Human behavior over the ages

By Razib Khan | January 7, 2012 2:49 pm

Over at Scientific American Eric Michael Johnson has a very long post up, The Case of the Missing Polygamists. It is a re-post of something he already published at Psychology Today a few years ago. Though provisionally a review of Sex at Dawn, Johnson covers a lot of ground, and also has extensive quotations from Sarah Blaffer Hrdy.

I’m reflecting upon the post for a second time because it is very rich in ideas, and lays out may different general concepts and specific propositions. The bottom line from what I can gather is that Johnson agrees with those thinkers who believe that agriculture and the Neolithic revolution to a great extent reshaped social relations, and give us a skewed perception of “normal” human societies. I’m not going to rehash all of the points in the piece, but will focus on just a few which I think I can extend upon fruitfully.

Long time readers of this weblog know that I tend to accept that something radical shifted during the Neolithic revolution. I’m of the opinion that like most animals humanity’s state was Malthusian during the age of hunter-gatherers, and of farmers. That is, gains in population eventually absorbed productivity increases due to technology (e.g., bow and arrow) or surplus land (e.g., settlement of the New World by humans). But different forms of Malthusianism can obtain different stable states. The rhythm of life of a Chinese peasant and a Bushmen are very different, despite the fact that both may operate on the Malthusian subsistence margin. Malthusianism is a end point, it does not specify the dynamic by which one proceeds toward it.

Johnson relays the idea that prior to agriculture humanity had a matrifocal and de facto polyamorous bias. For the purposes of my thought here we need to separate the social and biological. In the social sense matrifocality simply means that males move between focal groups, while females remain in their natal groups. Polyamory implies that males and females may have multiple sexual relationships. In a genetic sense matrifocality should imply that Y chromosomes flow between groups (lower Fst), and mitochondrial lineages exhibit greater geographical constraint (higher Fst). In the longer term equitable pure polyamory would not be genetically distinguishable from pure equitable momogamy (because of more combinations in the former case there may be more diverse autosomal haplotypes, but I’m not sure this is very relevant for this discussion).

It isn’t innovative or surprising for someone to assert that agriculture was a major rupture in human history. Major public intellectuals routinely take a shot at characterizing what made it so special, and it’s a lively area of scholarship. Rather, I will reiterate here what I have held for many years: the “traditional” and normative social systems common among civilized societies since the rise of agriculture and the emergence of mass society are cultural adaptations which serve to constrain impulses which are deeply hard-wired within our species. Elite lineages the world over arranged the pair bonds of their offspring for many generations, and yet this often meets resistance, or at least resignation. The tales of adulterous lovers subject to a tragic fate are common literary motifs. This is I suspect an aspect of evoked culture, the inevitable tension between our deep impulses driven by individual preferences, and the social obligations which many have to had fulfill as part of extended kinship networks which had accrued prestige and capital. Both of these are human universals, as are the consequences. The high culture literature records this tension, and elaborates upon it so as to model proper and correct behavior for elites so as to avoid tragedy.

I have no doubt that hunter-gatherer societies had lineages which accrued prestige and capital. The modern hunter-gatherer societies which Eric Michael Johnson highlights are not representative of the human past. They have been relegated to marginal land. In the past hunter-gatherer societies drew upon lands with greater primary productivity, so the chasm between themselves and their farming successors in terms of physical capital and social stratification was often less than we may expect using the modern relics as references. But, agriculture clearly signaled a shift in scale and quantity. Super-male lineages, such as that of Genghis Khan, are possible only due to the contingent conditions of civilization, in particular all the elements necessary for globalism. Agriculture was likely an amplification of a “winner take all” dynamic in the game of social positioning. And not surprisingly these societies also developed complex belief systems and institutions to moderate and dampen these tendencies, likely due to their innate instabilities, as well as a human bias toward egalitarianism (i.e., land redistribution and opposition to inequality is a tendency in many societies at the commanding heights, while world religions all exhibit an anti-Nietzschean bent, for lack of a better term).

The reason that “Western culture” with its individualist ethos is so attractive, and threatening, is that in many ways it is a purer reflection of the impulses which were operative in the ancestral environment. I am not here talking about the most extreme manifestations of Western liberality in sexual mores, such as gay marriage or formal polyamory (most people do not crave homosexual relations). Rather, a modicum of personal choice and sexual egalitarianism, are out of keeping with the norms which were necessary to maintain social order in the period between small-scale hunter-gatherer societies and the rise of the mass consumer society. On the margins of subsistence in a world of farmers individual action may redound very negatively upon the broader kinship group, so personal norms of honor and propriety may be highly developed.

And yet if these cultural norms were so strong why did humans not evolve their way out of their hunter-gatherer ethos? There are two primary reasons for this. First, for much of human history the norms outlined in high culture texts and religions were applicable only to elite lineages. This is history recorded in the texts, but it may not be most of lived human history. For example, religious marriages in much of medieval Europe were obligate for noble families, but may not have been for peasants, who made recourse to common law relationships. Bastardy is less of a concern in scenarios where property divisions are of no consequence. There’s no property to inherit. But, this phenomenon is probably moderated by the fact that over much of history elite lineages may have been more fecund than the masses. Lived history may be more ephemeral than we realize in a genetic sense.

