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Quitting the hominid fight club: The evidence is flimsy for innate chimpanzee–let alone human–warfare

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


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chimpanzees in a groupExtraordinary claims, Carl Sagan liked to say, require extraordinary evidence. Here is an extraordinary claim: "Chimpanzeelike violence preceded and paved the way for human war, making modern humans the dazed survivors of a continuous, five-million-year habit of lethal aggression."

The anthropologist Richard Wrangham of Harvard University made this statement in his 1996 book Demonic Males: Apes and the Origins of Human Violence (Houghton Mifflin, co-written with journalist Dale Peterson) and has reiterated it ever since. He asserts that both male humans and chimpanzees, our closest genetic relatives, are "natural warriors" with an innate predisposition toward "coalitionary killing," which dates back to our common ancestor.

The theory has been touted by such influential intellectuals as the philosopher Francis Fukuyama of Johns Hopkins University and the psychologist Steven Pinker of Harvard. "Chimpicide," Pinker wrote in his 2002 bestseller The Blank Slate the Modern Denial of Human Nature, "raises the possibility that the forces of evolution, not just the idiosyncrasies of a particular culture, prepared us for violence."

A new study seems to corroborate Wrangham’s demonic-males thesis. A group led by John Mitani of the University of Michigan at Ann Arbor observed a troop of chimpanzees in Uganda’s Kibale National Park killing chimps from neighboring troops during a 10-year period of "territorial expansion". This "warfare," Nicholas Wade reported in The New York Times, suggests that "both humans and chimps inherited an instinct for aggressive territoriality from their joint ancestor."

I’ve been reading and talking to anthropologists about the demonic-males theory for years, and I’ve turned from a believer to a skeptic. Here are some reasons why:

Wrangham and other chimpanzee researchers often present the rate of "intercommunity killing" in terms of annual deaths per 100,000 population. Mitani, for example, estimates the mortality rate from coalitionary attacks in Kibale to be as high as "2,790 per 100,000 individuals per year." But the researchers witnessed only 18 coalitionary killings. All told, since Jane Goodall began observing chimpanzees in Tanzania’s Gombe National Park in 1960, researchers have directly observed 31 intergroup killings, of which 17 were infants.

I obtained these figures by adding numbers from a 2006 paper by Wrangham and two colleagues and from the new report by Mitani’s group. Researchers have "suspected" or "inferred" a few dozen more lethal attacks, in which a chimpanzee is found dead or simply disappears. All these violence statistics, according to an analysis published this year by the anthropologists Robert Sussman and Joshua Marshack of Washington University in Saint Louis (W.U.), are based on 215 total years of observations at nine different sites in Africa. In other words, researchers at a typical site directly observe one killing every seven years.

Wrangham conceded in a response to Sussman and Marshack, published in the same volume as their analysis, that chimpanzee coalitionary killings are "certainly rare." He also acknowledged that "there are various sites where scientists have studied chimpanzees without any record of coalitionary killing or other kinds of violence." He suggests that these nonviolent chimpanzees are not "habituated" to their human observers or are isolated from other communities. But that raises another question: Could unusual environmental conditions be triggering intergroup chimpanzee killing?

The first lethal gang attack was witnessed in 1974 at Gombe, after Goodall and her co-workers had spent 14 years closely observing chimpanzees. Goodall, who began supplying bananas to chimpanzees in 1965, once expressed concern that the feeding "was having a marked effect on the behavior of the chimps. They were beginning to move about in large groups more often than they had ever done in the old days. Worst of all, the adult males were becoming increasingly aggressive. When we first offered the chimps bananas the males seldom fought over their food; …now…there was a great deal more fighting than ever before." (This quote appears in Sussman and Marshack’s paper.)

Chimpanzees throughout Africa are also increasingly threatened by poachers, farmers and other humans. Ian Tattersall, an anthropologist at the American Museum of Natural History, told me that chimpanzee violence is "plausibly related to population stress occasioned by human encroachment." In other words, outbreaks of lethal violence among chimpanzees may stem primarily from environmental and even cultural factors. Wrangham himself has emphasized that chimpanzees display "significant cultural variation" in tool use, courtship and other behaviors.

