Yanomami Warfare: How Much Did Napoleon Chagnon Get Right?

Since most lethal conflicts among the Yanomamö involve disputes over women at some point in the development of the dispute, the status of unokai [killers] by definition is intimately related to reproductive striving - Napoleon Chagnon, The Yanomamo, 2012.

One of the most acrimonious debates in anthropology over the last few decades revolves around patterns of warfare among the Yanomami forager-horticulturalists of the Amazon. What began as a contentious, but scholarly debate in the late 1980’s/1990’s became a conflict over a variety of incendiary claims made in the book Darkness in El Dorado (2000) by author Patrick Tierney. The book and subsequent media attention ended up derailing what was otherwise a fairly informative discussion addressing the nature of warfare among Yanomami, and how those insights can be applied to other small-scale societies. Rather than relitigating the controversy over Tierney’s book, I want to go back to the scholarly debate between anthropologists Napoleon Chagnon, and his main critic, R. Brian Ferguson.

Chagnon initially gained controversy for his ideas about violence and warfare among the Yanomami – and the potential application of these ideas to small-scale societies more generally – arguing that “homicide, blood revenge, and warfare are manifestations of individual conflicts of interest over material and reproductive resources.” In particular, Chagnon noted that Yanomami men who had killed had greater reproductive success than men who hadn’t. Ferguson contested this claim, arguing that, among other things, this effect is primarily driven by the fact that killers are more likely to be older (older males have more children), and more likely to be a ‘headman’ (headmen usually have more wives and more children).

Regarding his objection about the inclusion of headmen in Chagnon’s sample, this seems like Ferguson is advocating a preferred form of post-treatment bias, by wanting to statistically control for a variable in order to dilute the size of an effect associated with it. 12 of the 13 headmen in Chagnon’s sample were killers (the only non-killer had only recently obtained headman status). If being a killer is, for all practical purposes, a requirement to obtain or keep headman status, then removing headmen from your sample just obscures the way killing can be a pathway to greater power and reproductive success.

Warriors in small-scale societies gaining greater status and marriage opportunities is a fairly common (though not universal) trend. I discussed aspects of this in two articles over at Quillette, and I also noted this pattern in my last blog post discussing head-hunting traditions across cultures, [edit: and see also my more recent commentary over at Behavioral and Brain Sciences with Luke Glowacki].

Table from 'The Role of Rewards in Motivating Participation in Simple Warfare' (2013) by Glowacki & Wrangham.

Two other objections Ferguson raised are worth mentioning. Ferguson noted that Chagnon could not account for dead men in his sample (maybe being a killer is associated with greater risk of death, and potentially worse reproductive success overall when including the dead, so only accounting for living men leaves you with a survivorship bias in your sample). This is a reasonable objection, although to my knowledge it hasn’t been adequately tested. It’s also not exactly fatal to Chagnon’s model; it would simply illustrate that being a killer, not unexpectedly, is a risky reproductive strategy, with potentially high-costs but large benefits for success. At larger social scales, you can see this with the examples of Ghengis Khan or Ismael the Bloodthirsty, that being a successful conqueror conferred some pretty substantial fitness benefits.

Although, as those examples show, political jockeying and developing coalitions of other men to be violent on your behalf, potentially reducing your own personal exposure to risky conflict when possible, is quite important, so the success of the headmen among the Yanomami is worth noting.

Further, we’d also expect some stabilizing influence on this type of aggressive behavior, as being indiscriminately violent, or conversely, being unable to defend yourself, are both unlikely to be particularly helpful strategies. Chagnon makes a related point in his reply to Ferguson, noting that, “Being excessively prone to lethal violence may not be an effective route to high reproductive success, but, statistically, men who engage in it with some moderation seem to do better reproductively than men who do not engage in it at all.”

This fits with anthropologist Luke Glowacki and primatologist Richard Wrangham’s work among the Nyangatom pastoralists of East Africa, where men who participated in more low-risk stealth raids had greater reproductive success, while men who participated in more high-risk large battle raids did not have greater reproductive success. Glowacki and Wrangham have also shown that intergroup violence in both chimpanzees and among nomadic hunter-gatherers is often undertaken tactically; aggressors are more likely to attack when they have a numerical advantage and can ambush outsiders who encroach on their territory. Indiscriminate use of violence is not favored, but the tactical use of violence can represent a biologically and/or culturally adaptive strategy. As Chagnon wrote regarding raiding parties among the Yanomami, “The objective of the raid is to kill one or more of the enemy and flee without being discovered.”