A second explanation though is that the very tendencies which make adherence to traditional norms somewhat discomforting on an individual level are necessary in other contexts. Love is an inconvenience when it comes to arranging marriages for your offspring optimally on a social dimension, but it may be necessary for men and women to invest in their offspring due to the love they feel for them so that they live and flourish. In other words, psychological impulses which were inconvenient in one domain were necessary and adaptive on others. Phenotypically I’m implying that there was functional constraint, and genetically it would manifest as pleiotropy. I suspect that a strong tendency toward developing loving bonds with children is a much more important characteristic in these elite lineages than dampening the initial discomfort that may occur when one is paired off with someone with whom one is not particularly enamoured. In a social and biological evolutionary sense romantic love is less important than we might think in our individualist age. But, romantic love remains hard-wired within us because it is biologically impossible to suppress its manifestation so long as we need the emotion of love more importantly to bind us together with children.

Finally, let’s go back to Johnson’s treatment of the disjunction between idealized polyamory and realized polygyny in the ancient environment (at least to a mild extent). By this, he points to the reality that some of the Y chromosomal data point to a reproductive skew, where a few males tend to give rise to a disproportionate number in the next generation. In extreme polygyny you have a Genghis Khan situation, where males of one narrow lineage have an enormous reproductive advantage. The scenario sketched out in Johnson’s post is that females may have had relationships with several males (and the inverse), but there was a tendency toward favoring reproduction with one focal male or female. This does not seem to negate the reality of jealousy and drama. We see this among common chimpanzees, who have a classic mating system in the extreme sense outlined by Johnson (this species has huge testicles to generate viscous sperm the competition is so extreme). And modern polygamorists who have formal relationships all tell tales of enormous time investments necessary to maintain proper relationship equilibrium. This is I think the reason that elite lineages in mass agricultural societies turned toward simpler relationship networks. The older model was simply not sufficiently stable for the purposes of maintaining the social and cultural systems necessary for the proper functioning of the older Malthusian civilizations. This is evident when conflicts within elite lineages are often rooted in questions of paternity and maternity (half siblings; Charles Martel was the bastard son of his father, who superseded the legitimate line), or accusations of false paternity (the first Chinese Emperor was subject to this rumors due to his bad reputation in later generations).

Where does this lead us? I think it’s complicated. Many social conservatives would argue that you can’t just dispense with the whole cultural toolkit which has organically evolved over the last 10,000 years, and revert back to the more primal state of affairs before agriculture. Social liberals point out that the forms of the past are no longer necessary in the present. But though affluence has removed many necessary social constraints, we have not warped ourselves back to the Paleolithic either. The balance between our instincts, which evolved in small groups thousands of years ago, and our notional cultural mores, which crystallized during the Axial Age, is still a work in progress. I believe that the world religions were version 1.0 in regards to formalizing workable compromises between our basic natures and the realities of the aristocratic world. What we need is a version 2.0, where we balance the needs of the common person on the street, with their basic impulses. The great compromise between our biology and our current social complexity will continue. But it is a dynamic parameter, not a static element.

  • Razib Khan

    note: i did not address the issue of human variation. this is very important, but a huge topic. just as some people are naturally homosexual, some people are probably naturally monogamous while others are polyamorous. the modal human is probably in between, but current cultural norms tend to confuse modal with universal. explicit and open concurrent polyamory is common in the less wrong community. in fact, my own personal impression is that adherence to monogamy as a personal preference is a somewhat dissenting position which you would need to justify on rational grounds in the core of the community.

  • Wulf Kurtoglu

    Interesting point about romantic love being an echo of the love of parent for child. I can’t find the reference, I’m afraid, but I think I’ve seen something by Desmond Morris on this subject – pointing out that physical closeness is natural between parents and children, with the cuddling of lovers being a reversion to this, rather than the creepy quasi-original of it that our fear of pedophilia has made it.

  • Jason Malloy

    Data from genetics, anatomy, and anthropology suggest that for most of our evolutionary history humans were mildly polygynous. Johnson cites the Hammer study, but a more recent study found:

    “For the HapMap populations, we obtained β of 1.4 in the Yoruba from West Africa, 1.3 in Europeans, and 1.1 in East Asian samples. These values are consistent with a high prevalence of monogamy and limited polygyny in human populations.”

    Johnson also repeats the finding that 982 out of 1157 societies practice polygyny without the equally important qualifier, that most of the people within these societies do not practice polygyny.

    This larger pattern is the same for foragers; to quote leading forager expert Frank Marlowe:

    “The mean percentage of polygynous women is 20%… and for polygynous men, it is 12%…The mean percentage of single men is 11%… The majority of foraging societies are slightly polygynous… Although exclusively monogamous societies are rare, the majority of marriages within all but the most polygynous societies are monogamous

  • Razib Khan

    #3, i’m frankly a little on the skeptical side about the genetic findings. they’re not as clear as they should be. though i think mild polygyny (in a genetic sense) is the highest probability state. i keep track of this literature, and it isn’t moving as uni-directionally as it should. one citation in either direction isn’t too persuasive at this point. sex based size difference is the most important datum for me. that’s not as sensitive to a lot of parameters as the statistical genetic stuff.

    also, do you mean polygamy? women can’t be polygynous unless you’re talking lesbianism. [update: i think i understand what is meant now, never mind]

    all the talk about definitions is kind of useless too. we should just quantify by reproductive skew and present that as a summary statistic (we can define a cut off for what’s monogamous vs. polygynous). but as i said above the genetic results are not as informative about the past as i’d like (or at least the tests aren’t as sensitive and data sets not large enough).