Another challenge to Wrangham’s theory is Pan paniscus, otherwise known as the pygmy chimp, or bonobo. Bonobos are darker-skinned and slimmer than Pan troglodytes, the more common chimpanzee species, and much less aggressive. Researchers have never observed coalitionary killing among bonobos. Noting that bonobos are just as genetically related to us as chimpanzees, Frans de Waal, a primatologist at Emory University, suggested last year in The Wall Street Journal that bonobos may be "more representative of our primate background" than are chimpanzees.

As evidence, de Waal cited new studies of Ardipithecus ramidus, or "Ardi," who roamed Ethiopia 4.4 million years ago and is the oldest known human ancestor. Although the species was first discovered in the early 1990s, its evolutionary significance was only spelled out in detail last fall in a multipaper report in Science. One author, anthropologist Owen Lovejoy of Kent State University, told me that Ardi has triggered a "tectonic shift" in views of human evolution. "We now know, especially in light of Ardipithecus, that hominids have always been a far less aggressive clade than are chimpanzees or even bonobos."

Male and female Ardipithecenes were closer in size than male and female chimpanzees and hence more likely to engage in pair-bonding. Ardi also lacked the fanglike canines that chimpanzees employ as weapons. These traits of minimal sexual dimorphism and small canines persisted in later hominid species such as Australopithecus and Homo erectus, which emerged four million and two million years ago, respectively.

There is also no fossil or archaeological evidence that our ancestors fought millions or even hundreds of thousands of years ago. Yes, archaeological digs and modern ethnography have established that warfare was common among pre-state societies, notably hunter–gatherers; our ancestors are thought to have lived as hunter–gatherers since the emergence of the Homo genus two million years ago. Advocates of the demonic-males thesis suggest that if hunter–gatherers ever engaged in warfare, they must have always done so.

But as the anthropologist Douglas Fry of Åbo Akademi University in Finland pointed out in his book Beyond War: The Human Potential for Peace (Oxford University Press, 2009), the oldest clear-cut relic of group violence is a 13,000-year-old grave along the Nile River in the Jebel Sahaba region of Sudan. The grave contains 59 skeletons, 24 of which bear marks of violence, such as embedded projectile points. The oldest known murder victim was a young man who lived 20,000 years ago near the Nile about 200 miles downstream of the Jebel Sahaba site; two stone projectile points were embedded in his pelvic bone.

Evidence of earlier lethal human violence is ambiguous, at best. One example is a 50,000-year-old male Neandertal, found in Iraq’s Shanidar Cave, whose ribs were pierced by a sharp object; he lived for several weeks after being wounded. The wound may have resulted from a fight with another Neandertal, according to the anthropologist Erik Trinkaus of W.U. But most Paleolithic injuries probably resulted from "hunting large animals who object to being speared," Trinkaus told me. "You find a lot of evidence of bumps and bruises and broken bones" among Neandertals and other early humans. "There is absolutely no evidence," Trinkaus says, that "war is continuous back to the common ancestor with chimps."

Advocates of the demonic-males thesis insist that absence of evidence of warfare does not equal evidence of absence, especially given the paucity of ancient human and prehuman remains. The absence-of-evidence argument, anthropologist Brian Ferguson of Rutgers University told me, "would be valid if the earlier skeletal and settlement remains were so limited that they would not reliably reveal war." In fact, many regions around the world yield evidence of human habitation "for centuries, even millennia, with no indications of war." For example, excavations have revealed that people settled in Abu Hureya, near the Euphrates River, 11,500 years ago, and lived there for more than 4,000 years while leaving no signs of violence.

Meanwhile, Ferguson notes, "unmistakable" signs of group violence emerged in other regions in northern Africa, the Middle East, Europe, Asia, Australia and the Americas. The evidence consists of skeletons with crushed skulls, hack marks and projectile points embedded in them; rock art depicting battles with spears, clubs, and bows and arrows; and fortifications for protection against attacks. These relics indicate that warfare arose as humans began shifting from "a nomadic existence to a sedentary one, commonly although not necessarily tied to agriculture," Ferguson says.

