The latest evolutionary psychology[1] theory to do the rounds is that blondeness evolved as a selection strategem for women trying to attract scarce mates in the harsh and male-scarce conditions of Ice Age Europe. According to this report in the Times, the theory has been formulated by an anthropologist, Peter Frost. His supporting argument is that blondeness is a signal of high levels of oestrogen. I suppose I should wait for the article which is supposed to come out in Evolution and Human Behaviour, but I can’t resist pointing to an obvious hole and an alternative explanation.
The obvious hole is that blond(e)ness is not a sex-linked characteristic. If light hair colour signals high oestrogen, blond men should have a lot of trouble attracting mates. Tempted as I am by this hypothesis (see photo here), I can’t say I’ve seen any evidence to back it up.
The alternative explanation (not at all novel) is that fair hair arose in conjunction with pale skin, as a straightforward physical adaption to the move away from the tropics – less need for pigment, or maybe more need to absorb vitamin D.
The Times article also gets bonus points for repeating the claim (which I’ve seen doing the rounds for decades) that blondes will become extinct some time soon because the relevant genes are recessive. Those making this claim should go back to their high school text books and look at Mendel’s peas. Remember how the recessive phenotypes turned up again in the second generation?
After writing this, I found a piece by Frost here. He has a response (unconvincing in my view) to the physical adaption theory, and doesn’t raise the oestrogen idea at all. In this piece he argues, a bit more plausibly, that the harsh environment selected for colour polymorphism, rather than any particular colour scheme.
fn1. I know I’m always bashing this stuff, but only because so much of it is silly projections of contemporary culture-specific values onto a largely hypothetical evolutionary environment. Some aspects of EP, like Pinker’s theory that we have evolved highly advanced mechanisms for lying and lie-detection, seem quite plausible to me.
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derrida derider 03.05.06 at 6:12 pm
Yeah, the main difficulty with EP is avoiding ‘just so’ stories (possible but untestable hypotheses).
The number of these that many popularisers and some practitioners put forward unfortunately gives a lot of ammo to those ideologues who want to discourage people from even thinking about EP.
Todd 03.05.06 at 6:54 pm
John Hawks has a good post on blonde extinction from last weekend.
The Commissar 03.05.06 at 7:30 pm
I haven’t read Hawks’ post yet … but here goes …
Recessivity has nothing to do with it. If the blonde genes are relatively scarce in the total population, genetic drift probably will eliminate them.
Now I gotta see what Hawks’ says.
The Commissar 03.05.06 at 7:32 pm
Hmmm. Wrong again.
Brandon Berg 03.05.06 at 7:41 pm
But the recessive phenotypes are rarer in the third generation than in the first (25% versus 50%). If the blonde alleles are concentrated in a small sub-population (say, 5% of the world’s population is blonde and another 10% are carriers), then blondes will be much more common than they would if interbreeding caused the blonde alleles to be distributed randomly among the world’s population (in which case you’d have 1% blondes and 18% carriers).
Of course, this assumes a two-allele model of hair color, and probably a greater degree of interbreeding than is realistic, but I’m pretty sure the general principle holds.
serial catowner 03.05.06 at 7:42 pm
What is needed to understand these events is the “salmon lure” analogy.
Although the lure resembles the flash of a herring, that is not why the salmon strikes at it. Spawning salmon don’t eat much. Some say the salmon strikes at the lure because it makes them angry.
Whatever. The point being, when men look at blondes, they do not see a demographic, or a swelling population statistic. They are entranced by a woman who would look good advertising toothpaste, or possibly stepping out of an expensive car.
Like the salmon, whatever they thought they saw…they didn’t. Yet, life goes on. The eternal mystery.
Todd 03.05.06 at 8:03 pm
Ah, the interwebs: home to such amazing creatures!
y81 03.05.06 at 8:12 pm
Well, amongst upper middle class Manhattanites, I can assure you, blonde hair is rather strongly sex-linked. Additionally, I’m always struck, when I visit parent-child events at my daugher’s private school, by how the mothers are so much blonder than the daughters, which I guess lends empirical support to the dying-out theory.
Chris 03.05.06 at 8:25 pm
When you say lie detection, I suspect you mean the cheater detection module that is the cornerstone of EP in the cognitive realm. It’s not Pinker’s, it’s Cosmides’, and while it sounds very plausible, there’s actually no experimental evidence for it whatsoever. It sucks when your best hypothesis spends almost 20 years in the literature and still can’t garner any evidence.
neil 03.05.06 at 9:04 pm
It’s the newspaper who is responsible for the misleading blonde emphasis starting off with the leader “Cavegirls were first blondes to have fun”. Reading the article one finds that Frost is actually putting forward an argument for colour polymorphism – “Human hair and eye colour are unusually diverse in northern and eastern Europe (and their) origin over a short span of evolutionary time indicates some kind of selection,”.
It’s not quite true that Frost is putting forward the argument that “harsh environment selected for colour polymorphism”. Rather, the harsh environment was the cause of sex selection pressures for the polymorphism.