  • Jason Malloy

    “Polygynous women” is part of a quote, though I would’ve expressed it similarly: women mated to men who have other female mates.

    One more minor thing: “The modern hunter-gatherer societies which Eric Michael Johnson highlights are not representative of the human past. They have been relegated to marginal land. In the past hunter-gatherer societies drew upon lands with greater primary productivity”

    This is a frequently made claim (I saw it most recently in Pinker’s Better Angels), however Frank Marlowe also tested this, and found it not strictly true:

    “To test if forager habitats are marginal we can compare them to the habitats of agriculturalists using the Standard Cross-Cultural Sample… Net primary productivity (NPP) measures yearly plant growth and can be calculated from satellite data… Using NPP, we find that indeed there is a lower habitat quality among the 36 foragers than the 150 agriculturalists. However, when we exclude those societies in colder climates… there is no difference in NPP… Warm-climate forager habitats are not less productive than those of agricultural societies in this sample”

  • Razib Khan

    #5, yeah, nice paper. though he does admit that It excludes animal biomass and includes
    inedible plant parts, so it is not an ideal measure of food abundance for humans. For example, rainforests contain less human food per kilogram of primary biomass than savannas do, but because there are so many more kg/m2 of primary biomass in rainforests there is usually more total food energy present.

  • Jason Malloy

    “Not strictly true” went too far. Rather Marlowe provides some data and reasons to be skeptical about the marginal land assumption (It’s always nice to see someone apply data to a conclusion widely taken for granted.)

    Johnson: “Therefore, the larger numbers of patrilocal (and polygynous) societies today is likely the consequence of agriculture and not a true reflection of the human past”

    By the way, one more important fact to highlight from the linked Marlowe papers is that polygyny rates are the same for agriculturalists and foragers, which undercuts what Johnson is arguing based on the Hammer paper.

    What’s more striking is that the major factors that influence monogamy (pathogen stress and male provisioning) are similar for foragers and agriculturalists.

  • Razib Khan

    By the way, one more important fact to highlight from the linked Marlowe papers is that polygyny rates are the same for agriculturalists and foragers, which undercuts what Johnson is arguing based on the Hammer paper

    i assume that the biggest difference is the magnitude of ‘super-male’ lineages.

  • Victor Grauer

    “The modern hunter-gatherer societies which Eric Michael Johnson highlights are not representative of the human past.”

    While this is certainly true, it is also somewhat misleading. According to my research, we can in fact isolate certain aspects of the culture of certain hunter-gatherer populations as representative of the culture of our Most Recent Common Ancestors in Africa. At least provisionally. And we can formulate falsifiable hypotheses on this basis. Thus, while no one contemporary indigenous group can be singled out as representing “the human past,” some of these groups harbor clues that enable us to formulate meaningful hypotheses regarding certain key aspects of that past.

    “The reason that “Western culture” with its individualist ethos is so attractive, and threatening, is that in many ways it is a purer reflection of the impulses which were operative in the ancestral environment.”

    This comes very close to my own view regarding the survival of ancestral values despite all the forces working against them through the millennia. For a summary of my research and a discussion of its implications, see the last chapter of my online book, “Sounding the Depths:Tradition and the Voices of History”:

  • Jason Malloy

    While this is certainly true, it is also somewhat misleading. According to my research, we can in fact isolate certain aspects of the culture of certain hunter-gatherer populations as representative of the culture of our Most Recent Common Ancestors in Africa

    This is the task of the paper linked above. The conclusion is worth quoting:

    The forager data allow us to explore relationships between habitat and social organization and compare humans to other species. Such relationships, in conjunction with the fossil and archeological record, can help model the behavior of our ancestors at different times in the past. The main obstacle is not contact with agriculturalists or climate change or bias toward marginal habitats, but technology; all foragers in the ethnographic record possess complex technology compared to all hominins before modern sapiens… As long as we take into account the effects of technology, the behavioral ecology of contemporary foragers can provide important insights into human evolution

  • Robert Dole

    The reason that “Western culture” with its individualist ethos is so attractive, and threatening, is that in many ways it is a purer reflection of the impulses which were operative in the ancestral environment. I am not here talking about the most extreme manifestations of Western liberality in sexual mores, such as gay marriage or formal polyamory (most people do not crave homosexual relations).

    Plenty of small human groups developed a 3rd gender role. The binary model looks to have become gospel truth only recently. Assumptions about the similitude of the sexual behavior of unitized pairs in a large, rule based society probably didn’t have room for the less common phenotypes on the continuous spectrum of fetal androgen exposure (despite the variability being almost certainly adaptive at the scale of a population).