Archaeologist Jonathan Haas of the Field Museum in Chicago concurs: "There is a very tiny handful of incidences of conflict and possible warfare before 10,000 years ago. And those are very much the exception." In an interview with me he attributed the emergence of warfare in prehistory to growing population density, diminished food sources and the separation of people into culturally distinct groups. "It is only after the cultural foundations have been laid for distinguishing ‘us’ from ‘them,’" Haas says, "that raiding, killing and burning appear as a complex response to the external stress of environmental problems."

On the other hand, Haas adds, "groups that are at war in one era or generation may be at peace in the next." War’s recent emergence, and its sporadic pattern, contradict the assertion of Wrangham and others that war springs from innate male tendencies, he argues. "If war is deeply rooted in our biology, then it’s going to be there all the time. And it’s just not," he says. War is certainly not as innate as language, a trait possessed by all known human societies at all times.

Defenders of the demonic-males theory often accuse critics of being peaceniks who hope that war will be easier to abolish if it isn’t innate. I am, I confess, a peacenik. But my criticism—and that of other critics I’ve cited—stems from science, not ideology. The evidence for the demonic-males theory, far from extraordinary, is flimsy.

Image: chimpanzees, courtesy of Wikimedia Commons

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  1. 1. gunslingor 2:47 pm 06/29/2010

    Teritorial disputs are common amoung most mammals. Murder is not so common and detering is the goal of disputes.

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  2. 2. brian hare 3:47 pm 06/29/2010

    Hemingway famously suggested we should only write about what we have experienced. My suggestion to the author is to go witness the integration of two strange chimpanzee males together at a zoo or sanctuary…..you would not be able to write this column if you had. The authors you are critiquing spent decades thinking about this problem…how much effort did you really put into forming your opinion that you express so strongly here?

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  3. 3. glama 6:15 pm 06/29/2010

    brian hare completely missed the point of the discussion about chimpanzee behavior, which is the lack of lethal violence in the a natural context, not the occurrence of skirmishes when zoos force together unfamiliar individuals.

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  4. 4. glama 6:15 pm 06/29/2010

    brian hare completely missed the point of the discussion about chimpanzee behavior, which is the lack of lethal violence in the a natural context, not the occurrence of skirmishes when zoos force together unfamiliar individuals.

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  5. 5. Marc Levesque 6:54 pm 06/29/2010

    @brian hare

    He probably put a lot of thought into it.

    The examples you state are not indicative of chimpanzee behaviour per say, but rather they are examples of human constrained chimpanzee behaviour.

    For example, to put this in context, it would be a stretch to call the behaviour of two cocks in a ring normal cock behaviour just as it would be a stretch to consider the behaviour of gladiators in a roman ring normal inter human behaviour.

    Those examples may seem extreme but they are not that far from yours there is a continuum. Animal behaviour in a sanctuary, zoo, prison, ring, etc are not good models to study nomalus behaviour, though they are maybe good models to understand what kinds of overarching constraints should be avoided if one wishes to reduce the overall incidence pathological behaviour.

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  6. 6. brian hare 7:45 pm 06/29/2010

    I hate to say but chimpanzees in captivity do exhibit natural behavior when they are integrated…and this is when caring and professional animal keepers are doing everything to PREVENT aggression. All wild populations have been seen to commit lethal aggression and chimpanzees kill or severely injure one another at very high frequency in captivity. It it extremely difficult to integrate them (as well as gorillas and male orangutans). Across all environments that chimpanzees have been observed if there are multiple males in separate groups you have extremely severe aggression if they are brought together. Meanwhile bonobos who live in identical captive conditions do not do any of this. It is as simple to put a bonobo in a new group as it is to put a goldfish in a gold fish pond….I have seen it all for 15 years of work in labs, zoos, and sanctuaries in Africa. This is the danger of only relying on natural observations. Natural observations are best viewed together with captive observations and experimental manipulation if we want to understand animal psychology.

