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Returning to a favorite theme here — debunking the balderdash that recent human evolution is cultural rather than biological — consider how simple technological changes can influence human biological evolution. Take musical instruments: in an environment with no musical instruments, and thus essentially no music, you’d never know who were the rockstars (if male) or the dancing queens (if female). With no way to detect these sexy phenotypes, natural selection could not change the frequencies of alleles that contributed to them. But once the presence of musical instruments becomes a predictable feature of the environment, suddenly there’s a pressure to be a good performer, and so traits both physical (dexterity, agility) and psychological (extraversion, emotional volatility) will increase, at least up to a point where any further increase would be a bad bet for newcomers as they crowd an already saturated niche. It’s hard to show off when everyone else shows off in the same way.
Now, we commonly urge youngsters to “find their niche,” yet many people ignore the obvious corollary of this ecological phrase, namely that whatever cultural processes spawn new niches will also result in a change in frequency of alleles implicated in the traits needed to thrive therein. Unlike Darwin’s finches, humans don’t need to expand into an unsettled archipelago to undergo adaptive radiation — we can stay fixed geographically but broaden the range of niches in our “social-cultural space.”
At my personal blog, I sketched out a reason for why technological progress tends to be more bustling than progress in more abstract disciplines like geometry, where progress appears to stagnate for quite awhile until “the next big thing” comes along. Basically, the purer arts and sciences are the hobbies of weirdos, whereas technology is usually a matter of life and death: i.e., outperforming the technology of your adversaries. This literal arms race keeps the pace of technological progress much more frenzied than in other cultural areas. The key is that new shields, spears, guns, and ships don’t affect the fitness of just soldiers, because most of this new stuff will be ripped off by others to innovate civilian life.
For instance, there would be no common cars if militaries had not pioneered the technology of interchangeable parts and mass assembly-line production for ships and firearms. Nor could their interiors and exteriors be held together were it not for the common use of steel, an alloy whose first modern production method — the Bessemer Process — resulted from its inventor’s efforts to more efficiently produce firearms for the Crimean War, and whose Captain of Industry (Andrew Carnegie) made his fortune through contracts to build warships for the US Navy. And since the widespread availability of the automobile, many males have carved out a niche whose appeal to females centers around owning a car when other males don’t (the guy in 10th grade with his own car) or using their car to signal machismo (drag racers). So, to paraphrase a related slogan on technological changes fueling biological changes: howitzers hatched heart-throbs in hot rods.
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Drag racers are not sexy.
The Maserati Quattroporto is sexy.
This does nothing to explain the low birth rate in Italy.
how does this theory explain the prevalence of geeky activity such as electronic gaming? the need for quick calculation led to computers which led to gamers, but geekiness is more often than not considered a negative signal for females. how does geekiness perpetuate itself or has there not been enough time to predict how this will sort itself out?
Did you say no music before musical instruments? How about song? Also, simple percussion — beating sticks together, or better yet, hand clapping and foot stomping — was probably there long before, say, simple flutes. Dancing, ditto.
I agree with your ultimate point, but I do not think Andrew Carnegie’s steel interests or US Steel (its succesor) ever built warships. They did make armor plate for warships. Bethlehem Steel was in the warsip business
There’s a question about sexual selection I’ve always wondered: how does the preference for a certain trait arise in the first place? The peacock’s tail is supposed to be handicapping (though it still seems odd to me). Why are extroversion and emotional volatility desirable? And couldn’t they express themselves easily in other ways in without music?
I think there’s a lot to it. New niches crop up, and — to everyone’s surprise — previously unnoticed creatures take them over. Geeks are a good example. Anyone old enough can remember when “the geek” wasn’t a big or much-visible part of society. Computers caught on, and suddenly geeks are everywhere, and geek taste (sci-fi, Wired) becomes important. Another example: When a quirky beauty becomes famous, suddenly you find yourself surrounded by girls who look like her. The world is suddenly full of Meg Ryans, or Britneys, or Lindsays. Were they always there, and we didn’t notice them because we had no template to stick ’em in before the star established the the template? Did the star’s success make it possible for the girls to assert their quirky looks with some confidence? I remember noticing this with Claire Danes, for instance. She became an It Girl, and suddenly the world was full of Clarie Daneses. Where had they been?