  • Eric Michael Johnson

    Thanks so much for the additional insights on what I wrote Razib. As always you provide some excellent and much needed context to the genetic issues under discussion. I would like to add on to what Robert Dole brought up as I think it’s an important part of any conversation about the evolution of human sexuality. Certainly most people do not “crave homosexual relations” but it appears that many (perhaps even most) hunter-gatherer and forager societies include same-sex relationships and/or third gender identities within the sexual egalitarianism and flexibility that you discussed. These societies have been documented both today and in the late-19th century suggesting that it is not the result of cultural migration from Western civilizations. I wrote about this last year at Wired and will quote the relevant portion below:

    Native Americans use “two-spirit” to describe a person who simultaneously embodies a mixture of traditionally masculine and feminine identities, or two spirits residing in a single house. According to anthropologist Will Roscoe in his book Changing Ones, more than 155 North American societies have been documented as having two-spirit people (or “berdaches” as they were commonly called in anthropology). Some were men who took on traditional female gender roles, some were women who identified as men to become hunters, warriors or chiefs, and some were members of either sex who weren’t easily categorized. To the Crow they were bote, the Navajo knew them as nadleehi, while the Lakota called them winkte. Some had sexual relationships with women, some with men, some with both, and some eschewed sexuality altogether.

    “However, when the sexual preferences of berdaches have been reported a definite pattern emerges,” says Roscoe. “Male and female berdaches were sexually active with members of their own sex and this behavior was part of the cultural expectations for their role.” The gender roles that we’ve come to know as homosexual, lesbian, bisexual, and transgender were all represented in these societies, but in ways that were culturally specific and likely to have been quite unfamiliar based on our definitions.

    Chimpanzees have never been observed to engage in same-sex behavior but it is commonly observed in bonobos. This suggests that we can better understand the evolution of human sexuality by studying the function it serves in the latter (as well as the potential genetic correlates involved). Thanks again for your thoughtful discussion on these issues and I’m glad that what I wrote inspired you to reflect on them.

  • Grey

    “the “traditional” and normative social systems common among civilized societies since the rise of agriculture and the emergence of mass society are cultural adaptations which serve to constrain impulses which are deeply hard-wired within our species.”

    more recent for me but i think this is true, culture can act as a buffer against, suppressor of or accelerator of, natural selection


    There’s a lot of arguments over foragers and polyamory but it seems to me the most common form is nominally monogamous relationships with a lot of adultery on the side. The female side of this often seems to take the form of women trading sex for meat and in particular conducting affairs with good hunters when they think they may be pregnant as a primitive form of welfare. If multiple men think they may be the father then they may all bring food – as long as there’s not too many. If so then the traits controlling women’s sexual behaviour will have adapted to this environment.

    With a shift to agriculture and inheritance the males will want strict monogamy (on the female side) to ensure paternity – so a conflict arises between behaviour suited to the two environments of foraging vs farming.

    One path would be to leave it to natural selection, over time the more monogamous (or careful) women would have more children and the more promiscuous (or careless) would have less. Over time the frequencies for various sexual traits would shift. However in the transition that would be no use to families with forager-style daughters being thrown out by their farmer husbands.

    So culture steps in to coerce female sexuality to suit the new environment. There is still selective pressure but it’s diluted. “In the wild” the selection is: does an individual’s traits suit the new environment, yes or no? In the cultural version however there are three options instead: does the monogamous culture suit the individual’s traits, does it not suit them but they conform to it anyway (through simple coercion or through the action of other traits like religiosity), or thirdly does the monogamous culture not suit and they don’t conform?

    So culture can make the jump to a neccessary state faster than natural selection using coercion and then allow a weaker version of cultural selection to bring trait frequencies up to the coerced level.

    If so then the frequency of hypergamous and monogamous traits in women from different regions might be more or less proportional to the length of time those regions had a contiguous history of agriculture.

    I think there are other examples like male violence. Chagnon made a claim that Yanomani “killers” (unokai) had more children, a claim that is apparently very contentious e.g.

    but which i personally believe because descriptions of the Yanomani are more or less identical to how it is among inner-city street gangs where almost all the non drug-related violence revolves around access to females and being “fierce” gets more women – some females are attracted to it, some are too scared to say no, male rivals can be scared or stabbed etc.

    It is a high risk strategy but if anthropologists studied inner-city gangs i think they’d find the average number of children for the *successfully* fierce was higher.

    Culturally enforced monogamy is a good way to reduce the male inclination to violence.

  • Amy Cocks

    Problem there Grey, is the high failure rate of hunts, when even specifically evolved predators f*** up most the time.
    However, trapping makes a much better use of our capacity to learn, adapt and manufacture tools, only it requires more patience and intelligence than violence. It’s also open to both the sexes, and I’m pretty sure there’s nothing in a healthy pregnancy that’ll stop a woman being able to collect a kill from a net, basket or snare.

    Use of force to protect the traps and later, farmlands would make more sense (if you must insist that “male inclination to violence” is more than just a response to stress..)

  • ziel

    Plenty of small human groups developed a 3rd gender role.

    Is that really true?

  • Grey

    “Use of force to protect the traps and later, farmlands would make more sense (if you must insist that “male inclination to violence” is more than just a response to stress..)”

    Well in my case – speaking as someone naturally very aggressive – it’s a response to knowing that at an individual level i could use violence or the threat of violence to get what i want. I control it because i guess that control was bred into me by my ancestors not wanting to get hanged – while the guy not standing to my right isn’t standing there because his ancestors had the aggression without the self control – and the ancestors of the guy standing to my left didn’t have the aggression – but when the rule of law retreats from an area and a gang culture takes its place it gradually becomes just like Chagnon describes the Yanomani: reputation, being fierce, being an unokai, is one route to reproductive success – especially for the dumber ones.

