In the current issue of Cliodynamics: The Journal of Quantitative History and Cultural Evolution the anthropologist Sarah Mathew reviews War, Peace, and Human Nature, edited by Douglas Fry. Fry is one of the large group of anthropologists and other social scientists who have been critical of Steven Pinker’s book The Better Angels of Our Nature.
Sarah makes the following important point about War, Peace, and Human Nature:
Note that the book is not just about warfare, but about conflict in general, which can include a variety of inter-personal conflict, including physical aggression between same-sex individuals, domestic violence, conflict within social relationships, verbal aggression, and alcohol-induced fights. Some readers may find this problematic. The evolutionary forces that shape warfare differ from the evolutionary forces that shape inter-personal violence because warfare can occur only if the problem of collective action is solved. Thus, the evolution of warfare is tightly linked to the mechanisms underpinning the evolution of cooperation. This fact alone accounts for the rarity of warfare in most of the animal kingdom despite the prevalence of myriad other forms of conflict. So, for readers interested in the evolution of warfare, the book may seem like a grab bag of too many unrelated phenomena.
There is a reason why many authors of the book conflate warfare and violence. To see this, I recommend taking a look at a recent article by Azar Gat, Proving Communal Warfare among Hunter-Gatherers: The Quasi-Rousseauan Error.
The target of Gat’s critique is “Rousseauism,” the idea that humans were basically nonviolent before the transition to agriculture and the rise of complex societies—civilization. At the peak of the Rousseauism in the 1960s, anthropologists celebrated Kalahari Bushmen as “harmless people” and wrote books about the Inuits of polar Canada with titles like “Never in Anger.”
These descriptions of peaceful hunter-gatherer groups were revealed by subsequent research to be complete fantasies. The seminal publication that turned the tide against Rousseauism in modern anthropology was the 1996 book by Lawrence Keeley, War Before Civilization: the Myth of the Peaceful Savage.
Meanwhile, another strand developed in the anthropological study of warfare. These researchers did not deny that small-scale societies studied by anthropologists had very high levels of homicide due to warfare, but argued that it was due to the contact of these previously peaceful societies with the intrusive states. According to such anthropologists as Brian Ferguson, expanding states, both modern European colonial powers and ancient empires, create “tribal zones” on their frontiers, in which warfare is frequent and intense. Professional anthropologists who, of course, come from civilized state-level societies study the tribal zone and are fooled to believe that all small-scale societies, even those before exposure to the corrupting influence of the states, are very violent.
Empirical evidence supports the idea that the arrival of centralized states in a region increases the intensity of warfare. But that doesn’t mean that before such intrusion small-scale societies were peaceful.
Gat reviews several lines of evidence, including archaeological, but probably the most convincing is his extended review of what we know about the pre-contact Australia.
Australia was an entire continent inhabited by hunter-gatherers, with no agriculturalists, pastoralists, or states. The first non-foraging society that arrived in Australia was the British, who established the penal colony at the Botany Bay in 1788, and for a while Australia was a dumping ground for the undesirables from the British Isles. It was not until the 1820s when the free settlers started to arrive, and massive immigration began during the Gold rush era, starting in 1851.
Source: Gat 2015
Much before that, in 1803, the 23-year old Englishman William Buckley escaped from a penalty settlement and lived with an Aboriginal tribe for 32 years. His account gives us an invaluable glimpse into the life of a hunter-gathering society before it was changed by the intruding state-level civilization. Buckley was not a trained anthropologist, but that doesn’t disqualify him from reporting on such basic issues as war and peace.
Buckley recounts some dozen battle scenes, as well as many lethal feuds, raids, and ambushes, comprising a central element of the natives’ traditional way of life. He describes their weapons of war in great detail: clubs, spears, “war boomerangs,” throwing sticks, and shields. Tribes typically consisted of 20–60 families each and were egalitarian, without chiefs. There was fighting at all levels: individual, familial, and tribal. Some of the intertribal encounters that Buckley recorded involved large numbers: five different tribes collected for battle; a battle and raid against an intruding enemy tribe, 300 strong; several full-scale intertribal encounters, the last one a raid with many dead; two other encounters, the second against a war party of 60 men. Ceremonial cannibalism of the vanquished was customary. Buckley reported that the large-scale raid was the deadliest form of violence and often involved indiscriminate massacre: “The contests between the Watouronga, of Geelong, and the Warrorongs, of the Yarra, were fierce and bloody. I have accompanied the former in their attacks on the latter. When coming suddenly upon them in the night, they have destroyed without mercy men, women and children.” (Gat 2015)
The Australian evidence is particularly important because it comes from eyewitnesses to the crime, so to speak. Archaeological evidence tells us that violent death was very frequent in prehistoric societies. But it is difficult to distinguish death in war from death resulting from within-group violence. This uncertainty allows Douglas Fry to write, “whereas homicide has occurred periodically over the enduring stretches of Pleistocene millennia, warfare is young, that is, arising within the timeframe of the agricultural revolution.” But the Australian evidence decisively demonstrates that war precedes the agricultural revolution.
