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Survey of Earliest Human Settlements Undermines Claim That War Has Deep Evolutionary Roots

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My last two posts discuss two new studies that contradict the Deep Roots Theory of War, which holds that war is ancient and innate. One study concludes that modern-day mobile foragers (also called nomadic hunter gatherers) are far less warlike than Deep Rooters contend. According to the other study, there is vanishingly little archaeological evidence of lethal group violence prior to 10,000 years ago.

Ancient settlement in Jordan, Southern Levant, where humans lived without significant warfare from 15,000 to 5,500 years ago, according to new archaeological survey.

Both of these reports support the view of anthropologist Margaret Mead that war, rather than being a “biological necessity,” is a recent cultural innovation, or “invention.” Now I’d like to present results from a new archaeological survey that further corroborates Mead’s view of warfare.

The survey is by Rutgers anthropologist Brian Ferguson, an authority on the origins of warfare. In a 2003 Natural History article, “The Birth of War,” Ferguson presented preliminary results of his examination of early human settlements. He argued that “the global archaeological record contradicts the idea that war was always a feature of human existence; instead, the record shows that warfare is largely a development of the last 10,000 years.”

That conclusion has been corroborated by Ferguson’s new, in-depth survey, which he discusses in “The Prehistory of War and Peace in Europe and the Near East,” a chapter in War, Peace, and Human Nature, a 2013 collection edited by Douglas Fry and published by Oxford University Press. (See also a chapter in which Ferguson critiques an interpretation of archaeological data by Deep Rooter Steven Pinker.)

Ferguson closely examines excavations of early human settlements in Europe and the Near East in the Neolithic era, when our ancestors started abandoning their nomadic ways and domesticating plants and animals. Ferguson shows that evidence of war in this era is quite variable.

In many regions of Europe, Neolithic settlements existed for 500-1,000 years without leaving signs of warfare. “As time goes on, more war signs are fixed in all potential lines of evidence—skeletons, settlements, weapons and sometimes art,” Ferguson writes. “But there is no simple line of increase.”

By the time Europeans started supplementing stone tools with metal ones roughly 5,500 years ago, “a culture of war was in place across all of Europe,” Ferguson writes. “After that,” Ferguson told me by email, “you see the growth of cultural militarism, culminating in the warrior societies of the Bronze Age.”

Ferguson finds even more variability in the Near East. He notes that “the Western world’s first widespread, enduring social system of war” emerged almost 8,000 years ago in Anatolia, which overlaps modern-day Turkey and includes the legendary city of Troy. “This is the start of a system of war that flows down in a river of blood to the present,” Ferguson asserts.

But excavations in the Southern Levant–a region that includes modern Jordan, Syria, Israel and Palestine–tell a dramatically different story. Ferguson notes that hunter gatherers started settling in the Southern Levant 15,000 years ago, and populations surged after the emergence of agriculture there 11,000 years ago. But there is no significant evidence of warfare in the Southern Levant until about 5,500 years ago, when the region increasingly came under the influence of the emerging military empire of Egypt, according to Ferguson.

In other words, humans lived and thrived in the Southern Levant for roughly 10,000 years–a period that included population growth, climate shifts and environmental degradation, all of which are thought to be triggers of warfare—without waging war.

Ferguson notes that this conclusion is far from definitive; new excavations may reveal evidence of group violence in the Southern Levant. His research nonetheless contradicts simplistic arguments that war is the inevitable result of competition for resources or innate male aggression.

“War is very, very old,” Ferguson told me by email. “But we can still see its beginnings, and there is no basis for concluding that a) humans have always fought because we are innately inclined to it, or b) that war could act as a selection mechanism over evolutionary time.”

Postscript: In a new report in Science, researchers claim to have found “strong causal evidence linking climatic events to human conflict across a range of spatial and temporal scales and across all major regions of the world.” But as reported by Keith Kloor on his blog and Lauren Morello in Scientific American, other researchers are treating the report skeptically, as they should. The Science report counts baseball pitchers hitting batters as conflict, according to Morello. She notes, moreover, that Halvard Buhaug, a political scientist at the Peace Research Institute Oslo in Norway, believes that “the climate–conflict link is weak and inconsistent.” See also my related columns: “Are We Doomed to Wage Wars Over Water?,” “Why Bill McKibben’s Global Warming Fear Mongering Isn’t Helpful,” and “Margaret  Mead’s war theory kicks butt of Darwinian and neo-Malthusian models.” I understand why many greens and lefties are attracted to the notion that global warming may lead to war. But the evidence for this thesis is weak, and uncritical acceptance of it may lead not to a phase-out of fossil fuels but to a bigger military budget.

