Sexually despotic men rewrite history

Alfred L. Kroeber (left) with Ishi, the last member of California’s Yahi people, in 1911. Wikimedia Commons
Alfred L. Kroeber (left) with Ishi, the last member of California’s Yahi people, in 1911. Wikimedia Commons

“Heredity”, opined the pioneering cultural anthropologist Alfred L. Kroeber in 1915, “cannot be allowed to have acted any part in history”. I have yet to encounter a crisper expression of the view that biological explanations have no place in the study of society and history. Kroeber’s words have resonated through the social sciences for a century, divorcing nurture from nature, social from biological, at considerable harm to our understanding of society and what it means to be human.

 

Fortunately, many 21st Century anthropologists, economists, neuroscientists, geneticists, sociologists and thinkers so busily inter-disciplinary that they defy dusty departmental labels, are consigning the hoary distinction between nature and nurture to the past. Likewise the distinction between heredity and history is steadily dissolving as the where intimate links between evolutionary fitness and major historic transitions come into view.

Last week’s European Journal of Human Genetics, for example, carried a fascinating article led by evolutionary geneticist Patricia Balaresque exploring the signature of historic population expansions in the distribution of Y-chromosome genotypes of men alive today.

The Y of who, what and when

The the human Y chromosome represents a tiny portion of the genome, including the genes that trigger a foetus to develop into a male, rather than following the default female pathway. Every now and then a small change occurs in one of the less important parts of a Y-chromosome’s DNA. Such a change is passed to a man’s sons, those sons’ sons, and so on. That means there’s quite a bit of variation in these Y-chromosome sequences in any human population.

Marco Polo at the Kublai Khan. Miniature from the Travels of Marco Polo c 1298.
Marco Polo at the Kublai Khan. Miniature from the Travels of Marco Polo c 1298.

So if a man happens to have many sons, who each go on to have many sons and so on, one might detect a sudden surge in the frequency of the Y-chromosome sequence borne by that line of men (patriline). In 2003, a large team from Oxford University detected evidence of just such an event. Across much of Asia, one particular Y-chromosome sequence was carried by 8 percent of all men. In a paper pithily titled “The Genetic Legacy of the Mongols”, they famously fingered Genghis Khan as the chief suspect.

The pattern of variation within the lineage suggested that it originated in Mongolia approximately 1,000 years ago. Such a rapid spread cannot have occurred by chance; it must have been a result of selection. The lineage is carried by likely male-line descendants of Genghis Khan, and we therefore propose that it has spread by a novel form of social selection resulting from their behavior.

Where by ‘behaviour’ they mean more than the Great Khan’s triumph in unifying the Mongols and establishing the largest continuous empire history has ever known. For Khan was as much about the establishment of a genetic dynasty as a political one. According to one disputed quote, he once said:

The greatest joy for a man is to defeat his enemies, to drive them before him, to take from them all they possess, to see those they love in tears, to ride their horses, and to hold their wives and daughters in his arms.

Or words to that effect.

Such a genetic legacy is far more than the work of a single man. It is likely that Khan’s uncles, brothers and cousins, played a substantial role, too. And his direct male descendants spread both his empire and his genetic legacy. Ghenghis’ grandson, Kublai Khan, married four main Empresses, but, according to Marco Polo’s Travels was attended to by hundreds of beautiful young women, working five at a time in three-day shifts. And a much greater number of women, recruited to the palace but, after a second round of screening, not deemed perfect enough for the Khan himself, were bestowed on Kublai’s nobles, many of whom would have been relatives sharing his patriline and Y-chromosome.

Khan not the only one

The Mongol expansion is far from the only such event to leave a genetic signature. A 2005 paper identified a particularly successful lineage that expanded about 500 years ago in Northeastern China, possibly through the lineage who established the Quing Dynasty.

Last week’s findings report on a survey of 5321 men from 127 Asian populations, testing for evidence of similar population expansions. Belaresque and her collaborators identified eleven such events, including the ones tied to the expansions of the Mongols and the Qing dynasty. And some of those events date back as far as 2100 BCE.

The earliest expansions, between 2100 and 300 BCE, are associated with the flourishing of agriculture in the Fertile Crescent, East India, and South East Asia. As agriculture took hold, elites accumulated wealth and influence beyond anything our hunter-gatherer ancestors could have conceived. These represent perfect conditions for sexual despots: male rulers who take many wives, keep numerous concubines or mistresses, and have many offspring. They also establish successions that favour their male descendants, handing them the wealth and power to become sexual despots themselves.