    Seriously, anthropologists should study it. I worked in those kind of environments for a long time and only recently read up on Yanomani. It’s just the same.

    The terriotorial stuff is about controlling access to females too.

  • Allen

    Civilization is gay. Well, ultimately it isn’t even gay, it’s just asexual or haplodiploid at best. But on the way from converting a sexual species — a species made up of individual men and women — it has to mutilate their individuality to mold them into cells. It does this by promoting gayness, and any other perversion of genuine sex (the 600 million year-old kind of sex) that is expedient in service of “being part of something greater than ourselves.”

    All attempts by civilization to be humane during this transition, such as the secular “Rule of Thumb” or the religions that place the man in authority over their wives and children (actually this was secular as codified in Roman law to the point that he could kill legally kill them) are ultimately to no avail so long as “civilization” is the overriding value.

    At the boundaries between the civil and natural worlds are pseudo-men:

    police (and other “first responders”), soldiers, frontiersmen (cowboys), etc. On these pseudo-men is heaped all the mutilated masculinity of civilization — a granting of temporary, revokable, strings-attached reprieve in limited circumstances. Playing on that pseudo-masculinity was the genius of The Village People.

    Those not sanctioned to have even this mutilated masculinity, but who nevertheless exhibit it, are raped in prison.

  • Allen

    The reason that “Western culture” with its individualist ethos is so attractive, and threatening, is that in many ways it is a purer reflection of the impulses which were operative in the ancestral environment….Rather, a modicum of personal choice and sexual egalitarianism

    It may just more purely reflect one impulse, while denying another fundamental impulse. This may be why it’s viewed as threatening.

    In nature, males and females have two respective powers: To destroy and to preserve.

    People think that civilization is founded on control of destruction and seem to forget that civilization also depends on controlling female power to preserve. With the return to females of choice, hence their power, something equivalent must be done for males, such as enforcing natural duels to the death (natural meaning just putting the two disputants out in the wilderness with one to return). Of course, no one can face that this is the logical consequence of female liberation, so civilization slowly transforms into something unrecognizable except, perhaps, to the eusocial insects and their negation of sex.

  • Allen

    Two males of just about any species in nature will engage in natural duel. This common theme of natural duel is simply not compatible with maintaining a social organism like civilization in which the appeal of last resort in dispute processing is words.

    Once you remove this essential expression of masculinity, as civilizations always tend to do, you’ve removed the essence of masculinity. Most civilizations think they can get away with compensating for this by similarly “castrating” females through institutions like state or religion sponsored prostitution called “marriage”. That “works” for a while — maybe thousands of years, but eventually females will come to question this arrangement for very natural reasons.

    But by the time that has happened, everyone has forgotten that civilization also suppressed the natural duel. So things go really haywire and uncontrollably so as natural forces disrupt the culture starting in the limbic systems of virtually every citizen. You can only commodify this discontent and sell it back on DVD in the form of mano-a-mano fights at the climax of the movie so much. Something must give. That something is sex itself. And here we have, just in time, genetic engineering and cloning.

  • Jason Malloy

    “Certainly most people do not “crave homosexual relations” but it appears that many (perhaps even most) hunter-gatherer and forager societies include same-sex relationships and/or third gender identities within the sexual egalitarianism and flexibility that you discussed”

    Woooah…. I’ve only read your linked article, but you seem to make a lot of bad assertions. This claim is not consistent with the anthropology I’ve read, but just to make sure I consulted the Standard Cross-Cultural Sample*. I looked only at the 19 forager groups which engage in no farming, herding, etc. There are two questions about homosexuality, one asks about frequency (1 = absent/rare 2 = present/ not uncommon) and one asks about attitude (from 1 = accepted/ignored to 5 = strongly disapproved/punished).

    Kung – –
    Hadza – –
    Mbuti 1 5
    Adamanese 1 –
    Semang – –
    Vedda – –
    Tiwi – –
    Aranda – –
    C. Eskimo – –
    Montagnois – –
    Mic Mac – –
    Slave 1 –
    Pomo – –
    Paiute – –
    Siriono 1 1
    Botocudo – –
    Shavante 1 –
    Aweikoma 1 –
    Lengua – –

    There are only SCCS data for six forager groups, however I’ll also include the testimony from Frank Marlowe in his book on the Hadza: (“Two genders are recognized, and homosexuality, according to informants and my own observation, is absent, except in the sex play of youngsters”.) In all seven forager groups homosexuality is classified as ‘absent/rare’. However two groups also report attitudes (the Mbuti either disapprove or punish, and the Siriono either accept or ignore), so we might assume that it is simply absent in 5 of the groups, and rare in the other two.

