Is warfare innate in humans? The remains of what appears as a brutal war of ancient hunter-gatherers – found near a Kenyan lake in Africa – may hold a clue to the elusive, much-debated matter.
Picture the scene of the ancient grave site: 10,000-year-old remains of 27 people, with some skulls crushed and others struck with arrows in the heads and necks. Even a pregnant woman's hands and feet were bound.
The Nataruk massacre finds, studied in research published in the journal Nature, might as well be the oldest proof of warfare taking place between humans.
The findings fuel the belief that human warfare, after all, might be as old as humans are, according to the University of Cambridge researchers.
"These human remains... provide unique evidence that warfare was part of the repertoire of inter-group relations among some prehistoric hunter-gatherers," explained study lead author Dr. Marta Mirazon Lahr in a statement.
She added that the Nataruk massacre may have rooted from attempts to seize resources, which operates on the same underlying principle of violent attacks on settlements in agricultural societies.
However, it is unclear whether the dwellers on the land around the lake at the time of the bloody encounter were already forming a society where violent clashes were fairly commonplace.
A separate study argued that a violent past may have a hand in the evolution of human faces, which it proposed was a result of the need to adapt to or survive punches during physical fights.
University of Utah biologist and co-author David Carrier said that the anatomical features that distinguish humans from other primates seemed to improve fighting ability – supporting the hypothesis that early ancestors were indeed aggressive.
"[M]any of the anatomical characters of great apes and our ancestors, the early hominins (such as bipedal posture, the proportions of our hands and the shape of our faces) do, in fact, improve fighting performance," Carrier explained.
Many philosophers and evolution experts long argued that violence and war indeed have deep roots in human biology - a theory championed by the likes of Thomas Hobbes yet countered by Jean-Jacques Rousseau, who said it was only civilization that corrupted humans and made us more violent.
Even U.S. President Barack Obama has weighed in on the matter, expressing in his 2009 Nobel Peace Prize acceptance speech that war "in one form or another, appeared with the first man."
The Nataruk massacre, however, seems to not offer an outright conclusion, only an enriching take on the discussion.
But for co-author and Cambridge professor Robert Foley, aggressive and lethal tendencies could be embedded in human DNA as much as being "deeply caring and loving" is.