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  7. 7. davideconnollyjr 8:04 pm 06/29/2010

    Perhaps you have been living on another planet? Maybe you are one of those that believe "Guns kill people?" Let’s make it real easy to connect with- when you drive home after a hard day at work, and someone is parked in your spot, in front of your house, most people automatically think that their space has been invaded, in spite of the fact that legally, the street is public property, and anyone is free to park there. If the parking space were actually your designated parking space, say, at the university, then most people would know they had every right to feel angry about the invasion of their space. These possessive feelings are deep because they are partly encoded. Getting beyond desire, and the need to posses things, and people is part of our journey toward becoming fully human. Deal with the facts.

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  8. 8. Dr. Paradox 10:26 pm 06/29/2010

    One of the best anti-war pieces I’ve seen from you yet, Horgan.

    It also brings to (my) mind Sheri Tepper’s novel The Gate to Women’s Country, and the role of females in allowing and/or ‘rewarding’ large-scale aggression and/or aggressive tendencies in males…

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  9. 9. glama 11:08 pm 06/29/2010

    If we’re going to go with unnatural settings to judge innate behavior, I suppose we should see what chimps do when forced to live underwater in scuba gear, in a tank of water on the moon and in total darkness for 24 hours a day. Whatever they do, we can then say is their "innate" behavior, and consider it an insight to our own nature.

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  10. 10. brian hare 12:58 am 06/30/2010

    Glama – you might want to visit a AZA accredited zoo sometime or a PASA sanctuary in Africa (got to pasaprimates.org)…there is not one shred of evidence that the animals held in such enriched captive environments are cognitively any different from wild chimpanzees. If so, I welcome the citation of the paper. To say captive chimpanzees can tell us nothing about chimpanzee psychology is likely saying humans who work in a small office all day on wallstreet cannot tell us anything about human psychology. The scuba gear / moon analogies don’t work. sorry. As for "innate" what does that mean to the author and to you I wonder? All behavior is determined by an interaction of genes and environment and I can assure you that the researchers observing chimpanzee aggression are well aware of this….also please answer why bonobos which are only a few 10th of a percentage different from chimpanzees do not show the same aggression that chimpanzees show in teh wild or in captivity……

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  11. 11. dudeinhammock 3:18 am 06/30/2010

    Thanks for this unusual skeptical look at this issue, which I’ve written about as well (in Sex at Dawn, which is published today, in fact).

    One point I’d disagree with though. You wrote, "Male and female Ardipithecenes were closer in size than male and female chimpanzees and hence more likely to engage in pair-bonding."

    This isn’t quite right. More similar m/f size does indicate that humans weren’t polygynous (one male with female "harems"), but does not necessarily indicate monogamy, merely limited male/male conflict over mating. Promiscuity is, for many reasons we discuss in our book, a far more likely scenario.

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  12. 12. dudeinhammock 3:23 am 06/30/2010

    Sorry, one more point, having read more recent comments. Brian Hare is one of the world’s up-and-coming experts on primate behavior, and he’s certainly correct about chimp intra-group aggression. But the question raised in the article is whether this male/male chimp aggression is a logical antecedent to human war.

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  13. 13. dewaal 5:29 pm 06/30/2010

    It is hard to disagree with Brian Hare that chimpanzee males are xenophobic and can be terribly violent. The observations in the field also cannot be explained away by food provisioning, as some have tried, because the same observations are now known of unprovisioned field sites.

    The problem arises when we try to jump from chimpanzee behavior to warfare in the last common ancestor, and conclude that there must have been 6 million years of continuous human warfare. This is a tricky extrapolation based on the idea that the last common ancestor must have been chimp-like. We don’t know this at all. This creature could equally well have been gorilla-like or bonobo-like, or even different from all extant African apes. Combined with other evidence reviewed by John in his excellent article, the connection between chimp aggression and human warfare is tentative at best.

    I would moreover add that modern human warfare has little to do with aggression in the animal sense. Does anyone think that Napoleon’s soldiers marching into Siberia were in an aggressive mood, or that American soldiers are in such a mood when they fly to Iraq? If aggression is not the prime mover of human warfare, the whole comparison falls apart, doesn’t it?