    The complete absence of homosexuality among most forager cultures would be consistent with a study on the Aka of Central Africa published last year:

    Another reason we conducted a study of sexual behavior was that several years ago we asked Aka men about homosexuality and masturbation and were surprised that they were not aware of these practices, did not have terms for them and how difficult it was to explain both sexual practices. They laughed as we tried to explain and describe the sexual activities. We thought that maybe they were shy or embarrassed individuals, but this would have been uncharacteristic of the Aka we had known so long. All Aka and Ngandu indicated that homosexuality (gay or lesbian) was unknown or rare. The Aka, in particular, had a difficult time understanding the concept and mechanics of same sex relationships. No word existed and it was necessary to repeatedly describe the sexual act. Some mentioned that sometimes children of the same sex (two boys or two girls) imitate parental sex while playing in camp and we have observed these playful interactions.

    The authors also report that homosexuality is absent or rare in 59% of the world cultures in the SCCS dataset.

    * This is a popular topic for opinions, and the facts are ridiculously easy to check, so it’s somehow not surprising that I’m the first one to ever do it.

  • ohwilleke

    It is worth recalling that a lot of the change in the practice of elite polygamy happened during and after the Iron Age, rather than in deeper history, which suggests that food production shifts per se may not have been a dominant factor.

  • SeekTruthFromFacts

    Neither Mr Johnson’s article nor Hammer et al’s paper seem to deal with the possibility of serial monogamy due to deaths in childbirth. Wouldn’t that produce the same results in Hammer’s X-chromosome vs autosomal DNA comparison?

    Also, it seems odd that Basques are chosen along with the Han as the stars of polygyny. How could this be reconciled with cultural anthropological data?

  • Jason Malloy

    Here’s another informative variable from the SCCS. How “sexually egalitarian” are hunter-gatherers? (the most feminist, hetero-normative hatin’, proto-SWPLs since bonobos)

    The SCCS records attitudes about extramarital sex. The coding is

    1 = single standard prevails: extramarital sex allowed for both husband and wife
    2 = double standard: extramarital sex allowed for husband, but condemned for wife
    3 = double standard: extramarital sex is condemned for both sexes, but wife’s activities are punished more severely
    4 = single standard: extramarital sex condemned for both sexes and punished equally

    Kung 3
    Hadza 1
    Mbuti 2
    Adamanese 1
    Semang 4
    Vedda —
    Tiwi 2
    Aranda 2
    C. Eskimo —
    Montagnois 3
    Mic Mac —
    Slave 3
    Pomo —
    Paiute 4
    Siriono 3
    Botocudo —
    Shavante 2
    Aweikoma 1
    Lengua —

    Out of the 13 groups with data, 8 have a sexual double standard (62%), 3 allow extramarital sex for both men and women (23%), and 2 condemn it for both (15%). The modal forager culture allows extramarital sex for men, but condemns it for women.

    (For two of the cultures without attitudinal data– Mic Mac and Vedda– extramarital sex rarely to never occurs for both men and women, suggesting a de facto larger % for the marital sanctity cultures (27%).)

    Consistent with sociobiological expectations from paternal uncertainty, a sexual double standard for infidelity prevails among foragers.

  • Jason Malloy

    Sorry, “2 condemn it for both” equally, but 6 groups condemn it for both (46%), making the de facto % for marital sanctity cultures 53% (8 of 15), which also seems to be consistent with the general salience of monogamy in human evolution.

  • Grey

    Missed a point

    “Problem there Grey, is the high failure rate of hunts, when even specifically evolved predators f*** up most the time.”

    If hunters only succeed one day out of three then all the more reason for a female to have three hunters on the go – one openly, two on the side.

    “(if you must insist that “male inclination to violence” is more than just a response to stress..)”

    Thinking about it more i take back “male inclination to violence.” I think there are aggressive traits and restraining traits and the balance between the two can vary over time but what i’m getting at is that in the right circumstances being successfully fierce is a good reproductive strategy – not through being attractive (although it attracts some), not through force (although there’s a lot of that too), but through chasing off, wounding or occasionally killing rival males. This represents a lot of the norm among the inner-city underclass where the successfully fierce have 5-6 kids each with 5-6 different women.

    So not so much a male “inclination” as a viable male choice in some environments – especially if an individual happens to have fierce genes – and as it’s a successful strategy those fierce genes will increase their frequency among the population increasing the number of males for whom it is a viable choice. If those males with the potential to be successfully fierce can impose this regime through forcing other males to compete on the same terms then it is in their interest to do so.

    So what are the characteristics of the inner-city underclass environment that make it the right circumstances?

    – enclosed population who mostly stay on their own turf
    – terriotorial, the males of each terriotory attack any males from outside
    – basic subsistence doesn’t take too much time or effort
    – females can provision themselves with the basics
    – males can provide limited amounts of harder to get luxury items
    – no rule of law to turn being fierce into a bad strategy

    The females are limited to the males on their turf and one viable male strategy is to simply scare off rivals.

    In inner-city areas those conditions are met by a combination of welfare, drug-dealing and the surrender of the state monopoly of violence in those areas.

    However wouldn’t those conditions also be met in any semi-abundant forager environment where there was no state authority to begin with?

  • Justin Giancola

    Allen “the genius of The
    Village People.”

    Body, body, body wanna feel my body,
    Body, body, body gonna thrill my body,
    Body, body, body don’tcha stop my body,
    Body, body, body it’s so hot my body!

