As T.S. Eliot might have said if he had a sunnier disposition, August is the blondest month.

It's late summer, so this will be a light piece on a topic—light-colored hair - that tends to generate more heat than light. Remember all the rage that Peter Brimelow elicited by mentioning, just once in Alien Nation, that his son had blond hair (even though he was making an undeniable point, about the negative impact on the non-minority native-born of immigrants being eligible for affirmative action quotas, that Hugh Davis Graham later expanded into his book Collision Course).

It's difficult to study hair color scientifically because it keeps changing. Whites are at their blondest right now because of the lightening effects of sunshine - and swimming pool chlorine.

Further, hair dyes are constantly improving, allowing ever-darker women (and some misguided men) to follow the advice of the famous 1960s Clairol commercial—"If I have only one life to live, let me live it as a blonde!" One study found that five out of every six blonde American women had some chemical help.

Back in the 1930s, Hollywood blondeshell Jean Harlow ended up wearing a wig because she'd reduced her real hair to a brillo pad by constant peroxiding, according to Joanna Pitman's informative new book On Blondes. Today, though, dyes have become so sophisticated that more than a few young non-whites have gone blonde in the last few years.

There are huge differences in hair dye consumption around the country. A decade ago, when I was in the marketing research business, I did a study that showed that among the twenty biggest cities, the least hair dye is bought by Boston women, presumably due to city's Puritan, Irish Catholic, and academic tendencies. In contrast, Dallas women, with their Southern belle and corporate orientations, buy the most.

Hollywood, which knows a lot about this subject, believes that gentlemen prefer blondes. For example, as Diana Moon has pointed out, the marketing of the Oscar-winning movie Chicago treated Renee Zellweger, a blonde who's a little funny looking, and Catherine Zeta-Jones, a brunette with classic features, as if they were equals in beauty. "The bar is set higher for brunettes," Moon said.

The press typically attributes the popularity of blondeness to the evil monopoly of the WASP elite (or whatever). But that doesn't make much sense because there's little demand for blond men. Hollywood, for example, believes that ladies prefer their gentlemen tall, dark, and handsome, a phrase coined by Mae West about Cary Grant. There are dramatically more blonde actresses than actors, because audiences apparently associate darker hair with mature masculinity. In the vast majority of love scenes in movies, the man is darker in hair and skin color than the woman. Actors typically described as blond, such as Leonardo DiCaprio, generally wear their hair much darker than do blonde actresses, such as Meryl Streep or Kate Hudson. Even Conan the Barbarian was played as a brunet by Arnold Schwarzenegger.

This pattern appears to be true around the world. Latin American television, for example, is full of blonde women and darker Latin lover-type men.

Why do gentlemen prefer blondes - or at least take more notice of them? My guess is that it's largely because blonde hair is inherently more noticeable. Women like to wear gold and silver jewelry for the same reason—it makes them, to put it crudely, shinier. (In fact, as anthropologist Peter Frost has pointed out, women of all races tend to have shinier, lighter-colored skin than their menfolk—that's why they're traditionally called "the fair sex.")

Men tend to be attracted to women who look like they want to be attractive to men, because it saves everybody a lot of time. For natural blonde women, this can be a blessing and a curse. One natural blonde woman told me: "My hair acts like a flag to men, which is great if I'm in the mood for attention, but it's not if I'm not."

Natural blondes are found among certain Australian Aborigine bands and of course among Caucasians. The Berbers of the Atlas Mountains of Morocco and Algeria possess a surprising degree of blondeness. (The most famous Berber is soccer star Zinedine Zidane—he's not quite blond, but he could easily be mistaken for a German.) Relatively fair-haired people can be found as far east as Afghanistan and the mountains of Pakistan.

Most blondes, however, come from Europe. There is a general "cline" of increasing blondeness from south to north, although the Lapps of the extreme north are quite dark haired. The highest proportion of blondes is found in the Eastern Baltic region, but nowhere is everybody blonde. In the west of Europe, blondes tend to be golden in color and in the east of Europe, you are more likely to find ash blondes.

Why do Caucasians differ so much amongst themselves in hair color, while everybody else (with the exception of some blond Australian Aborigines) has dark brown hair?

Here's my theory, but it's only a theory.

Blonde and red hair are favorable mutations for women because they make men notice them more. Fair hair reflects more light than dark hair, so it catches the eye more.

In The Descent of Man, Charles Darwin called this kind of mechanism that makes a person more attractive to the opposite sex "sexual selection." He argued that it was the main engine of the human race's striking racial diversity.

It was a brilliant insight, one that took the rest of the scientific world more than a century to start taking it seriously.

Still, sexual selection can't fight too strongly against natural selection. You can't be a ladies' man if you are dead. And that may explain why blonde or red hair never became universal anywhere. First, it would lose some of its scarcity value if all women had it. But, also, while it's good for your daughters, under pre-modern conditions it was bad for your sons. It tended to hurt males at hunting and war.

The problem is that you can see blondes from farther away—at a golf tournament, I once recognized the ultra-blonde champion Greg Norman from 500 yards off just from the sun glinting off his near-platinum hair.

It didn't hurt Norman's golf career that his hair catches the eye from more than a quarter mile away. But for one of his Norman ancestors on a hunt or a raid on a sunny day, it could have ruined the element of surprise. Of course, in the Nordic homelands of the Normans, there weren't many bright sunny days. 

Thus, blonde hair becomes more common the farther in Europe you go north, where the sun is low in the sky - Europe is at a much higher latitude than any other heavily populated region - and the land heavily forested and shady. Within Northern Europe, red hair becomes more prevalent the farther west you go, where, due to the Gulf Stream, the weather is extremely cloudy and misty. So, in Northwest Europe, you can have lots of blondes and redheads because lack of strong sunlight meant that shiny hair worked well for women, without much penalizing their men folk when hunting or raiding.

Are blondes dumb?

Speaking very roughly, the blonder the country, the more Nobel Prizes it wins per capita. Northern European nations score well on IQ tests, although not quite as high as northeast Asian countries.

Of course, the dumb blonde jokes are aimed at blonde women (frequently by non-blonde women). And the vast majority of blondes are dyed.

Women who go through all the upkeep of being bottle blondes are upping the ante in the sexual attractiveness arms race. It's natural for other women to make nasty jokes about them. Similarly I often write uncomplimentary things about men who use steroids  and artificial testosterone, such as Arnold Schwarzenegger and Andrew Sullivan, because I'm against this kind of masculinity arms (or in this case, biceps) race.

So don't expect any ceasefires in the Blonde Wars – regardless of immigration policy.

[Steve Sailer [email him] is founder of the Human Biodiversity Institute and movie critic for The American Conservative. His website www.iSteve.blogspot.com features his daily blog.]