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  14. 14. lianania 6:48 pm 06/30/2010

    It is a crappy paper and a crappy polemic and always one-sided – What is MUST be genes, after all i see it all the time and when I don’t see it, it is an exception because look , there it is again. And what is this polemic really discussing? Aggression? Well, if you kick a dog, after a while even the best behaving beast will show his or HER teeth. Yes gals are aggressive too. not just MALES. And gals love sex too and cheat, not just males – I thought I throw this one in.

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  15. 15. dudeinhammock 7:11 pm 06/30/2010

    dewaal wrote: "I would moreover add that modern human warfare has little to do with aggression in the animal sense. Does anyone think that Napoleon’s soldiers marching into Siberia were in an aggressive mood, or that American soldiers are in such a mood when they fly to Iraq? If aggression is not the prime mover of human warfare, the whole comparison falls apart, doesn’t it?"

    This is an excellent point that is rarely raised in these discussions. I’m reminded of a recent interview I saw with Sebastian Junger, who’s just published a book on his experiences embedded for five months with a unit in Afghanistan. When he was asked why these guys fought, he answered: "Love." His point was that they’re not angry or acting out of an aggressive impulse, they fight in order to protect their brothers in arms.

    This, it seems to me, makes war even more tragic.

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  16. 16. Marc Levesque 7:28 pm 06/30/2010

    @Brian Hare

    I have to correct myself. I think you can gain tremendous insight into animal psychology from animal behavior in captivity, I did not mean to imply the contrary.

    You did not imply the following (and it was probably my main target in my first response) : what I do object to is the idea that perpetual human warfare is genetically driven and the proof is that wars do occur.

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  17. 17. Siegfried Hannig 4:38 pm 07/1/2010

    Austrian ethologist Wulf Schiefenhövel found that one-quarter of the male hunter gatherers among the Eipo people in the rain forest of Papua New Guinea die violent deaths. Almost identical findings were reported by American anthropologist Napoleon Chagnon among male hunter gatherers in the Amazon rain forest.

    These findings among the arguably most primitive contemporary humans appear to leave no doubt whatsoever about the demonic nature of human males. However, I submit that their violent encounters are clashes between strangers who are effectively identified as enemies. Therefore their killing may effectively be regarded as being of a defensive nature, even when an attack is a deliberate act of aggression.

    In a fairly recent video with Richard Wrangham I understood him to be suggesting a similar defensive motivation among chimpanzees on killing patrols, but I may have misunderstood him.

    I would certainly dispute the most recent hypothesis of John Mitani that warring chimpanzees kill each other "to expand their territories at the expense of their victims". Instead I would say their killing is designed as a defensive deterrent.

    Siegfried Hannig <shannig@telkomsa.net>

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  18. 18. bucketofsquid 4:17 pm 07/6/2010

    Demonic male is such an idiotic term. Ancient earth spirits have nothing to do with human behavior. Every male has a mother. Besides, it has long been proven that women commit significantly more murders (out side of war) than men. This is 1960s style militant lesbianism embraced by guilty feeling men.

    Humans have wars because they work. That is why nuclear war is a deterent. Nuclear war does not increase usable territory or resources. It just makes you die. Conventional wars increase territory and resources so they keep happening.

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  19. 19. bshields 12:00 am 08/25/2010

    As a history teacher and student of history, I have to say that I see the main driving force of organized violence, or war, as being the greed and lust for power of ruling elites. Humans are clearly capable of violence. We are also capable of nonviolence. Most Native Californian groups, for instance, used effective, diplomacy based forms of conflict resolution. This lasted for centuries, even millennia. They had their problems and tensions, but they lived in societies based on cooperation and negotiation. There are examples of both warlike and peaceful societies in history. As war hero President Eisenhower advised, watch out for the military-industrial complex. I’m serious – do you think the wars in Iraq and Afghanistan are more about our supposedly innate violent tendencies or Exxon’s bottom line?

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  20. 20. Evelyn Haskins 3:50 am 08/26/2010

    If we humans are NOT innately warmongering, then WHERE did it come from??

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  21. 21. Evelyn Haskins 4:06 am 08/26/2010

    Sorry Folks,

    Last time I read about it, Exxon was owned and run by humans.