John’s alternative explanation does not explain the key issue – the variety of hair colours. Many inhabitants of cold climates have dark hair and show less hair colour variety. And I don’t think that just because males have blind hair is really a case against blondness being an indicator of oestrogen in woman.
Sebastian Holsclaw 03.05.06 at 9:15 pm
“I visit parent-child events at my daugher’s private school, by how the mothers are so much blonder than the daughters, which I guess lends empirical support to the dying-out theory.”
That is probably more indicative of the dyeing out theory.
John Emerson 03.05.06 at 9:24 pm
Let me agree with Sebastian for the second time in the last few years.
I grew up in the blondest area in the US, and when I visited Manhattan at age 16 I quickly realized that Manhattan blondes and farm-girl blondes are two completely different, almost-entirely-unrelated kettles of mackerel.
Tom T. 03.05.06 at 9:48 pm
I am a naturally blond man, and I have very large sex organs. I can’t help but think that the rest of you are overthinking this question.
P O'Neill 03.05.06 at 10:07 pm
If it was closer to April 1, I’d be suspicious about a story about blondes sourced to a “Peter Frost.”
non-expert 03.05.06 at 10:18 pm
I am by no means an expert in the field and I’m just throwing this out there. This theory seems to be consistent with how many blond boys grow up and are not blond as adults.
John Emerson 03.05.06 at 11:37 pm
One problem with Frost’s argument is that he had to come up with a reason why sexual selection was more powerful in NW Europe.
His caveman theory didn’t look poweful to me: high male mortality among hunters –> many helpless, parasitical women competing for the favors of a few men –> only the really hot women got laid –> ugly darkhaired women had fewer children.
It doesn’t really take a lot of male interest to keep a woman pregnant most of the time.
Particularly because
Sebastian Holsclaw 03.06.06 at 12:43 am
Did your wife cut you off?
chris y 03.06.06 at 1:50 am
It sucks when your best hypothesis spends almost 20 years in the literature and still can’t garner any evidence. Quoth chris, calmly placing EP on the same level of plausibility as ID.
Doug 03.06.06 at 3:35 am
Speaking of blonde jokes, there’s a good one here.
bad Jim 03.06.06 at 3:49 am
We could settle this if we could determine whether it’s true blondes have more fun.
My hunch is that higher latitudes permit variability in skin color and somewhat privilege lightness, with like effects on hair and eye color, but that their predominance in some northern European populations is chiefly the result of sexual selection, in either direction.
It might even be that popularity of blond hair is a side effect of the attractiveness of blue eyes, which are most common in light-haired groups.
bad Jim 03.06.06 at 4:00 am
On the other hand, blond hair is visible at a distance, and blue eyes are not.
derek 03.06.06 at 6:33 am
The vitamin D hypothesis loses a vital piece in most popular re-tellings: it’s not just the high latitudes, or eskimos would be blond. It’s high latitudes plus a move from hunting to farming. The two places to get vitamin D are eating animals and getting lots of sun: either alone would be sufficient, it takes the absence of both to put strong selective pressure on a dark-skinned northern population.
Note that poor children got rickets in nineteenth and early twentieth century industrial England, and it wasn’t because the rich children were whiter. It was because they were getting a better diet.
derek 03.06.06 at 6:41 am
To the commenter who said genetic drift would eliminate the “blond” allele from the human gene pool: I doubt it. We’re just too big now, it takes a population bottleneck to really do that.
For instance, we have the sickle-cell allele in Europe, it’s just not as common as in Africa.
CKR 03.06.06 at 11:00 am
I notice that most (all?) of the commenters so far are male.
As a female, let me introduce a small bit of hard-headed science into this mix.
Ever since Darwin, people have been trying to figure out what makes for genetic success. Darwin and others came up with the idea of sexual selection, which has been interpreted as male selection of suitable females (the meme currently under discussion) or female selection of suitable males.
The former version was seen to be a projection of male scientists’ prejudices, but its replacement, partial or total by the latter version has not solved a number of evolutionary questions.
A recent issue of Science contained an article suggesting a game-theory alternative to the idea of sexual selection. (Sorry, I’ve discarded it and never did sign up for the online version.) This approach has the advantage of doing away with just-so stories like this one, which are unprovable and frequently reflective of the originator’s prejudices.
John Emerson 03.06.06 at 11:23 am
The theory also seems to assume that the norse were hunter-gatherers when they went North, but as far as I know they’ve always been an agricultural / herding people.
The present Eskimos moved into the Canadian Far North in historical times (Christian era). Before that they were in Asia, though still pretty far north. Curiosity of history: the Turks migrated from almost the same place during almost the same period.
tylerh 03.06.06 at 2:46 pm
CKR, here is the publicly available abstract.
Reproductive Social Behavior: Cooperative Games to Replace Sexual Selection
Joan Roughgarden, Meeko Oishi, Erol Akçay
Science 17 February 2006
Vol. 311. no. 5763, pp. 965 – 969
Brendan 03.06.06 at 3:44 pm
Kudos to tylerh for pointing me in the direction of that article. I was far too stupid too understand it, but luckily the author provides an explanation so simple even a moron like me can understand it, here:
http://www.calacademy.org/calwild/2005summer/stories/sexual.html
I’m not an expert (to say the least) but her arguments strike me as fairly devastating.