Another expansion began around 1100 CE in the Near East and expanded to the South East Indian coast. This might be a signature of the “rapid expansion of Muslim power … after the establishment of a unified polity in the Arabian peninsula by Muhammad in the 7th Century and under the subsequent Caliphates”.

The Mongol and Qing expansions, and another from Northeast China beginning no earlier than 850 CE, were not associated with the establishment and spread of agriculture, but rather with nomadic, pastoral lifestyles made possible by the domestication of horses. Pastoral nomads ruled the steppes for thousands of years, thanks to their horse-powered mobility and fighting ability.

They established several empires, giving rise to hierarchies, elites and patrilineal reproductive despots like the Khans and the Qing. And their Silk Road trade corridor facilitated westward expansion of their genetic dynasties.

Heredity and History

Even in the rather well-studied case of Genghis Khan we are well beyond certain idenfification of the individual progenitors whose success sparked each expansion. Innovative analyses and lucky ancient DNA finds may yet do so for some cases. But the ability to detect great tides of patrilineal descent in societies of various types offers far more interesting possibilities than compelling personal narrative.

The evidence shows that with great power and wealth can come great evolutionary fitness. The tools are now falling into place to assess how much the psychological adaptations that shape reproductive success have given history its shape.

This is one tale where History certainly represents HIS Story. The fact that new Y chromosome sequences can spread so fast and so wide when history’s tide turns suggests that a very small number of sexually despotic men can leave massive numbers of descendants. But each man who traces his descent back to Genghis Khan or another such super-ancestor through an unbroken male line has sisters who do so too, save for the very last branch in their family tree. If 2% of people in Asia descend on a male-only lineage from the same male ancestor as Khan, then how many times do they descend from him through at least one female ancesor?

Each of us descends many times over from a great many sexual despots. It would be Kroeber-like wilful ignorance to be think we don’t also inherit many of the genes that biased their behaviour toward the accumulation of power, the vanquishing of rivals and reproductive despotism.

And when I say “we”, I don’t only mean men. Every man has a mother. Every descendant of Ghenghis Khan is also a descendant of his mother Hoelun.

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Fear not the hipster beard: it too shall pass

If you haven’t been outdoors in a few years, you might not have noticed that beards are back. Back in such a big way that apparently many New York hipsters are paying north of US$8,000 for “facial hair transplants” to embellish their patchy beards.

While the hipster subculture appears to be ground zero for the latest swerve toward beardedness, men who would not be seen dead in skinny jeans or thrift-shop cardigans are letting the whiskers grow in a way that hasn’t been fashionable for decades.

Why are beards sprouting from the unlikeliest faces? And is there anything that might make them stop?

The advantage of rarity

Today in Biology Letters we provide experimental insights into why beard fashions come and go, and why there is no single optimum pattern of facial hair. By we, I mean my former Honours student Zinnia Janif, my colleague and Zinnia’s co-supervisor Dr Barnaby Dixson and me.

We speculated that a phenomenon called “negative frequency dependence” (NFD) might help explain diversity in facial hair patterns. Negative frequency dependence simply means that rare traits enjoy an advantage.

In evolutionary genetics, NFD selection is an important force, favouring rare genetic alleles over more common ones. In guppies, for example, males bearing rare combinations of coloured spots are both less likely to be preyed on and more likely to gain matings in the wild. So a rare colour pattern can spread very rapidly until it becomes so common it attracts attention from predatory fish and starts looking like old hat to female guppies.

A sample of male guppies, caught from Alligator Creek, North Queensland, where they occur ferally. The size and placement of colour spots in male guppies is among the most genetically variable traits yet studied.
Rob Brooks

The selective advantages enjoyed by rare colour patterns explain why guppy colour patterns are among the most genetically variable traits yet studied. Could more subtle forms of NFD selection explain why so much genetic variation persists in most traits, even though natural selection is expected to remove genetic variation by eliminating “bad” genes. Under NFD, “good” or “bad” depends on how common the gene is.

What if, we speculated, rarity also operated in the world of fashion? In this case, what if rare patterns of facial hair enjoy an advantage purely on account of their rarity?

Experiment

To test this idea we set up a simple experiment using a suite of photographs of 36 men. Each man had been photographed when clean-shaven, with five days of growth (we call this light stubble), 10 days of growth (heavy stubble) and at least four weeks of untrimmed growth (full beard).

One subject displaying the four levels of beard: clean shaven, five-day growth, 10-day growth and full beard.
Barnaby Dixson

Subjects, recruited via our research group webpage (where we are always seeking subjects and Facebook – thanks IFLS for the traffic), each rated 36 faces – one of each man. Over the first 24 faces we manipulated the rarity of beard types. Subjects either saw all 24 men clean shaven, all 24 with full beards, or six men from each of the four levels of beardedness.