==============================
Note added 22.VII.2015: As Scott Atran points out in the comments, the last sentence is too strong. But read the article by Azar Gat, which brings together numerous lines of evidence, making the case for war before civilization very convincing to me.
I’m inclined to favor Peter’s take but the quote and analysis of Wm Buckley regarding Australian aborigines can hardly be counted as “decisive.” Buckley left no first hand accounts, had divided loyalties and, in any event, no uncorroborated single source from long ago should be taken without a fistful of salt.
You are quite right, and the sentence you object to is too exuberant. Take a look at the article by Gat, if you haven’t done so yet. He does a very good job marshaling evidence form a variety of sources, and it’s very persuasive.
I suspect the decisive factor for this issue is the extent to which preagricultural groups found themselves occupying the same or adjoining space and competing for the same resources. This was less likely before agriculture, of course, but it did happen. It probably even happened much earlier, accounting for the disappearance of all the erectus cousins in Eurasia that sapiens happened to run into. Human nature goes way back, Rousseau notwithstandig.
I agree. It makes sense that during Pleistocene climatic chaos warfare flared up periodically. The glaciers melt, human groups colonize the new areas, and for a while population density is too low – it’s easier to move away from the aggressor. But then the landscape fills up, and that safety valve is gone.
And it’s not just erectus. There is Neanderthals. In fact, during the Pleistocene there were about 20 species of Homo, and there was one.
wonderful post, Peter… thank you v much. Can’t wait to read Gat’s book plus learn more about the who and what of Buckley.
Surely, the human propensity to aggression is based on the Y chromosome and explains why only males of the species do physical violence. It starts to kick in 2 months after fertilization of the fetus-to-be and plays out in his life in groups large and small after birth. He, individually and as an adult, has some (lots to little, arguably, depending …) control over its expression, but only he — as in human ♂ — has the potential.
The human ♀ by contrast (lacking the Y and its genes) doesn’t do physical violence at all. Her role is to connect and nurture both before and after birth.
These are mammalian traits that go back a couple of hundred million years. They were not hugely modified in the past few thousands of years when humans started to settle down. But their expression changed b/c the people were closer together and coveted others’ accumulated resources more strongly and had the means to control them themselves (not having to move every six months or so). Hence, larger scale, more prominent, etc. Stir in technological change re: weaponry and all of a sudden (!) it’s war!
Best to all,
L.
The gender with the Y chromosome is more inclined to violence as an option, yes, but that does not mean that the gender without the Y chromosome does not covet (or desire that which can be gained from violence).
Thanks, Lee. In case you cannot get the text of Gat’s article, the reference he uses for Buckley is this:
Morgan J. 1980. The life and adventures of William Buckley: thirty-two years a wanderer among the aborigines of the unexplored coun- try round Port Philip. Canberra: Australian National University Press.
//The human ♀ by contrast (lacking the Y and its genes) doesn’t do physical violence at all. Her role is to connect and nurture both before and after birth.//
of course you aren’t being strictly serious.
I completely disagree that violence is a male trait. and what’s it got to do with the Y chromosome? among other indicators, the hormone testosterone is a very strong indicator of tendency to aggressive behaviour. males have lots, but females also have natural level of testosterone.
aggression and competition is a predominantly male trait but it’s prevalence is normally distributed among males and females (such as the distribution of testosterone levels) with a small number of females at the right end of their distribution being more disposed to violence than the males at the left end of the male distribution.
https://www.youtube.com/watch?v=FdvAFCeOsGU
On the Y-chromosome: in any case, it doesn’t explain variation in violence between human societies, since they all have 50% of males.
I think a case can be made that warfare was unimportant in human affairs until after the last glacial maximum. The basic reason is that people seem to have been quite rare until after the last glacial maximum and exceedingly rare before that. Also, intergroup competition is not the only mechanism that might explain human cooperation. The Russian naturalist Peter Kropotkin observed that harsh environments can favor cooperation if cooperation is necessary to exploit that environment. Humans seem to have long used subsistence strategies like big game hunting that require cooperation and cooperative breeding is obligatory in humans because of the demands of our big brained highly altricial infants.