Music w/o instruments = a capella. Hitting sticks against logs isn’t really percussion; to get a good sound and rhythm you need an instrument. It’s not that it didn’t exist, but was barely there. It’s difficult to get down to a capella. I imagine that selection pressures to have a good singing voice increased after instruments were invented — since they’re standardized and tune-able, the discrepancy between your fallible human voice and the technology’s tone is hard to ignore. That would separate virtuosos from amateurs: “Wow, her voice sounds just like a flute!”
Extraversion & emotional volatility aren’t sexy per se, but they’re necessary for an exhibitionistic personality. The increase of intraversion is the big puzzle, since we started out pretty social. You need a pretty complex society like ours, one in which you can contribute to it even while living almost like a hermit. So obviously agriculture played a huge role in allowing introverts to increase in frequency.
Now, geeks — it’s too early to tell, but there certainly are more of them here than in an H-G tribe. The pressures on IQ and personality are just different, and have been for awhile.
As for qualities as specific as “Claire Danes-ian quirkiness,” their desirability comes and goes too quickly for it to have long-term consequences. That’s why over the long-term a lot of genetic variation has been preserved in personality traits — it’s up to capricious fashion whether or not your personality will mark you as an It Girl, and thus whether or not you’ll be the object of the alpha-males’ desire. You could get “bet-hedging” at a genetic level because of this.
The stuff about fashion, though, is a separate topic from technological change inducing frequency-dependent selection, and I’d have to look into how widespread the “ever-changing criteria for being an It Girl” aspect was throughout history. That may be a pretty recent invention of the mass media.
geekiness is more often than not considered a negative signal for females.
I don’t think that’s true, wongba. I think “geekiness” can serve as a proxy for qualities such as prowess with technology or facility at abstract thought, which in the Western world today often correlates with material success & therefore ability to provide for a family. Granted, women may not fawn publicly over geeks the way they do George Clooney or whoever. But that doesn’t mean they don’t want a geek of their own to come home to.
There may also be a connection with this, from the 3/26 World Science piece on human evolution http://www.world-science.net/exclusives/070326_evolution.htm:
In the June 2003 issue of the research journal Current Anthropology, Helen Leach of the University of Otago, New Zealand wrote that skeletons from some populations in the human lineage have undergone a progressive shrinkage and weakening, and reduction in tooth size, similar to changes seen in domesticated animals. Humans seem to have domesticated themselves, she argued, causing physical as well as mental changes.
It’s not clear what “populations” Leach refers to, but in a world where physical strength isn’t as important to physical survival, maybe geekiness aka facility for abstract thought carries more weight than it once did, as people select potential mates. In which case we’re possibly creating a race of geeks. Kewl.
Two books that may be of interest:
The origin and evolution of cultures (by Robert Boyd and Peter J. Richerson)
Not by genes alone : how culture transformed human evolution (by Peter J. Richerson and Robert Boyd)
Agnostic: “The stuff about fashion, though, is a separate topic from technological change inducing frequency-dependent selection, and I’d have to look into how widespread the “ever-changing criteria for being an It Girl” aspect was throughout history. That may be a pretty recent invention of the mass media.”
I wonder … Cameras have been around since the mid-1800s, movies since around 1900 … And, as everyone knows, there are certain faces and body types (and certain behaviors) that seem to register well in photos and movies. If the tech and media environment encourages this set of attributes, if certain types and feature-and-temperament-collections seem particularly desirable thanks to cameras and movies, then it might happen that these alleles get a boost, no?
The claim I’ve read (I think in _Before the Dawn_) was that various tongue-click soundes occur almost exclusively in some of the oldest African languages, apparently near the root of all human languages.
This offers an interesting opportunity for looking at gene/language interactions, right? It would be interesting to see if there’s some inherent difference in ability, ultimately genetic, which makes those sounds easier to make/hear/differentiate. This might explain why they disappeared from languages. While they’re part of the local languages, the ability to use them is selected for; when they fall out of use for many, many generations, there’s nothing preventing that ability from falling victim to drift.