Photo by A. Sobkowski, courtesy Wikimedia Commons.

John Horgan About the Author: Every week, hockey-playing science writer John Horgan takes a puckish, provocative look at breaking science. A teacher at Stevens Institute of Technology, Horgan is the author of four books, including The End of Science (Addison Wesley, 1996) and The End of War (McSweeney's, 2012). Follow on Twitter @Horganism.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. Jack Strocchi 9:37 am 08/2/2013


    My last two posts discuss two new studies that contradict the Deep Roots Theory of War, which holds that war is ancient and innate. One study concludes that modern-day mobile foragers (also called nomadic hunter gatherers) are far less warlike than Deep Rooters contend. According to the other study, there is vanishingly little archaeological evidence of lethal group violence prior to 10,000 years ago. Both of these reports support the view of anthropologist Margaret Mead that war, rather than being a “biological necessity,” is a recent cultural innovation, or “invention.”

    Mr Horgan launches yet another Quixotic attack on the socio-biological theory of the evolution of human nature. I fancy his chances in this tilt at those windmills are even less than those of the Knight of the Doleful Countenance. Lets start with what every school boy knows. Human nature exists, and organized group aggression is a part of it. Military units are simply hunting parties who are seeking out human prey. Few people would deny that hunting is part of human nature, we have evolved to chuck spears.

    Human nature  as it evolved during the development of agriculture became even more aggressive. Agriculture drastically changed the selection environment faced by the Eurasian races and certainly encouraged the formation of large political units with valuable resources stocks. It is no accident that evidence for war started to pop up after a couple of thousand years of agricultural development.

    The Horgan fallacy is to assum that a fixed human nature, such as it is, was laid down in no later than the late Pleistocene Epoch, some hundreds of thousands of years ago. To be fair, many ‘just-so” evolutionary psychologists also make the Environment of Evolutionary Adaptedness assumption. Since the archaeological evidence for war-like conflict between organized human groups is only about 10,000 years old it follows that war must be a cultural invention, rather than a natural adaptation.

    The fallacy is immediately obvious once the reasoning is laid out. In truth, human genetic evolution can proceed quite rapidly, in a changing environment significant changes in gene frequency can occur over hundreds, rather than hundreds of thousands of years. For example the Azkhenazi Jews experienced a massive genetic boost to their IQs once they moved into a medieval environment that favoured the selection of children with facility at mental arithmetic.

    The genetic basis for human nature was not set in stone in the Pleistocene Epoch. Current research indicates that human genetic evolution increased in pace with the discovery of agriculture at the dawn of the Holocene Epoch, some 12,000 years ago. This research is laid out in detail in Cochran & Harpendings The 10,000 year Explosion. Wikipedia summarises their argument:

    Cochran and Harpending put forward the idea that the development of agriculture has caused an enormous increase in the rate of human evolution, including numerous evolutionary adaptations to the different challenges and lifestyles that resulted. Moreover, they argue that these adaptations have varied across different human populations, depending on factors such as when the various groups developed agriculture, and the extent to which they mixed genetically with other population groups.[2]

    Such changes, they argue, include not just well-known physical and biological adaptations such as skin colour, disease resistance, and lactose tolerance, but also personality and cognitive adaptations that are starting to emerge from genetic research. These may include tendencies towards (for example) reduced physical endurance, enhanced long-term planning, or increased docility, all of which may have been counter-productive in hunter-gatherer societies, but become favoured adaptations in a world of agriculture and its resulting trade, governments and urbanization.

    The authors suggest we would expect to see fewer adaptive changes among the Amerindians and sub-Saharan Africans, who have farmed for the shortest times and were genetically isolated from older civilizations by geographical barriers. In groups that had remained foragers, such as the Australian Aborigines, there would presumably be no such adaptations at all. This may explain why Indigenous Australians and many native Americans have characteristic health problems when exposed to modern Western diets. Similarly, Amerindians, Aboriginals, and Polynesians, for example, had experienced very little infectious disease. They had not evolved immunities as did many Old World dwellers, and were decimated upon contact with the wider world.[2]

    What is significant here is the timing: The Holocene Epoch gave birth to both Agriculture & War, the former creating the environmental conditions for the selection of genes for the latter. Farming man gave birth to fighting man. This all happened within the space of a few thousand years, but left a massive heritable imprint on our genome due to the strength of the founder effect. The Cochran-Harpending theory  also explains why modern Hunter & Gatherer races seem to lack the propensity for organized mass warfare: they did not undergo the agricultural phase of human evolution.