Ferguson’s second objection is his argument that the influx of Western goods exacerbated Yanomami violence. This is difficult to test but it would not surprise me if it is true. The Salesian missions in the region distributed thousands of machetes and axes to the Yanomami, and due to unequal distribution and competition for highly valued Western goods such as these, it doesn’t seem unlikely that this may have increased rates of violent conflict.

Much of Ferguson’s work throughout his career has been devoted to reinforcing the point that initial contact with outsiders (particularly Western societies) can exacerbate small-scale warfare, even if ultimately colonial authorities eventually end tribal wars. I cited Ferguson favorably on this point in my Quillette article on colonial contact. This doesn’t mean societies like the Yanomami did not wage war in the past, of course, but it is certainly possible the scale and scope of their war practices were at the high end of its distribution when ethnographers like Chagnon visited them.

On the other hand, Ferguson makes a pretty severe error in attributing essentially all Yanomami conflict to competition over Western goods. While the Yanomami themselves often said their raids were due to revenge or access to women or witchcraft accusations, Ferguson refuses to believe this, attributing everything to basic material factors. I’ll have some posts coming out in the future on traditions of bride capture, revenge raids, and sorcery across cultures, but suffice to say here that these traditions are very common the world over, and generally can’t be attributed to Western influence.

I think Ferguson is missing a pretty big part of the picture here, which Chagnon has highlighted in his own ethnographic work. As Chagnon wrote in his book on the Yanomami, “New wars usually develop when charges of sorcery are leveled against the members of a different group. Once raiding has begun between two villages, however, the raiders all hope to acquire women if the circumstances are such that they can flee without being discovered.”

More controversially, Ferguson also has claimed that Chagnon himself (wittingly or not) exacerbated warfare among the Yanomami. The American Anthropological Association attempted to investigate this question in the aftermath of the publication of Darkness in El Dorado and were unable to come to a determination on this, although they did note an example of Chagnon participating in an attempt at a peace agreement between hostile villages, at great risk to himself.

Tentatively, here are some of my conclusions from this debate:

Successful warriors, among the Yanomami and elsewhere, often do reap social and fitness benefits. Although this is not always going to be true, and excessively, indiscriminately violent males are probably unlikely to do well. Context is important.

The hypothesis that the influx of Western goods contributed to some sort of increase in rates of violent conflict among the Yanomami seems plausible, in my view. How big of an increase I cannot say.

There is no evidence that Chagnon himself exacerbated violent conflict among the Yanomami. Chagnon did give gifts of machetes and pots and other Western goods to the Yanomami groups he studied, so it is, however, possible he may have contributed to the general problem of competition for Western goods. The scale of his gift-giving is dwarfed by the activities of the Salesian missions, however. Ferguson also agrees with this, and argues that the Salesian missions had a much greater impact on Yanomami violence than Chagnon.

I think Chagnon broadly got a lot right. Many of the factors that seem to stimulate violent conflict among the Yanomami revolve around cultural traditions that have been incredibly common the world over, and pre-date Western contact, such as wife capture raids, sorcery accusations and revenge attacks. On the other hand, it seems plausible to me that the influx of highly desired Western goods, and their unequal distribution, due in particular to the activities of the Salesian missions, would add a new contributing source of violent conflict. This contact pre-dated Chagnon’s arrival and continued while he was there. Further, the Yanomami were not small bands of mobile hunter-gatherers; they lived in relatively large villages (sometimes upwards of 400) and practiced horticulture, in addition to hunting and gathering.

While some patterns of Yanomami warfare are informative when considering many other small-scale, and potentially even ancestral, human societies (particularly in relation to wife-capture, sorcery allegations, and revenge raids, which have been documented among quite a few mobile hunter-gatherer groups) the comparison should not be taken too far.