Crystal 03.06.06 at 4:14 pm
I’m impressed by how well Frost knows what life was like in the Ice Age. I’m also impressed by how well he knows Paleolithic European men’s tastes – which seem to be suspiciously similar to modern American men’s.
Yabba dabba doo!
neil 03.06.06 at 5:33 pm
Brendan said – “I’m not an expert (to say the least) but her arguments strike me as fairly devastating.”
maybe you might re-evaluate that after reading this thread – http://pharyngula.org/comments/594_0_1_0_C/
I can sort of see why some aren’t too keen on evolutionary psychology but to go further and attack sex selction is weird.
the artilce Bredan links to is filled with some very odd and not exactly scientific reasoning.
derrida derider 03.06.06 at 6:34 pm
“I have heard that since her husband died Lady ___’s hair has turned quite gold with grief” – The Importance of Being Ernest
And, yeah, its a common misunderstanding that recessive genes somehow tend to disappear because they are recessive. Google “Hardy-Weinberg Law”.
Ronald Brak 03.06.06 at 8:10 pm
I always thought that blondeness was simply an adaptation against parasites that is practical in places where you don’t need pigment to block out excessive sunlight. It makes it easier to spot fleas and ticks in hair and pluck them out. Blondes make good mates because you don’t have to spend so much time grooming them. I wrote a movie script about this called, “Blondes have less fleas,” but no one in Hollywood returns my calls.
maidhc 03.06.06 at 10:02 pm
One big difference between Europe, where people evolved blond hair, and Asia, where they didn’t, is that Europe was occupied by Neanderthals, who spent a much longer time living in cold climates than homo sapiens ever did. And some remains seem to indicate that the two species did interbreed.
I am aware that the theory currently in favour is that all the Neanderthals and all homo sapiens in Europe died out during the last Ice Age, and Europe was resettled from Asia afterward. But the blond Neanderthal theory would explain the distribution of blond hair pretty well.
Maynard Handley 03.07.06 at 1:41 am
“It sucks when your best hypothesis spends almost 20 years in the literature and still can’t garner any evidence.”
Oh for heavens sake, Chris, the evidence is everywhere around you.
Why do you think people are so much more obsessed with “welfare queens” and bureacracy horror stories than with the success of welfare and government? People seem quite willing to condemn a thousand to misery if it will prevent one from somehow gaining an unfair advantage.
ogmb 03.07.06 at 2:15 am
Re: brendan — I’m not an expert either, but Roughgarden seems to base her opposition to the sexual selection theory on the cost differences between egg and sperm (or egg and ejaculate, as she corrects it). This seems odd to me as most of the cost of childbearing for the female, especially among mammals, come during and after pregnancy. Roughgarden notes that 90% of mammal species are polygynous, but doesn’t seem to acknowledge the link between gestation cost and sexual selection.
Re: neil — This link does not seem to be in response to brendan’s article, but about a claim by Roughgarden that Darwin offered an argument against homosexuality.
PS It’s also interesting to note that Joan Roughgarden was born John Roughgarden.
Brendan 03.07.06 at 4:19 am
Right ok. Now, the problem with Mr/Mrs/Ms’ Roughgarden’s article is that (since I don’t know much about the topic) s/he may well be creating a straw man (or woman…or…er….transgendered person of indeterminate ethnicity and…er….stuff).
Anyway! All I really know about sexual selection is Dawkin’s discussion of it The Blind Watchmaker and it all seemed very plausible then. But that was an example about physiology, not behaviour (it was the example of the peacock’s tail). Now Dawkin’s was using SS (Sexual Selection) as a way of explaining physiological phenomena that were not, apparently, in the organism’s (or the gene’s) interests to have. Now that I can swallow.
But look at Roughgarden’s arguments. What s/he is arguing against is the concept that sexual selection has an impact on high level behaviours, which is a whole other ball game.
In other words, you can have your cake and eat it. You can accept that SS explains many features of animal and for that matter, human physiology. And yes that, presumably, has some knock on effect on behaviour.
But to repeat, the idea that this then has an impact on psychology, let alone human psychology, is a far more dubious proposition.
neil 03.07.06 at 2:03 pm
ogmb,
the link was to show that in quarters regarded as authoratative on these sorts of issues in Crookedtimber land (PZMeyers) that Roughgarden is considered not particularly reliable. And her argument is not just about sexuality but attempts to debunk and replace sexual selection altogether and not just on the level of psychology, as Brendan believes, but on all levels including physiology –
“In social selection, the expensive tail on a peacock does not seduce a peahen. Instead, that tail is primarily a badge that earns the peacock membership in male power-holding cliques.”
It’s an odd statement from someone who is supposedly an ecologist – Peacocks don’t form those sorts of alliances with other males.
I can’t see how her alternative therory “social selection” can be anything other than Lamarckian.
The thesis that sexual selection influences behaviour/psychology can hardly be called “dubious” – it is either true in some instances or not. And in some instances it is. (In the case of hair clour Frost is arguing for teh reverse – that behaviour influences physiology).
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