    Of course you would never know this by reading Horgan’s blog or articles which have kept up a steady stream of fire against the scientific study of human nature for the past two decades or so. Including the recent shameful episode when he suggested that socio-biological study or race should be banned. Lets hope my refutation of his latest tissue of nonsense brings him to his senses.

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  2. 2. Eggnogstic 10:07 am 08/2/2013

    Corroborating Margaret Mead? Is she due for a rehabilitation? “Vanishingly little archeological evidence” applies to many specific human activities dating beyond 10,000 years ago in general.

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  3. 3. k banco 10:25 am 08/2/2013

    I sense though that if in the deep past early humans had the weaponry and sufficient density, they would have waged war if it helped them. Nothing has changed biologically since then. I don’t think there is necessarily something biological in us that ‘urges’ us to war. War is and probably always was something more practical to be done when the situation called for it. War is an advanced social skill that would have been lacking in early humans.

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  4. 4. jerryd 3:39 pm 08/2/2013

    A bunch of bull on both sides.

    Facts are before 5500 there wasn’t enough people to bother. Most likely helped the others instead of war as together they could protect themselves from bears, tigers and all kinds of other things that want to eat them.

    Also hunting big animals you need more to take them down. So more people was a big plus until resources started getting overused.

    Again little need for war as just surviving was enough to keep them busy.

    At least until overcrowding and fixed farms gave people something to fight over and people to fight with.

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  5. 5. outsidethebox 7:47 pm 08/2/2013

    Instead of looking so far afield, lets look right here at home. Did indigenous native American tribes who were mostly (but not exclusively) hunter gatherers go to war with each other long before Europeans came? You betcha! So much for that ridiculous theory

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  6. 6. Jack Strocchi 8:13 am 08/3/2013

    I will try to put the argument of the 10,000 year revolution in an Occams Razor form, simple & sharp enough to penetrate the thick hide of ideology surrounding Horgans social constructivism.

    The discovery of agriculture in the early part of the Holocene interglacial was caused/accompanied by a genetic change in the Eurasian races which appears to have facilitated large group co-operation & competition. The formation of political units gave these populations the capacity to both administer large scale agricultural economies and mobilise large military forces.

    The agricultural revolution theory explains why non-agricultural Pleistocene and modern day hunter & gatherer peoples seem to show little evidence for large scale military endeavour. This absence of evidence is the flimsy basis for Horgans “war is a cultural construct” thesis.

    More generally the instinct for group aggression is obviously hard-wired into humans, deriving from our genetic nature as tool-using carnivorous mammals. That is, pack-animals that have evolved to use weapons hunt other species.

    Its obvious that this group aggression propensity is easily turned onto other other members of our own species, in domains such as war, sport and corporate take overs.

    Every schoolboy knows this. It takes a post-modern liberal to unknow it.

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  7. 7. LarryW 9:56 pm 08/3/2013

    Chimpanzees make war. That is well documented. It certainly can be that war evolved separately for chimpanzees and for humans, but for the sake of argument let’s say not. Since the studies show the lines split about 6.4 mya, can’t we say with the same degree of confidence that our commons ancestor some 6.4 mya had by then evolved behavior akin to war?

    I don’t know how “recently” is defined, but I’d say 6.4 mya is not recent.

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  8. 8. CherryBombSim 11:32 pm 08/3/2013

    10,000 years is 400 generations, which is plenty of time for strong selection to have an effect on traits. I haven’t studied this, but my gut feeling is that mass slaughter of young males is going to exert extreme selection pressure. However it originated, war has definitely had an evolutionary impact.

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  9. 9. marclevesque 7:37 pm 08/4/2013

    Some thoughts after reading the comments.

    It’s clear to me that war depends on innate and cultural factors, and that innate traits alone do not lead us to what we today call war.

    Cultural is the main force shaping humans into believers, nonetheless of which are the cultural beliefs of the political and military leaders, leaders who are mostly in a class apart, and themselves physiologically and emotionally distant from the violence and destruction.

    War is an inefficient, if not bankrupt, way to resolve conflict, and we are not bound to it by biology.

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  10. 10. M Tucker 2:22 pm 08/5/2013

    “I understand why many greens and lefties are attracted to the notion that global warming may lead to war. But the evidence for this thesis is weak, and uncritical acceptance of it may lead not to a phase-out of fossil fuels but to a bigger military budget.”