  • Jason Malloy


    I just discovered that Marlowe has a slightly more in depth paper challenging the marginal habitat theory. He expands on the qualifications that you highlight from the paper I linked earlier by arguing that an ideal measure of secondary biomass would more than likely show even better habitats for foragers. One novelty of this analysis is that it also includes the habitats of other marginal groups who should have been displaced given the same assumptions:

    The same logic that suggests foragers should occupy more marginal habitats than agriculturalists also suggests horticulturalists and pastoralists should occupy more marginal habitats than intensive agriculturalists. It is intensive agriculturalists who have the largest populations and became the most politically dominant once state-level organization was achieved. As our results show, however, horticulturalists occupy more productive habitats, and pastoralists occupy less productive habitats than intensive agriculturalists. Different sorts of subsistence occur in different types of habitats.

  • Jason Malloy

    Because of this post I went and picked up Sex at Dawn at the library a few days ago. I’m about 40% through, and its typical nonsense from sub-academic huckster Chris Ryan (he cussed me out and banned me from his blog several years for having the audacity to link to research that contradicted his frequent forays into the fallacious). In fairness, it’s not badly written and when he’s not fantasizing about foragers as pan-sexual communists or “debunking” sociobiology, he’s occasionally on the right side of important arguments (for example).

    Also, I found yet another genetic study from 2011; it utilizes mtDNA from hunter-gatherers to construct cultural phylogenies, and again finds evidence for low reproductive skew:

    The reconstruction of human marriage practices for ancestral humans show several consistent patterns using Bayesian, maximum likelihood, and parsimony methods (Table 1). The reconstruction of low levels of polygyny in early humans is straightforward because high levels of polygyny for hunter-gatherers are only found in Australian Aborigines and are mostly low elsewhere (most exceptions are some New World foragers that are not in the phylogenetic analysis). Low levels of polygyny and low reproductive skew among ancestral humans are consistent with human morphology and behavior (i.e., moderate sperm counts and testicular size; facultative paternal investment) and the general decline in sexual dimorphism beginning at least with early Homo.

  • Grey

    “he’s occasionally on the right side of important arguments”

    The political arguments masquerading as science break down to
    – humans are innately x (where x suits one political agenda)
    – humans are innately y (where y suits a different political agenda)
    – humans aren’t innately anything (and therefore can be moulded to suit a political agenda)

    The right side of the argument surely is that human populations can be defined in terms of trait frequencies and in a suitable physical or cultural environment any trait can increase in frequency over time and in unsuitable environments it can decrease. This means human characteristics are both fixed and mutable, innate and environmental – but at the genetic level of environment i.e. generational.

    – population groups are innately x (when x has been selected for over generations)
    – population groups are innately y (when y has been selected for over generations)
    – the innate aspects of population groups are mutable but over generations

    So if certain conditions are met for enough generations
    – humans are innately x
    and under different conditions
    – humans are innately y
    but they’re always innately something.

    One of the things about fierceness polygyny (to coin a phrase) is it’s not in the interests of the majority of males (and as it’s selecting for a propensity for sudden flashes of extreme violence it’s not that great for the females either). So it would be in the interests of the other males to institute some form of “rule of law” if they can where you could even define “rule of law” as rules designed to stop fierceness being a good reproductive strategy. This might imply that fierceness polygyny has a strong tendency to morph into something else if/when people figure out how e.g. arranging marriages between lineages.

    “and the general decline in sexual dimorphism beginning at least with early Homo”

    Fierceness polygyny doesn’t rquire a great deal of sexual dimorphism because most of the violence isn’t fair. It’s not like gorillas duking it out where you have to be one of the 3-4 biggest gorillas to have a chance. Humans cheat. If the number 2 guy is a lot smaller than the number 1 guy then he’ll jump him when he’s not looking and stab him in the neck. Chagnon mentions a yanomani unokai who’d killed sixteen men, guessing from the the inner-city version i doubt he’s particularly big, more likely thin and wiry with very low empathic restraint – the other guy hesitates a fraction of a second more than the unokai. I’d say sexual dimorphism for propensity to violence in humans is much more mental than physical – a fierce little guy is much scarier than a peaceable big guy.

    Interestingly enough i’d say (physical) sexual dimorphism in humans is more likely where violence is restrained. If females can mostly provision themselves limiting that form of male competition and males are also restricted from using violence and intimidation by a rule of law then the women might select for physical size, loudness, showing off – entertainment value basically.

  • rich lawler

    A peripheral point to this interesting discussion…

    Eric wrote,

    “Chimpanzees have never been observed to engage in same-sex behavior but it is commonly observed in bonobos. This suggests that we can better understand the evolution of human sexuality by studying the function it serves in the latter (as well as the potential genetic correlates involved).”

    Eric, I’m pretty sure you took Christine Drea’s “Primate Sexuality” course at Duke. In her lecture on Sociosexual Behavior she has a few examples and photos of common chimpanzees engaging same-sex behavior (in the section on reconciliation). In any case, I presume when you are talking about chimps not engaging in same-sex behavior, you mean not engaging in erotic sexual behavior. However, there are many examples of chimps engaging in same-sex sociosexual behavior, which is non-erotic and occurs more in a social context (reconciliation, appeasement, reinforcement of dominance, etc.)…This is the reason why Lord Solly Zuckerman–a very interesting fellow himself–came up with the distinction (sexual versus sociosexual behavior) in the first place. I would suggest that it’s difficult to separate same-sex sociosexual behaviors from same-sex erotic behaviors in bonobos (and most other primates species). In this regard, nonhuman primates offer limited insight into the erotic homosexual behaviors we see in humans, since almost all instances of same-sex behaviors in nonhuman primates appear to be un-erotic and embedded in a social context, not a sensual, orgasmic, and amatory one. This distinction–same-sex erotic versus same-sex sociosexual–probably also applies to some of the examples of homosexual behavior in human cultures as well. Don’t get me wrong, we have much to learn from studying the sexual behavior of nonhuman primates but when making comparisons to human sexual behaviors we need to make sure our comparisons are homologous.