Head in Hands: Notes on the Extraction and Display of Human Heads

Removing the head of a victim, however repellent to Western sensibilities, was not simply an act of gloating triumphalism but was regarded as transferring certain spiritual or supernatural benefits to the head-taker – Ian Armit, Headhunting and the Body in Iron Age Europe, 2012.

Neolithic plastered skulls with shell pieces used as eyes, in situ. From the paper 'The Plastered Skulls and Other PPNB Finds from Yiftahel, Lower Galilee (Israel)' by Milevski et al. (2014), published in Plos One.

Many scholars have remarked on the impressive size and abilities of the human brain, but few have understood the otherworldly allure of the human head. The head is the focal point of social interaction in life – its center of attention is communicated through its eyes, meaning is conveyed by its facial expressions, and language is emitted from its mouth, heard by its ears and interpreted by its brain. In death, it may be no less important; often functioning as an object of veneration or a trophy to be secured by the enemies of its owner.

Evidence for the removal and likely ritual use of human heads goes far back in human history. At the Late Pleistocene (130,000 years ago) Neanderthal site of Krapina in Croatia, the remains of a Neanderthal skull were found with 35 cut marks on the frontal bone. While other fossil material at the site show possible evidence of cannibalism, this skull is unique in that the cut marks are located on a region with very little muscle tissue, and the parallel cuts would not have been useful in removing the scalp, making cannibalism or defleshing unlikely explanations. Anthropologist David Frayer and his colleagues argue that these cut marks represent, “some type of symbolic, perimortem manipulation of the deceased.”

The remains of skulls with cut marks similarly lacking a utilitarian function have been found at the early Neolithic (11,000 – 12,000 years ago) site of Göbekli Tepe in southeast Turkey. Archaeologist Julia Gresky and her colleagues described this find in relation to evidence for the existence of similar ‘skull cults’ that have been found throughout the region, writing that;

In the Pre-Pottery Neolithic [9,000 – 11,600 years ago] of Southeast Anatolia and the Levant, there is an abundance of archaeological evidence for the special status assigned to the human skull: In addition to the deposition of skulls in special places, as attested by the “skull depot” at Tell Qaramel or the “skull building” at Çayönü, human skulls are also known to have been decorated, for example, where the soft tissue and facial features have been remodeled in plaster and/or color was applied to the bone.

Archaeological finds from all over the world attest to the enduring fascination humans have had with skulls. At Gough’s Cave in England, the remains of skull caps, plausibly used as drinking cups, were found dating back to about 15,000 years ago.

Various archaeological and ethnographic examples of human bone modification. From the paper 'Modified human crania from Göbekli Tepe provide evidence for a new form of Neolithic skull cult' by Gresky et al. (2017), published in Science.

The earliest evidence for decapitation in the Americas goes back to about 9,000 years ago in Brazil, where a skull was found buried with amputated hands carefully laid over the face.

9,000 year old skull with amputated hands placed over the face. From the paper 'The Oldest Case of Decapitation in the New World (Lapa do Santo, East-Central Brazil)' by Strauss et al. (2015), published in Plos One

The practice of extracting the heads of enemies is also well-attested to among a diverse array of societies described in ancient literature. Decapitation is mentioned numerous times in the Bible, such as when David cut off the Philistine Goliath’s head, brought it back to Jerusalem, and showed it to King Saul (1 Samuel 17:54), which is later mirrored by the Philistines cutting off King Saul’s head and publicizing his death among their own people (1 Samuel 31:9). There is also the famous example of Salome’s demand to King Herod that he bring her the head of John the Baptist on a platter (Matthew 14:8).

Salome with the Head of John the Baptist (c. 1607) by Caravaggio

Ancient Assyrian inscriptions contain numerous accounts of kings decapitating the heads of enemies. King Ashurnasirpal II (883–859 BC) boasted, “I gouged out the eyes of many troops. I made one pile of the living [and] one of heads. I hung their heads on trees around the city.” His son, King Shalmaneser III (859–824 BC) claimed, “I mustered (my) chariots and troops. I entered the pass of the land Simesi (and) captured the city Aridu, the fortified city of Ninnu. I erected a tower of heads in front of the city. I burned ten cities in its environs.”