    So we might end up with a bigger military budget because “lefties and greens” will support legislators who call for a “bigger military budget?” You need to support that claim with evidence. Who is calling for a larger military budget? Name the legislators. Your weak attempt at labeling “greens and lefties” fear mongering war hawks is appalling.

    The right wing war hawks and the opponents of government regulations for clean water and air however have many legislators calling for an increase to the military budget, even if the military is not asking for more. They oppose all legislation for energy efficiency even if the military would like to use less gasoline and diesel to produce energy.

    Even if food riots and unrest due to lack of freshwater and access to electricity do not lead to international conflict they can still destabilize a region. If a nation descends into civil war or becomes a failed state that means that hunger will proliferate, health care and monitoring of infectious disease will stop, and neighboring states will be negatively impacted. We see that today and we will have to see what the future holds for Egypt and the Sudan or for Pakistan and India. The actual ramifications of climate impacts and resource shortages, of course, are never as simple as someone like McKibben makes it sound or as unsupported and fallacious as you make it sound.

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  11. 11. RichardEEvans 5:10 pm 08/5/2013

    The weight of evidence robustly indicates that Horgan’s conclusions are wrong. Read Wrangham’s “Demonic Males,” Otterbein’s “How War Began,” Stringer’s “Lone Survivors,” and biochemical papers by DeDreu and Greer, D. LeMarquand, S.R. Wersinger and E. I. Ginns, Couppis and Kennedy, and many others, including the attached.
    /Users/reevans/Desktop/AGG MS evans.doc

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  12. 12. uppitywoman 5:41 pm 08/5/2013

    As mentioned above, chimpanzees wage war, so it’s quite possible that this tendency to regard out-groups with suspicion goes way back, before 10,000 years ago. See Jared Diamond’s book “The World Until Yesterday” for details of inter-tribal warfare among hunter-gatherers world-wide.
    I don’t know why some of you try to turn this into a liberal/conservative issue. Could it be your deeply ingrained fear of “the Other?”

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  13. 13. Booker 8:26 pm 08/5/2013

    A number of commenters have noted that chimpanzees participate in “warfare” and that that could mean that our own war behavior could go back a very long way. It must be remembered though that the behavior of Bonobos is more along the lines of “make love, not war”, and we are just as closely related to them. It’s quite a leap to extrapolate specific behaviors of other primates to ourselves and then say we must therefore be hardwired for that behavior. Is it even hardwired in chimpanzees, or has it varied over time and in different populations?

    It seems to me that Horgan is sticking to the evidence available now, and the evidence of warfare is weak for that time period, so far.

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  14. 14. M Tucker 3:59 pm 08/6/2013

    From Peter Denton’s review of John Horgan’s book “The End of War” as well as two others: Joshua Goldstein’s “Winning the War on War” and Steven Pinker’s “The Better Angles of Our Nature.”

    “I believe Horgan is correct to say that better choices would lead to less violence of all kinds, and ultimately, to more peace. The potential to make those kinds of choices – with large-scale effects – makes our “ethical moment” the most crucial in human history.”

    So John, since we both reject that war is “a biological necessity” what is the right thing to do in Syria? What is the better choice?

    “If we all want peace – and every sane person does – surely we’re smart enough to achieve it. Or rather, choose it. When we start believing that we can end war, we are already well on our way.” (from John’s book)

    So why not attack a real world problem instead of marching out on this crusade to smite the dragon of “war is a biological imperative.” Will winning that war help solve Syria’s civil war? – The ‘believing’ is an easy matter compared with the doing isn’t it? Do you have a suggestion that does not involve war (you know, arming the rebels)? What do we do if only the rebels want to join in negotiations? How do we impose sanctions if Russia will support the Syrian regime? Impose sanctions on Russia? Aren’t sanctions just another form of violence? After all the intended effect is to make them suffer.

    Anyway, since we are smart enough we must be well on our way don’t you think?

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  15. 15. marclevesque 11:24 am 08/7/2013

    Corrections to my last comment

    “Cultural is the main force shaping humans into believers, nonetheless of which are the cultural beliefs of *some/many* political and military leaders, leaders who are mostly in a class apart, and themselves physiologically and emotionally distant from the violence and destruction.”

    And the cultural beliefs I refer to are not restricted to political and military leaders or to the class they habitually occupy (in other words, these beliefs are spread out through society though they may be more concentrated in the loosely termed upper classes).

