Why women keep getting prettier

It’s natural selection: better-looking people have more girls

Why women keep getting prettierOn their 2006 album Boys and Girls in America, Brooklyn, N.Y.-based band the Hold Steady proclaim: “Guys go for looks, girls go for status”—an acute observation of a phenomenon, which, according to researchers, is having significant evolutionary repercussions. A new study shows that the importance that men, rather than women, place on beauty when choosing a mate is actually a form of natural selection. One result: women keep getting prettier, while men are as hairy and pudgy as they’ve ever been.

The University of Helsinki study is based on data collected in Wisconsin, which followed 10,000 high school graduates for four decades. Using the yearbook photos of a random sampling of 3,250 of the participants, researcher Markus Jokela asked a separate group of people to evaluate their attractiveness. On average, the women identified as attractive had 16 per cent more children than their plainer counterparts—a difference that was much less marked in men.

However, it’s not just the propensity of attractive women to have more kids that is pumping beautiful genes into the female pool. The fairer among us also tend to conceive more daughters than sons. In a government-backed study of 15,000 Americans, the most good-looking couples were 26 per cent less likely to have boys. Evolutionary psychologists Alan Miller and Satoshi Kanazawa explain this trend in in their 2007 book Why Beautiful People Have More Daughters. In part, the sex of a child is dependent, they argue, on the traits its parents have that are most beneficial to survival. And because being good-looking is a more significant factor in the reproductive success of women than men, it follows that pretty people would have more girls.

But while the recent findings might tempt men to settle into complacency about their looks, they would be wise to reconsider. Yet another study found that attractive women carry a hormone that makes them more likely to have affairs, and change partners if someone more desirable comes along.