Wall decoration depicting Assyrian warriors carrying severed heads during the siege at Lachish (8th-7th century BC). From the British Museum; photo by Ferrell Jenkins.

The Greco-Roman writer Plutarch described how the Parthians cut off the Roman soldier Publius’s head, attached it to a spear, and displayed it in front of his father, the Roman general Crassus. A Parthian soldier would later cut off Crassus’s own head, which was then brought to the Parthian King Hyrodes, while he was watching the play The Bacchae by Euripides, which itself contains a plot involving a decapitation and the display of a head.

The Greek writer Strabo, in his work Geography, described the practice of headhunting among the Celts, writing that;

In addition to their witlessness, there is also that custom, barbarous and exotic, which attends most of the northern tribes — I mean the fact that when they [the Celts] depart from the battle they hang the heads of their enemies from the necks of their horses, and, when they have brought them home, nail the spectacle to the entrances of their homes.

Celtic headhunting is particularly well-documented among classical sources.

Table noting various classical sources that describe Celtic headhunting. From Headhunting and the Body in Iron Age Europe (2012), by Ian Armit.

While many early archaeological finds point to unknown ritual use of human heads, much of the ancient literature described here involves more practical matters, such as cutting off the head of a hated enemy to offer proof of his death, or publicly displaying decapitated heads to humiliate or terrify rivals. Among more recently documented traditional societies, both the signalling function of headhunting in warfare, as well as the sacred role of the head in ritual life, were described by late nineteenth and early twentieth century ethnographers.

In 1922, anthropologist Ivor Evans described multiple reasons for head-hunting among various societies in Borneo, writing that;

The reasons for head-hunting among Bornean tribes in general seem to have been threefold: firstly, the practice was not without religious significance; secondly, it was considered a sport and the heads regarded as trophies; and thirdly, among some tribes no youth was considered fit to rank as a man until he had obtained a head, the women taunting those who had been unsuccessful as cowards. (Evans, 186)

A similar pattern was identified among societies on the island of Kiwai in New Guinea in 1903 by missionary James Chalmers, who wrote that, “When heads are brought home, the muscle behind the ear is given in sago to lads to eat that they may be strong…The skull is secured, and the more skulls, the greater the honour. No young man could marry, as no woman would have him, without skulls.”

In his volume on Head-hunters (1901), ethnologist Alfred Haddon wrote that, “There can be little doubt that one of the chief incentives to procure heads was to please the women.” In these societies, capturing the heads of enemies is associated with masculine virility, and a young man must seize the skulls of outsiders to be considered a viable partner for a young woman.

The collection and control of heads was considered a source of prestige and power in some societies. In 1896, anthropologist Henry Ling Roth wrote that among the Iban people of Borneo;

…the most valuable ornament in the ruai [veranda] by far is of course the bunch of human heads which hangs over the fireplace like a bunch of fruit; these are the heads obtained on various warpaths by various members of the family, dead and living, and are handed down from father to son as the most precious heir-looms… (Roth, 13)

In The Evolution of War (1929), sociologist Maurice R. Davie further stresses the relationship between headhunting and prestige, adding that, “In Borneo the possession of a large number of heads is also a qualification for the chieftainship, and certain feasts can only be held by a war leader who has been particularly successful against the enemy and has succeeded in taking many heads.” Davie describes a ceremony celebrating a successful headhunter among the Iban people of Borneo, recounting how;

the women, singing a monotonous chant, surround the hero who has killed the enemy and lead him to the house. He is seated in a place of honour, and the head [the trophy he has taken] is put on a brass tray before him, and all crowd around to hear his account of the battle, and how he succeeded in killing one of their foes and bringing home his head. (Davie, 52)

In the recent volume Emergent Warfare In Our Evolutionary Past (2018), anthropologists Nam. C. Kim and Marc Kissel describe a number of traditional headhunting practices, explaining the pattern commonly found across cultures; “For many societies, a warrior’s prestige or spiritual power could be increased depending on the reputation of a defeated adversary, and often the head served as a personal manifestation of that enemy. Such trophies could symbolize a warrior’s prowess and courage.”

Ifugao warrior showing the heads he has taken from his enemies. From The Head Hunters of Northern Luzon (1912) by Cornelis Wilcox.

