Why do blondes have more fun? Because gentlemen prefer blondes. Why do gentlemen prefer blondes? Because they have evolved psychological mechanisms that predispose them to prefer women with blonde hair. Why?
The notion that blonde hair is the female ideal goes back at least half a millennium, possibly two millennia. There is evidence that women during the Roman era and the Renaissance period dyed their hair blonde, long before the discovery of peroxide in 1812. Women desired to be blonde so strongly throughout recorded history that they accomplished it without the aid of peroxide.
Some believe that men prefer blonde hair because blonde women tend to have lighter skin, which they prefer. But this seems to be false. While men do prefer women with lighter skin color, because it is an indication of higher fertility (a woman’s skin color darkens when she is pregnant or on the pill), the lightest skin color is associated with red hair, not blonde hair; yet, according to one study, both men and women have extreme aversion to potential mates with red hair. It turns out that men prefer blonde hair for exactly the same reason that they prefer large breasts: both are accurate indicators of a woman’s age and thus reproductive value.
What distinguishes blonde hair from all other hair colors is that it changes dramatically with age. Young girls with light blonde hair usually grow up to be women with brown hair (although there are a very few women who retain their light blonde hair into adulthood). Thus, if men prefer to mate with women with blonde hair, they are unconsciously attempting to mate with younger (and hence, on average, healthier and more fecund) women with greater reproductive value and fertility. It is no coincidence that blonde hair evolved in Scandinavia and northern Europe, where it is very cold in winter. In Africa, where our ancestors evolved for most of their evolutionary history, people (men and women) mostly stayed naked. In such an environment, men could accurately assess a woman’s age by the distribution of fat on her body or by the firmness of her breasts (as I discuss in a previous post). Men in cold climates did not have this option, because women (and men) bundled up in such environments. This is probably why blonde hair evolved in cold climates as an alternative means for women to advertise their youth. Men then evolved a predisposition to prefer to mate with women with blonde hair in response; those who did on average had greater reproductive success than those who did not, because, unbeknownst to them, they ended up mating with younger, healthier women with greater reproductive value and fertility.
Incidentally, this also suggests that the stereotype that blondes are dumb may have some statistical basis and is true (as virtually all stereotypes are true, as I explain in a previous series of posts: I, II, III, IV, and V). Why do people believe that blondes are dumb? Recall that the human brain, including the stereotypes that it generates, is adapted to the ancestral environment (as the Savanna Principle suggests). What would be the average age of light blondes in the ancestral environment (say, northern Europe 10,000 years ago) in the absence of hair dye? Roughly 15. What would be the average age of brunettes in the same environment? Roughly 35. A 15-year-old woman is bound to be more naïve and less experienced, mature, and wise (in other words, “dumb”) than a 35-year-old woman, no matter what her hair color. It’s not that blonde women are dumber than brunette women; it’s that younger women are “dumber” (less knowledgeable, experienced and mature) than older women, and blonde hair is a reliable indicator of extreme youth.
The same logic is probably behind the stereotype that women with large breasts are dumb. In the ancestral environment, without plastic surgery or even bras, only very young women had large, firm breasts.