See my previous commentary: https://evolution-institute.org/commentary/peter-j-richerson-was-territoriality-important-in-the-pleistocene-a-commentary-on-johnson-and-toft/
On Kropotkin’s mechanism of selection see:
Smaldino, P. E., Schank, J. C., & McElreath, R. (2013). Increased costs of cooperation help cooperators in the long run. The American Naturalist, 4, 451-463.
I agree that during the Pleistocene intergroup competition often took the form of “games against nature”, which Sergey Gavrilets distinguishes from “us versus them games.” However, during the long periods of glacial maxima, human populations must have been compressed to some degree in regions suitable for human hanitation, and I think that conflict and between-group violence was inevitable.
Also, Sergey’s models show that us-versus-them games are more efficacious in selecting for cooperation than games against nature.
Peter, I read in a Marvin Harris book (namely in “Cows, pigs, wars and witches” when speaking about Chagnon findings) that the yanomamo bands don´t have 50% males. Those bands practice selective infanticide and thus biasing the gender ratio in favor of males. According to William T. Divale, who studied more tan 600 traditional populations, this ratio can reach up to 67:33 male-female ratio for children. This gender bias is not present in adult populations, what is evidence in favor of a higher mortality rate for adult males compared to females. Warfare is considered to be one of the main causes (since this gender bias is of no use in intragroup competition).
It is not crazy to assume that this cultural group trait enhances the band capacity for aggression: bands with a more biased male:female ratio would have an advantage over less gender-biased bands. In consequence gender-biased infanticide should be widespread among yanomamo bands, since weak bands would eventually dissapear absorbed by the more aggressive raiding bands… which are “hungry” for females and have more pounds of male muscle…
In my opinion this gender bias is the group analogous of individual Sexual Dimorphism. This way Sexual Dimorphism trascends the individual and becomes a group trait. As a matter of fact this cultural trait could constitute the most unarguable evidence of a PHENOTYPIC group adaptation due to between group competition. According to this “Sexual Dimorphism” analogy we could infer that cultures composed of groups with high male:female children ratio are subject to high levels of between group direct competition (warfare), what is analogous to the high male:female body size ratio that we see in species with higher levels of intrasexual competition.
By the way, females are the ones responsible for executing the gender-biased infanticide so there is nothing about the Y cromosome in this. Neither it is in the X cromosome. It is in the C cromosome: Culture.
Thank you, Juan. You make a valid point, and I stand corrected. This is one of the advantages of having a blog – I can experiment and get corrected when the experiment fails.
Now the observation about sex-selective infanticide immediately raises the question: what about China? Should we expect it to pursue a more aggressive policy now that it has substantially more young males than females?
Note that female infanticide had been practiced in China for a very long time and the guys at the top of the social pyramid tended to take plenty of concubines (who they were loathe to share out). This meant that having an unbalanced gender ratio was probably the norm in many regions throughout Chinese history.
However, I don’t think the aggressiveness of Chinese foreign policy was much affected by the internal gender ratio historically. Excess males (generally at the bottom of the pyramid) would lead to social strife and uprisings, however. Also, excess males would be more willing to strike out for frontier lands. Arguably, that was a cause of the Chinese diaspora in Southeast Asia (and also Han settlement of Taiwan and Hainan). These days, those frontier lands include Africa.
That was me.
Richard, I agree though I am not familiar with the demographic gender distribution in China along the ages.
As far as I know poor people from traditional societies (as in India) tend to favor a female gender bias (through selective infanticide) since girls constitute a more “conservative” reproductive investment than boys: girls imply assured profitability but limited earnings. On the other hand rich people tend to favor a male gender bias since rich sons are able to potentially sire an unlimited number of children.
In any case this conditional gender bias has nothing to do with the yanomamo-like male bias caused by between group competition. Now we are talking about a social class induced gender bias that could even cancel itself; More girls among poor people would compensate for more boys among rich people.
What i am trying to convey is that the yanomamo-like gender bias is a phenotypic group trait consequence of group selection and the group analogous to Sexual Dimorphism. On the other hand the Indian-like gender bias is consequence of internal social struggle among individuals and families.
Peter, the case of modern China seems very artificial to me. It is not the result of cumulative cultural evolution but the result of an arbitrary bith control policy. It is more similar to a mutation than to an adaptation.
Apatations are both cause and consequence. The current sex bias could be the cause of increased male aggresiveness but I think that that aggressiveness would be channeled more into internal fighting (and civil wars) than into expansionist warfare. It could even increase the probability of a revolution!… It depends on the levels of asabiya.