The reputational effect of being a successful headhunter is often connected to religious notions of warriors capturing the souls of defeated enemies by extracting their heads. Davie notes that, “Another religious motive leading to head-hunting is the belief that the slain become slaves to the victor in the next world. This notion is an incentive to warlike prowess among the Nigerian head-hunters.”

In some cases, these captured souls provide the warrior with protection or spiritual power. For example, among the Jivaro of Peru, anthropologist Michael Harner wrote that, “A man who has killed repeatedly, called kakuram or “powerful one,” is rarely attacked because his enemies feel that the protection provided him by his constantly replaced souls would make any assassination attempt against him fruitless.”

After extraction, heads were often treated to a range of modifications, primarily for long-term preservation or decoration.  In the volume Violence and Warfare among Hunter-Gatherers (2016), anthropologist Paul Roscoe described headhunting practices among New Guinea foragers, writing that, “Headhunting raids were sometimes overnight affairs, launched usually on foot, though occasionally by canoe. The heads were brought back to be modeled, painted, and stored as trophies to be used in future "ritual preparation for warfare.””

In 1894, missionary Philip Walsh described a complex treatment process for heads among the Maori, writing that;

All authorities agree in stating that the brain, tongue, eyes, and as much as possible of the flesh were carefully extracted; the various cavities of the skull, nostrils, &c., stuffed with dressed flax; and the skin of the neck drawn together like the mouth of a purse, an aperture being left large enough to admit the hand. The lips were sometimes stitched together, and the eyes were invariably closed, as the Maoris feared they would be bewitched (makutu) if they looked into the empty sockets. This was done by a couple of hairs attached to the upper lids, and tied together under the chin.* The head was then subjected to a steaming process, which was continued until all remains of fat and the natural juices had exuded. Rutherford states that this was done by wrapping it in green leaves, and submitting it to the heat, of the fire. Polack says it was steamed in a native oven similar to that used for food. Those seen by Mr. King were impaled on upright sticks set in open holes in the ground, which were kept supplied with hot stones from a fire close by, while the operator basted them with melted fat.† Each of these processes would equally serve the purpose required. The next stage was a thorough desiccation, effected by alternate exposure to the rays of the sun and the fumes of a wood fire, of which the pyroligneous acid helped to preserve the tissues and protect them from the ravages of insects. A finishing touch was given by anointing the head with oil, and combing back the hair into a knot on the top, which was ornamented with feathers, those of the albatros being usually preferred. The work was then complete.

The extraction and display of heads is not always directly connected to violence or warfare. In Headhunting and the Body in Iron Age Europe (2012), anthropologist Ian Armit writes that, “In a number of ethnographically documented contexts, certain communities retain, display, and venerate the heads of their own kin.” Armit adds that;

These are obtained not through violence but in the course of conventional funerary practices, even if only a small proportion of heads are retained. These may belong to particularly important, influential, or unusual individuals, whose particular life histories made them appropriate foci for communal ritual and memory, but equally they may be chosen quite arbitrarily. Among the Mountain Ok peoples of Inner New Guinea, for example, skulls were displayed in central ‘ancestor houses’ where they were painted, on certain occasions, in the colours of particular clans and played a central role in communal ceremonies. (Armit, 12).

Headhunting is sometimes considered essential to maintaining a thriving, productive society. Armit writes that, “the explanation most commonly offered by practitioners themselves, was that headhunting was necessary to ensure and enhance the fertility of crops, people, and animals.” This connection was made explicit among some societies in Borneo, with the traditional practice of “treating infertile women by placing a trophy head between their thighs.”

In some cases, the heads are viewed as essentially living things, requiring continued sustenance and care. Among the Berawan of Borneo, heads had to be “fed” with offerings, and “kept warm with a fire that never went out.” Anthropologist Peter Metcalf writes that, in 1956, the Berawan lost a number of the skulls they kept in an accidental fire. However, the loss was not lamented, as “Though it was claimed that the heads had the potential to bring benefits to the community, the service of them was considered onerous.”