    And the so called ‘war in Afghanistan has been going on for centuries — well before Exxon existed.

    And IF chimps and humans (and cockerels, and Japanese fighting fish and seal lions, etc) all respond to violence against con-specifics when the going gets crowded or resources are limited, then THAT aggression is INNATE.

    And brothers fight each other, and young men become football hooligans and gang members. No non-human factor is responsible for such behaviours

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  22. 22. Evelyn Haskins 4:20 am 08/26/2010

    Sorry Folks,

    Last time I read about it, Exxon was owned and run by humans.

    And the so called ‘war in Afghanistan has been going on for centuries — well before Exxon existed.

    And IF chimps and humans (and cockerels, and Japanese fighting fish and seal lions, etc) all respond to violence against con-specifics when the going gets crowded or resources are limited, then THAT aggression is INNATE.

    And brothers fight each other, and young men become football hooligans and gang members. No non-human factor is responsible for such behaviours

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  23. 23. pink_trike 5:30 pm 09/6/2010

    "The oldest known murder victim was a young man who lived 20,000 years ago near the Nile about 200 miles downstream of the Jebel Sahaba site; two stone projectile points were embedded in his pelvic bone."

    "One example is a 50,000-year-old male Neandertal, found in Iraq’s Shanidar Cave, whose ribs were pierced by a sharp object; he lived for several weeks after being wounded."

    Both of these examples are likely cases of ritual sacrifice, rather than murder. To describe these cases as "murder" imposes a modern value judgement. Ritual sacrifice by piercing the side or pelvis is a common theme in ancient records (so-called "myths"( from all over the globe.

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  24. 24. pink_trike 5:39 pm 09/6/2010

    "The oldest known murder victim was a young man who lived 20,000 years ago near the Nile about 200 miles downstream of the Jebel Sahaba site; two stone projectile points were embedded in his pelvic bone."

    "One example is a 50,000-year-old male Neandertal, found in Iraq’s Shanidar Cave, whose ribs were pierced by a sharp object; he lived for several weeks after being wounded. "

    Both of these cases were more likely to be evidence of ritual sacrifice than "murder". Ritual sacrifice by piercing the side or pelvis is a common theme in ancient records (myths) from around the globe, and are also portrayed in very early cave painting. To describe these cases as "murder" imposes a very modern value judgement on what was likely a meaningful ritual in which the presumed "victim" would have been honored to have been chosen to participate in.

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  25. 25. tribalypredisposed 3:12 pm 10/11/2010

    Sadly, very little that Horgan asserts could even theoretically be correct.

    1)Chimps and war. Horgan tries to assert that very few chimps have been documented to be killed and that this is somehow supportive of his views. Absolutely wrong. It is considerably more difficult for chimps to kill each other than it is for humans, a similar number of attempts can be expected to result in far fewer deaths. It is telling that Horgan never breaks down the numbers in terms of deaths as a percentage of populations. But the critical point is that because the behavior occurs at all in chimps we now have evidence that humans possibly could have evolved a predisposition for group coalitional violence as well, since chimps did. Whether or not it is a behavior our mutual ancestor passed to both chimps and humans is not of much significance in the matter.

    Horgan also goes with the notion that perhaps provisioning "caused" war to arise in the chimps that Goodal was studying. This is possibly correct, if the Theory of Evolution is wrong. Horgan’s view is an assertion that a highly complex behavior arose spontaneously and "culturally" as a meme to the point of stability, existing in all members of the group, over a very short period of time due to what must be asserted by those proposing this view to be a unique event; the existence of unequally distributed resources and/or "sress." Sadly for those making these claims, the existence of unequal distribution of resources is a foundational stipulation of the Theory of Evolution, and asserting that chimps began to go to war due to the unequal distribution of resources requires that one accept an evolved predisposition for war in chimps or come up with some farcical reasoning for why chimps waited until the mid-1970′s to evolve that response in some magical way to a common circumstance. This is an extremely "extraordinary claim," and as Horgan has stated above does require extraordinary evidence be supplied by Horgan or his allies.