  • Grey

    MAOA was mentioned on here recently so some thoughts on this discussion about yanomani and unokai and possible connections to MAOA based on experience in urban underclass environments.

    There’s some very specific behaviors related to the “unokai” type which doesn’t fit the phrase “warrior gene” as a cultural icon (but maybe does fit historical reality). So if researchers are looking for “warrior” traits in some heroic or bravery sense they won’t find it.

    Also, although,

    actual aggression ~ innate aggression minus restraint

    if MAOA maps to the thing i think it does then it doesn’t map to greater natural aggression per se. It increases actual aggression by reducing restraint. An unokai may have varying levels of aggression as well but the main difference is in the lack of restraint.

    Also i used to think the lack of restraint was just impulsiveness as that’s very common in the same areas but again an unokai type may have varying levels of impulsiveness as well but with unokai it’s a specific kind of impulsiveness (in my opinion).

    1. The standard unokai kill.
    Gang leader arguing with some guy over something. Other gang members form a little semi-circular huddle behind the leader. The unokai is at the back with his hoodie up, hand on his knife – they almost always carry a weapon because they assume everyone is like them – and he slowly shifts round the side of the group until he is behind the guy. He stabs him 3-4 times in the side. The rest of the gang if they have knives may stab him 1-2 times each after he goes down to make sure they get their name on the kill but not till after the unokai has made him defenceless.

    2. Unokai are ambush or surprise killers. They’ll back away from a fair fight and their only consistent form of restraint is not having a weapon. If they get in an altercation and don’t have a weapon or some other major advantage over the other guy they’ll back off and get a weapon and come back.

    3. Online gamers
    Some online games with player vs player combat and killing exemplify this behavior. With most online shooters the players are all the same and have an equal chance. With others it’s possible for players to give themselves extreme advantages over other players which they exploit mercilessly. It’s all about not giving the other guy a chance. A lot of the people who play the latter kind are likely to have it.

    4. Good MAOA experiment
    I was reading about some MAOA experiments. If it’s what i think it is a good experiment would be:

    Get a beef carcass and hang it from the ceiling add table and a nasty looking knife. Bring subjects in one by one and ask them to stab the carcass. Optional, hang a picture of a nice cow on the wall behind. The picture may not be neccessary but the aim is to calibrate it to the point where the most empathic of the female subjects has a hard time even picking up the knife. If it’s calibrated to that point then most of the other subjects won’t be able to stick it right in. Some particularly strong guys might by accident. The unokai will stick it in to the hilt even to the extent of taking a little run up or twisting to get some torque on the strike.

    (There’ll be a separate group with the MAOA (if it is the cause of what i’m thinking of) who won’t do it (because they have other over-riding empathic restraining traits imo). Offer $100 to a children’s charity if they stick it right in and they’ll do what the unokai did i.e. the little run-up or twist to get extra force.)

    5. Empathic restraint
    The other critical difference you’d see with unokai in the above experiment (or similar) is they’ll smile or laugh afterwards. This is the big thing. They always do that. Hurting gives them a rush – even if it’s a dead cow. Most normal people hesitate before hurting someone which i think is partly empathic restraint. Not having that empathic restraint can look like a higher level of aggression or higher level of impulsiveness but it’s actually a lower than “normal” level of hesitation. Given the smiling and laughing thing i’d go further and say it’s almost an anti-empathy where they get a rush from it.

    6. I think the frequency of this trait has been increasing for decades in underclass, gang-dominated environments because it has reproductive advantages. If you tested men in their 60s and 20s from a place like that i think the men in their 20s would have a higher frequency or if you had blood tests of men from those environments in their 20s from the 1960s and compared them to now.

    7. If MAOA = the unokai thing = the specific thing you see in gang-dominated underclass populations then it’s responsible for tens of thousands of killings over the last 50 years. There’s a lot of aggression and a lot of impulsivity and subsequently a lot of general violence in underclass areas but the level of lethality of that violence is very disproportionately skewed to this very specific type of individual.

    8. In populations subject to a rule of law the trait will both decrease in frequency and be suppressed. If you were trying to predict MAOA type behavior among a population like that then you’d need to imagine the least detectable form of ambush-killing or fierceness polygyny in that kind of environment. I’d suggest incapacity-rape where a man of this type goes to a social gathering place of some kind looking for women who are drunk / drugged and incapable.


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About Razib Khan

I have degrees in biology and biochemistry, a passion for genetics, history, and philosophy, and shrimp is my favorite food. In relation to nationality I'm a American Northwesterner, in politics I'm a reactionary, and as for religion I have none (I'm an atheist). If you want to know more, see the links at


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