The recognition that the extraction and display of human heads is not a singular phenomenon, but instead can stem from multiple diverse motivations helps pin down why these practices are quite variable, yet still widespread across cultures. Headhunting can be incorporated into cultural practices of warfare, and used to indicate a society’s strength and power in intergroup conflict. The care and decoration of heads can also be an important part of a society's religious beliefs or practices of ancestor worship.

Human heads, disconnected from their formerly living bodies, have been used variously to terrify enemies, secure status and prestige for an individual and their kin, or honor the dead. Whether religious or secular, the display of human heads has been a relatively common component of human cultural traditions across cultures and throughout history.

The Dilemma of the Deserted Husband (and why polygyny is more common than polyandry)

In the volume Politics and history in band societies (1982), anthropologist George Silberbauer described how a G/wi forager band in the Central Kalahari Desert solved a social problem involving a man named /wikhwema.

/wikhwema was “not very bright”. Silberbauer described him as a vain and inflexible man, prone to petulant outbursts, whose opinions were often wrong. He was apparently considered something of a standing joke within the band. Unsurprisingly, his wife N!anoag//ei was described as a morose and chronically dissatisfied woman, and one day she left /wikhwema for his best friend, a recently widowed man named /amg//ao.

/amg//ao was well-regarded within the band. He was “a virtuoso dancer, a consistently successful hunter and was rumoured to be a bit of a demon as a lover.”

/amg//ao was also a dwarf.

/wikhwema mourned the loss of his wife and best friend for over a year, and many in the band considered him quite the nuisance, including his daughter and mother-in-law, who still lived in the band. Every time /wikhwema was despondent or threw a tantrum, the rest of the band would convene to discuss the problem. Eventually, word got around to where N!anoag//ei and /amg//ao were living, and intervening parties tried to convince her to return to /wikhwema, but she wouldn’t budge.

While N!anoag//ei was happy with /amg//ao, she missed her daughter and mother terribly, and wished to see them again.

Finally, some “lateral thinker” among the band proposed a unique solution. How about a joint marriage: N!anoag//ei, /wikhwema, and /amg//ao could all live together. A polyandrous marriage! Polyandry was completely unknown to the G/wi, yet after a long deliberation among the band, this arrangement was considered acceptable.

While the trio did not exactly live happily ever after, /wikhwema was no longer considered a nuisance to the rest of the band, and the matter was considered resolved.

Among the G/wi, this is the only known example of a polyandrous marriage. Most marriages among the G/wi are monogamous, however, there were nine men married polygynously: eight men with two wives each, and one man with four wives.

Across cultures, polygyny is significantly more common than polyandry. In the Ethnographic Atlas, less than 1% of societies (only 4 out of 1231) are coded as practicing polyandry, while 85% (1041 out of 1231) of societies are coded as practicing at least occasional polygyny. In anthropologists Katherine E. Starkweather and Raymond Hames 2012 paper ‘A Survey of Non-Classical Polyandry’, published in Human Nature, they argue that polyandry is more common than previously reported, noting there is evidence for at least occasional polyandry in an additional 53 societies.

However, as with the G/wi foragers, polyandry still tends to be rare, and generally restricted to specific social and ecological circumstances. For some of the societies mentioned by Starkweather & Hames, there is only a single example of polyandrous marriage, such as among the !Kung, and as we saw among the G/wi. Further, polyandry in many societies may be a temporary response to a highly skewed sex ratio in favor of men. For example, Starkweather & Hames write that, “10 of 15 marriages were polyandrous in 1958 among the Shirishana Yanomamö when the sex ratio was 149 [149 men for every 100 women]. As the population grew and the sex ratio declined to 108, however, only 1 of 37 marriages were polyandrous.”

Overall, polyandry is more likely to occur in these contexts:

1) Where the sex ratio is highly skewed, with significantly more males than females.

2) Among relatively ‘egalitarian’ hunter-gatherer societies.

3) Where adult male mortality is high.

4) Among brothers.

5) Where males generally contribute a majority of the subsistence and economic labor.

6) Where males are often absent for prolonged periods of time (frequently traveling to trade, for example).

Table from 'A Survey of Non-Classical Polyandry' (2012) by Starkweather & Hames illustrating the factors most commonly associated with polyandry.