    2)Similarly, the Horgan and others notion that environmental stress such as drought "causes" war, and therefore war is not an evolved behavior, is held in ignorance of the Theory of Evolution too. Again, changes in the availability of resources is a given in the course of the evolution of humans or any other species; if drought "causes" war now, then it very likely "caused" it for our ancestors as well. Meaning war is an evolved response to a given environmental stimuli that occured many times throughout our evolution.

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  26. 26. tribalypredisposed 3:14 pm 10/11/2010

    3) Horgan is making the "absence of evidence" fallacy. Our ancestors lived in small groups that most likely conducted war as a series of guerilla raids. Based on anthropological data from extent small tribal group wars, most often only one or two people are killed at a time. Even if we find a victim of this type of war, it is impossible to know if it was due to war or to some individual level dispute.

    4)Horgan and others also have a very confused view of what genes do and how human behavior works, to the point that it shocks me. A genetic basis for war in humans, a species that has evolved more than any other for behavioral flexibility, does not mean that war is automatic or autonomic. Even far less intelligent species than us regularly make decisions about whether to engage in high risk conflict or avoid it, mostly in mate competitions. It would be highly maladaptive to evolve a trait to always engage in life-threatening activity with no free will or judgement involved; this kind of automatic war behavior could never evolve. So of course no academic or knowledgable other has ever claimed the straw-man Horgan and many others assert that they are challenging.

    5)Of course the capacity for peace and existence of some few groups that have gone very long periods without war would be expected by anyone with a passing familiarity with both humans and the Theory of Evolution. So it is far from a "counter argument" to the view that humans have an evolved predisposition for war.

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  27. 27. tribalypredisposed 3:19 pm 10/11/2010

    6)Contrary to what we should find if Horgan and his buddies are correct, there are universal patterns of behavior when it comes to war. Enemies are described as some source of group threat; criminal, insane, infectious disease, pest or threat animal, or evil spirit/spell casters. Predictable patterns of "cycles of violence" take place with "punitive" increases of "revenge" and shows of force. Universal pro-in-group bias leads the vast majority to excuse and justify the actions of their own group and suspect and blame out-group. It is this stability of the nature of how we communicate to gain in-group acceptance of a proposed war that allows for optimism about the possibility of ending war BECAUSE it is an evolved predisposition. Knowing what to look for can allow us in the future to make war at least a more rational decision, and not one we are manipulated into making by others with the help of our genetic predisposition for war.

    We should expect that our ancestors engaged in war, and any assertion otherwise would require extraordinary evidence be provided. Humans are a group social territorial species that controls resources at the group level. Evolutionary theory demands that competition for resources occur, as resources are fitness limiting, finite, and unequally distributed. There was no mechanism for this competition at the group level other than war available to our ancestors. Group territorial species all engage in violence at the group level. Lion prides, hyenas, ants, meerkats, chimps, and so on. Species territorial at the individual level also sometimes engage in violence in defense of their territory. Control of territory is control of resources, and competition for resources is the driving selective force of evolution. Looking at a species where nearly every population known has engaged in group level violence, and where group level violence is common, and where universal patterns of behavior exist around the expression of group level violence, and which the Theory of Evolution predicts should engage in group level violence, and asserting that war, the behavior in question, is not an evolved predisposition and is instead cultural is farcically wrong and unscientific, and requires truly extraordinary evidence which has not even been hinted at here or elsewhere.

    Anyone who wants to see my own effort to examine this issue in more detail, and in a way that is consilient with the Theory of Evolution, can see my paper here http://theroadtopeace.blogspot.com/

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  28. 28. hcc2009 3:49 pm 10/25/2010

    Those advocating "the demonic male" often point to sexual dimorphism as a marker of species where male-male competition is key to reproductive success (e.g., antlers). Humans ARE very sexual dimorphic, but I’d argue that mother nature is sufficiently subtle that drawing conclusions about one species based on the behavior of another is ill-advised. The ravages of testosterone in humans (size, muscle mass, and a feeling of invincibility) might have evolved in humans for a completely different reason: bringing down large sources of protein.

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