Beauty Treatment: Unfair Hair

A blonde walks into a bar—and every patron passes a snap judgment of her. Are the stereotypes silly or sound? We examined the facts.

Stereotype: Gentlemen prefer blondes.

Since light hair usually darkens with age, men drift toward blondes as the hue is an indicator of youth (and mating potential). Blondness probably evolved in northern Europe's chilly climates where men couldn't see other fertility flags, like breasts, under winter layers, says Satoshi Kanazawa, a London School of Economics psychologist and PT blogger.

Verdict: Sorry, raven-haired beauties—the cliché seems to be rooted in truth.

Stereotype: Blondes are dumb.

The airhead trope likely stems from the tendency (described above) for blondes to grow darker with age; if true blondes are young, they're probably also less wise. But Kanazawa suspects towheads are smarter than non-blondes: Because fair-haired females are more desirable, "more intelligent men, with higher status and greater resources, should marry blondes—and their children should simultaneously be blonde and intelligent," he says.

Reliable data on natural hair color are hard to come by, though. One survey, Add Health, which only tracks apparent hair color, found that, among white non-Hispanics, blondes had very slightly lower IQs than others. (Blame the bleach?)

Verdict: Like, oh my gosh—the jury's totally still out. —Kasia Galazka

Lustrous Locks

These products will make your hair gorgeous, regardless of its hue.

• VO5 Hot Oil Moisturizing Treatment

  This tiny tube of oil, slathered on before shampooing, leaves tresses buttery soft after only a minute.

• Bumble & Bumble Styling Lotion

  Spritz this crisp-smelling formula on damp hair before heat-styling for a shiny, brittle-free hold.

• Fekkai Large Round Brush

  This luxe, high-quality brush turns tangles into a smooth and bouncy blowout.

Tilt of Attraction

How evolution shaped your face

The facial dimensions of pretty women and handsome men are more different than size dimorphism alone would predict: Women are larger from the ear up and smaller from the ear down (picture a heart-shaped face), while men show the opposite pattern (strong jaws and smaller foreheads). Why?

"We thought sexual selection might explain it," says Darren Burke, a psychologist at the University of Newcastle in Australia. His hypothesis: Heart- and pear-shaped faces emphasize the height differences we also prefer—shorter women, taller men. A top-heavy visage, they reasoned, emphasizes a seen-from-above perspective, while a big jaw emphasizes the from-below view. Their research, published in Evolutionary Psychology, supports their claim: Subjects rated tipped-down female faces as more feminine and pretty, while men's faces got a masculinity and hotness boost from an upward tilt.

"Sexual selection exagger-ated the differences that gave people an advantage," Burke explains. —Andrea Bartz