Starkweather & Hames note that, among the most well-known societies practicing polyandry, such as those found in Tibet, polyandry occurs, “where land is scarce and a fundamental requirement for successful reproduction and the maintenance of high status,” and therefore, “the marriage of all brothers in a family to the same wife allows plots of family-owned land to remain intact and undivided.”

For the 53 cases of polyandry reviewed by Starkweather & Hames, polyandry generally seems to be a reproductive strategy mostly used by lower status males, likely as a last resort. They write that, “less socially competitive males may be willing to share a wife and make an attempt at achieving paternity, rather than risk never reproducing.”

Among various Inuit societies, “Exceptionally great hunters are able to support more than one wife; good hunters can support one wife; and mediocre hunters, or those unwilling or unable to take a wife from another man, share a wife.” As we can see, polygyny and polyandry can co-occur, and where some competent, high-status males are able to support multiple wives, lower-status males may end up having to share, or risk having no wife at all.

In such contexts, women can also benefit from multiple partners, gaining protection and provisioning from their additional husband(s), particularly when their first husband is likely to die early or be absent for long periods of time.

Overall, polygyny being more common across cultures than polyandry is not at all surprising considering patterns of sexual dimorphism in humans, and their implications for sexual selection during our evolutionary history. I have previously described how sex differences in gamete production can help explain why men, across cultures, are more violent, and more prone to take political power, than women are. The same basic explanation follows here. All else being equal, because of basic sex differences in gamete production, which contribute to sex differences in reproductive output and parental investment, an individual male generally has more to gain from mating with multiple partners than an individual female does. And further, an individual male likely faces a greater cost to his reproductive success by sharing a mate than an individual female does.

On average, polygyny benefits a given male more than polyandry benefits a given female, and polyandry hurts a given male more than polygyny hurts a given female.

Note that I am not saying men and women are ‘wired’ to behave in a specific and narrow way. Because of sex differences in reproductive strategies, we would expect that men would, on average, be less wiling to share a mate than women would be. But as the cases of polyandry discussed above show, in certain socioecological circumstances we can expect some males — particularly lower-status males — to be equally or even more likely to share than the average female, depending on factors such as the sex-ratio, mortality profile, and subsistence practices, as they may have no opportunity to reproduce otherwise.

[See also my articles on monogamy and polygyny.]

The sad and violent history of 'peaceful societies'

“...war is almost ubiquitous in the ethnographic record, in the absence of external powers that imposed pacification, and the frequency distribution is skewed sharply towards the high end.” - Ember & Ember (1997)

Semai man wearing the Shamanic Headman's Dress. "The blowpipe and dart quiver are emblems of Semai identity." - From Overwhelming Terror (2008) by Robert Dentan

Over at the Department of Anthropology web portal on the University of Alabama at Birmingham website, there is a section on ‘Peaceful Societies’, with an ‘encyclopedia’ listing 25 putatively peaceful societies. The page is clearly influenced by the work of Douglas Fry, who is the chair of the anthropology department at UAB, and, fittingly, two of his books are recommended on the ‘Best Books’ section of the site. Along with links to ‘News and Reviews’, and the ‘Peaceful Societies’ facebook page, there are two motivational quotes displayed on every page:

“RESPECT FOR THE RIGHTS OF OTHERS IS PEACE” -Benito Juarez

and,

 “ANYTHING THAT EXISTS IS POSSIBLE” – Kenneth Boulding.

Aspiring to make the world a more peaceful place seems like a worthwhile goal to me. To that end, one would think that seeking out societies that have solved the problem of violence, and thus may be worthy of emulation, would be a productive endeavor. For each of the societies referenced, the website attributes their seemingly low rates of violence to social norms discouraging violent behavior, and traditional practices of peaceful conflict resolution.

Unfortunately, I think there is a very important factor being left out.

In addition to the fact that some of these populations had higher rates of recorded violence in the ethnographic past, many of the ‘peaceful societies’ mentioned have a long history of being violently subjugated and enslaved by more powerful neighboring societies.

