down and formed chiefdoms, states and empires. “The level of lethal violence during most historic periods was higher,” Gomez et al. write, than the level calculated for prehistoric humans. According to their data, lethal violence started declining worldwide about 500 years ago and fell below Paleolithic levels during the last 100 years.
Unlike Pagel, author of the commentary on their study, Gomez and his colleagues are cautious in drawing conclusions, and they emphasize the uncertainties in estimates of rates of ancient bloodshed. But they strike a Hobbesian note when commenting on the recent decline in global violence. “It is widely acknowledged,” they write, “that monopolization of the legitimate use of violence by the state significantly decreases violence in state societies.”
States, at their best, do indeed promote peace both within and beyond their borders. But during the last 100 years states have also been responsible for horrific warfare and genocide—and the invention of weapons that can destroy civilization. This detailed Wikipedia page estimates that during World War II, Germany lost 8 percent of its population, the Soviet Union 13 percent and Poland 17 percent.
States represent the solution to violence, but they are also part of the problem.
Addendum: None of the deep-roots proponents I mentioned above--Richard Wrangham, Jared Diamond, Edward Wilson, Azar Gat, Steven LeBlanc, Lawrence Keeley and Steven Pinker—has said that if war is innate it is inevitable. But others, including American military leaders, have expressed this fatalistic conclusion.
Postscript: In an upcoming column, I will post comments on the Gomez study by scholars specializing in the roots of violence.