We then analysed how subjects rated the same – last – 12 pictures comprising three from each beard level. In line with our prediction, when clean-shaven faces were rare (among the early 24 pictures) they enjoyed a significant premium in attractiveness ratings (in the last 12) over when they were common. And when full beards were rare or when the four levels of beardedness were evenly distributed, full beards enjoyed significantly higher attractiveness than when full beards were common. Five- and 10-day stubble did not really vary in attractiveness across the three treatments.

What this means is that, under experimental conditions at least, patterns of facial hair enjoy greater attractiveness when rare than when they are common. Whether this scales to more nuanced judgements in the more complex and varied real world remains to be seen. But it suggests that beard styles are likely to grow less attractive as they become more popular. And that innovative new styles may enjoy a premium while they are still rare.

Fashion and facial hair

Negative frequency dependent choices might well be an important ingredient in changing facial hair fashions. The current fad for facial hair is just the latest development in a long history.

Dwight E. Robinson went to the trouble of scoring the facial grooming of all men pictured in the London Illustrated News between 1842 and 1972. In the 1890s, more than 90% of men pictured had some form of facial hair, a figure that dropped to below 20% by 1970. Sideburns occupied the news in the mid-19th century, whereas full beards reigned from 1870 to 1900, only to be replaced by moustaches.

Negative frequency dependence might play a role early in an establishing fashion.

The New York Times reckons the current beard trend emerged among local hipsters in late 2005. I’m not sure the NYT would notice anything that happened or – heaven forbid – started outside of Manhattan or Brooklyn. But suffice to say the current fashion has been almost a decade in the making.

Noveau-beard has been propelled along the way by various sportsmen, movie stars and musicians. But the fashion has now spread to the point where astute commentators reckon the tide of hipster cool has turned. When Buzzfeed breathlessly lists the “51 Hottest Hollywood Beards”, it’s time to seek higher ground to avoid the tsunami set off by the implosion of cool.

That is one way in which negative frequency dependence can work: when a fashion goes mainstream it loses the advantage of rarity. And so it begins to subside.

“Joaquin Phoenix is a Poser”. Graffiti stencil, New York City.
David Shankbone/ Flickr

Not everybody should grow a beard

Much of this discussion has concerned the attractiveness of beards. But although many hirsute men have formed the zealous conviction that their beards place them at an advantage with the ladies, evidence is far more equivocal.

Dixson’s previous research has shown that heavy stubble – a substantial growth that is well kept – is more attractive than clean shaven, light stubble or a full beard. And individual women vary in their tastes, some are pro, and others vehemently anti-whisker.

Far less ambiguously, beards tend to make those men who can grow them look more masculine. Hardly surprising, actually, given the ability to grow facial hair kicks in during puberty, marking the transition to manhood. The beard might be as much a signal to other men as it is to women, which might explain why so many warrior cultures grew resplendent beards, and why professional sports teams grow beards in playoff-time solidarity.

Female attraction to bearded men can arise due to the manly connotations of facial hair. Nicki Daniels certainly makes this point in her hilarious Open letter to bearded hipsters.

Unfortunately, you guys have turned it into a fashion statement. The beard has turned into the padded bra of masculinity. Sure it looks sexy, but whatcha got under there? There’s a whole generation running around looking like lumberjacks, and most of you can’t change a fucking tire.

If the messages signalled by growing facial hair are diminished when every man-boy over 20 is sporting a beard, that constitutes another way in which negative frequency dependent choice might work.

The reasons beards diminish in value when everyone is wearing them remain to be teased apart, but the fact that they do suggests that the hipster beard, like the handlebar moustache, the mutton chop and countless other fashions before them, will, in time, pass.


“Jimmy Niggles”, grew Australia’s highest-profile contemporary beard to raise awareness about melanoma. Now he’s looking to sell it for A$1million to support cancer research.
Tim Jones

P.S. Beard Season is coming up

You may already have encountered Jimmy Niggles (aka Scott Maggs) and friends who are raising awareness about melanoma – in honour of their mate Wes who lost his life to melanoma at age 26 – through their Beard Season campaign. Jimmy uses his resplendent beard to start conversations with strangers (and leverage considerable media interest) about the importance of having their skin checked. Jimmy is currently selling his beard for A$1 million in order to raise money for melanoma research.

Talk about a positive expression of contemporary masculinity.


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Rob Brooks does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.

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