Consider the G/wi foragers of the Kalahari Desert. The ‘Peaceful Societies’ page cites Hunter and Habitat in the Central Kalahari Desert (1981) by George B. Silberbauer as the “major book on the G/wi”. In that book, Silberbauer describes the G/wi as “a timid people, fearful and initially shy and reserved in the presence of strangers.” This is perhaps unsurprising considering the history of violent interactions with neighboring groups that Silberbauer describes;

John Campbell, who visited the southern Tswana in 1813 and 1820 describes Bushman [G/wi] raids on his hosts’ cattle as if they were of fairly frequent occurrence. Retaliation ranged from giving the reivers a severe thrashing to the indiscriminate slaughter of men, women, or children encountered by the punitive party. Missionaries and travlers who worked among and visited the Tswana in the second half of the last century report them as keeping Bushman slaves. Mackenzie, writing in 1870, said that the slaves were absolute property…He makes it clear that both the Tswana and the Kgalagari despised Bushman and treated them very badly at times. (Silberbauer 7)

In addition to violent conflict with various neighboring native African societies, Silberbauer also describes extensive violent interactions with Dutch, German, and British farmers during the 19th century, with the killing going both ways. In the 1970’s anthropologist Mathias Guenther noted that many Bushmen living in the same district as the G/wi began to refer to themselves as the 'kamka kwe, which in the Naro language means ‘weak or inconsequential people', comparing themselves unfavorably to more powerful neighboring societies.

A scarred G/wi woman. From Hunter and Habitat in the Central Kalahari Desert (1981) by George B. Silberbauer

Another society on the list, the Batek of Malaysia, has a similar history. I previously referred to the Batek in an article I wrote for Quillette about contemporary hunter-gatherer societies. Quoting myself here:

…the Batek of Malaysia…have a long history of being violently attacked and enslaved by neighboring groups, and developed a survival tactic of running away and studiously avoiding conflict. Yet even they recount tales of wars in the past, where their shamans would shoot enemies with blowpipes.

While the ‘Peaceful Societies’ page for the Semai of Malaysia is focused primarily on their methods of conflict avoidance, a link to one of the cited sources mentions how the Semai, “raise their children to fear strangers with stories of violence. The Semai have been dominated and enslaved by their neighbors, the more powerful Malay people, for centuries.” In anthropologist Robert Dentan’s book about the Semai, titled Overwhelming Terror (2008), he writes that, “The slave raids, unpredictable and brutal, create a sense that the whole cosmos is unpredictable and brutal. As in the Semai case, they may give rise to feelings that love and peace within the local group are the only security people can have.”

For the Mbuti, their ‘Peaceful Societies’ page draws on Colin Turnbull’s ethnographic works The Forest People (1961) and the aptly titled Wayward Servants (1965). These works describe the “submissive” relationship the Mbuti pygmies have with their neighboring Bantu village “masters”. While these works contain many charming descriptions of Mbuti individuals exercising personal agency and controlling their own destiny, and while Turnbull rejects any use of the term “slavery” to describe the Mbuti relationship with the neighboring villagers, the social system portrayed may be fairly described as one of servitude and dependency. In Wayward Servants, Turnbull writes,

As a child an Mbuti may grow accustomed to a number of "owners," as his parents move from band to band, or village to village. When he is old enough to hunt he will choose whichever "owner" happens to be convenient at the time, but if he does not get the treatment he expects, he will without hesitation get himself "adopted" by another villager, even in the same village. (Turnbull 47)

I have not given a detailed reading of the ethnographic literature for every society listed on the ‘Peaceful Societies’ page, but my impression is that many of these societies are ‘peaceful’ because they have been ‘pacified’ by more powerful neighboring societies. Many anthropologists have previously remarked on this pattern. As Lawrence Keeley wrote in his volume War Before Civilization (1996), "Most of these peaceful societies were recently defeated refugees living in isolation, lived under a "king's peace" enforced by a modern state, or both."

Table from Wrangham & Glowacki (2012) illustrating that many of the societies characterized by Fry as peaceful have a history of warfare in the past and/or neighbor more numerically and technologically powerful societies.

Many of the societies on the UAB 'Peaceful Societies' list have a sad and traumatic history of being killed, exploited and enslaved. Highlighting these societies as paragons of peace – alongside motivational quotes – as though their situations are something to aspire to, seems to me completely inappropriate.