The controversial origins of war and peace
– by Luke Glowacki
When I set out to write my recent article The Controversial Origins of War and Peace: Apes, Foragers, and Human Evolution, I hoped to provide clarity on the heated debate about the role of war and peace in human evolution. Is warfare part of our evolutionary legacy, or did it emerge from the societal shifts brought about by agriculture and permanent settlements? This isn’t just an academic puzzle—it’s a question that cuts to the core of how we understand ourselves, our past, and the future of human coexistence. My goal was to peel back the oversimplification that commonly characterizes both sides and dig into the messy, complex reality of our evolutionary journey.
The debate often falls into two camps: “deep rooters” and “shallow rooters.” Deep rooters argue that warfare has ancient roots, embedded deep in our evolutionary history, possibly stretching back to our last common ancestor with chimpanzees and bonobos. They point to the brutal, coordinated violence among chimpanzees as evidence that our lineage is steeped in conflict. Deep rooters take the fact that hunter-gatherers often have war as evidence that war would have occurred among our Pleistocene ancestors. Shallow rooters, on the other hand, see war as a recent human invention, a consequence of agriculture, sedentary life, and hierarchical societies. War emerged only recently they argue, once we stopped foraging and started living in settled agricultural communities. They highlight the peaceful, cooperative lives of bonobos and some hunter-gatherers, painting a picture of a more harmonious human past.
But here’s the rub, the debate has often overlooked that both war and intergroup cooperation are parts of our evolutionary legacy, and the evidence is not nearly as clearcut as both camps sometimes assume. Simplifying human evolution into a binary of “war” or “peace” misses the fascinating complexity of our story. Chimpanzees do engage in deadly raids but using them as a direct blueprint for early human behavior ignores millions of years of evolution that followed our split. And while bonobos are often held up as paragons of peace, their societies aren’t entirely free of aggression. While lethal raids have not been reported for bonobos, they do appear to have rates of aggression that can rival chimpanzees. And neither species may be useful for understanding the last common ancestor humans shared with other apes. Further, we’ve had seven million years of evolution since sharing a common ancestor with chimpanzees and bonobos, raising questions about how much of our behavior is really inherited from a last common ancestor.
When I turned to the archaeological and ethnographic records of hunter-gatherers, the picture is even more complex. It’s tempting to believe that warfare only appeared with the advent of agriculture, but that’s not what the evidence shows. Small-scale intergroup violence existed long before humans settled into farming communities, yet larger-scale violence appears to emerge only more recently. Just as often though, hunter-gatherers engaged in cooperative trade and alliances. And while many of them have war, war may be intermittent and even rare. Evidence of intergroup trade spanning hundreds of kilometers extends deep into the Paleolithic.
Our ancestors weren’t locked into one mode of interaction; they were adaptable, capable of both conflict and collaboration depending on the circumstances. And like humans everywhere, they likely used conflict and cooperation to obtain their goals depending on the circumstances. Because both cooperation and conflict have strong fitness relevance, both were likely important selective features in our species’ history.
What struck me—and what I hope strikes readers—is the dual legacy of war and peace in human evolution. Both violence and cooperation have been powerful forces shaping who we are. This duality resonates with the world we live in today, where acts of war and moments of profound cooperation coexist. We’re equipped for both, and it’s our environment, culture, and social structures that shapes which path we follow.
This understanding isn’t just intellectually satisfying—it’s hopeful. If peace is as much a part of our evolutionary toolkit as war, then striving for harmonious coexistence isn’t some naive dream; it’s a fundamental part of who we are. Recognizing this can shape how we approach conflict resolution and peacebuilding today. It reminds us that while conflict may be a part of our past, it is not an inevitable feature of our future.
Read the original article: Glowacki, L. (2024) The controversial Origins of war and peace: apes, foragers, and human evolution. Evolution & Human Behavior, 45(6), 106618.