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  16. 16. Manruss 1:10 pm 08/7/2013

    I can understand cautioning people against claiming that global warming will certainly cause wars based on historic or archaeological evidence, but it seems just as foolish to conclude that global warming won’t cause them. One doesn’t have to look beyond the 20th century to know that resource competition and poverty do cause, or at least set the table for, armed conflict. And it seems fair to suggest that conflicts may arise in the 21st century as populations compete for dwindling water and food supplies brought about by melting and desertification.

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  17. 17. Manruss 1:14 pm 08/7/2013

    The fact that war did not become a common feature of civilizations until the Bronze Age doesn’t really dispel the innateness of war as a human characteristic, in my view, so much as it demonstrates that human conflicts scale up or down based on our material capacity to facilitate them.

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  18. 18. BuckSkinMan 1:14 am 08/9/2013

    An amazingly blinkered argument. The very obvious fact about humans is that they organize into specialized groups with more aggressive members becoming protectors and “police” of their troop or community. In other apes this usually falls to a single dominant male who sometimes has “lieutenants.”

    Jane Goodall was the real scientist investigating our closest human relatives in real time. The myth that chimps are pastoral was blasted by her discovery of “wars” and gang attacks between different (not obviously different, just different as potential competing ) groups.

    The chief difference between human and apes and monkeys (the entire anthropic order) is that humans went from the same kind of direct “hand to hand” battling to the use of improvised weapons and from there to weapons technology not seen in any other species on Earth.

    What’s interesting in our Post Rational / Post Scientific Age is the dominance of the less aggressive male. It’s the Peacenik Phenomenon.
    (aka, Massive Denial). This phenomenon is the product of expanded populations and remote communications. We no longer have tribes or troops and our specialization has become categorization. So these less aggressive “better scholars” have developed a subconscious and conscious strategy to “defend” against aggressive (unscholarly) males who are, in reality, still the defenders of their “community” – aka, nation.

    Notice the amateurish miss in the theory of “Peaceable Apes Gone Wrong Lately” – that there might be NO sign of war before implement technology shows that, before spear chucking, our ancestors were killing with hands and teeth: just like the other apes. There’s massive evidence of this deceptive strategy of denial: the theory often involves assumptions which include the notion of the “uselessness” of both armed individuals and armies. The Classic Example is the common practice of prohibiting even armed defenders from “zones” around schools. Thus we see see armed attackers having an easy job of killing disarmed teachers and their students.

    It’s distressing to see that the defended now fear their own defenders in such fear-driven ways. It’s also distressing to see alleged “scientists” joining the propaganda war on the defenders within our own species.

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  19. 19. marclevesque 11:42 am 08/10/2013


    “these beliefs are spread out through society though they may be more concentrated in the loosely termed upper classes”

    Over stepped myself again. I don’t think individuals who are more ready to privileged warfare are more concentrated in upper classes. Trying for scope at the expense of accuracy.

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  20. 20. Asgard 8:05 am 08/11/2013

    Another desperate, totally unconvincing post from Horgan which tells more about his own motivations than about the origins of war.

    For Horgan, his side is “skeptical” whereas the other side is “simplistic”. Let’s take a closer look.

    For the so-called Deep Rooters, war is innate. But what do they mean by “innate” (assuming that they ever use that term)? They certainly don’t mean that war has always existed or will always exist in the future. Therefore, arguing that war is not ubiquitous and is not inevitable is not the same thing as arguing that it is not innate. To think that “innate” implies “inevitable” is a simplistic understanding of the Deep Rooters’ view.

    Or take “skeptical”. Horgan says that other researchers are treating the recent Science report on the relation between temperature and violence skeptically. But reseachers are treating the Science report on the paucity of ancient warfare skeptically as well. There has been a lot of discussion in the blogosphere about the validity of the study’s conclusions. Have we seen any of it on Horgan’s blog? No. He has accepted the report uncritically. Apparently, Horgan is critical and skeptical only when the findings clash with his pet theory.

    You can learn a lot by reading Horgan’s blog posts. But you can’t take him seriously. That’s because he is not honest. That’s a mortal flaw for an intellectual.

    How about this simple attempt at a synthesis: Tendency for intergroup violence (and by extension, tendency for war) is innate. But you don’t, or can’t, make war unless there are sufficient incentives, equipment, organizaton, ideology etc. in your society that facilitate war making. In other words, a “culture of war” is as necessary as an “innate tendency for war” to make wars happen. War is both deeply rooted and a cultural thing. But it is neither inevitable nor a cultural invention.

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