The Science of Large Breasts, and Other Evolutionary Verities

I blogged nearly a year ago about a study by the evolutionary psychologist Satoshi Kanazawa which argued that beautiful women sometimes marry unattractive men because of the following supply/demand gap: there are simply more good-looking women than there are good-looking men. One reason, Kanazawa said, is that beauty is a more valuable trait for a female, and is therefore accentuated in females via natural selection. Kanazawa and Alan Miller have now co-authored a book called Why Beautiful People Have More Daughters: From Dating, Shopping, and Praying to Going to War and Becoming a Billionaire — Two Evolutionary Psychologists Explain Why We Do What We Do, to be published in September.

First of all, whoo!, long subtitle.

Second of all, there is a sizable excerpt of the book in the current Psychology Today, which includes ten bite-size “politically incorrect truths about human nature” that make the book sound like a blend of Why Do Men Have Nipples, Survival of the Sickest, and maybe … Mad magazine?

Here are the ten topics:

1. Men like blond bombshells (and women want to look like them);

2. Humans are naturally polygamous;

3. Most women benefit from polygyny, while most men benefit from monogamy;

4. Most suicide bombers are Muslim;

5. Having sons reduces the likelihood of divorce;

6. Beautiful people have more daughters;

7. What Bill Gates and Paul McCartney have in common with criminals;

8. The midlife crisis is a myth-sort of;

9. It’s natural for politicians to risk everything for an affair (but only if they’re male); and

10. Men sexually harass women because they are not sexist

In the excerpt, some of the explanations are far more compelling than others. I will chalk this up to the limitations of excerpting. Here, for instance, is Kanazawa and Miller’s explanation of why men like large-breasted women:

Until very recently, it was a mystery to evolutionary psychology why men prefer women with large breasts, since the size of a woman’s breasts has no relationship to her ability to lactate. But Harvard anthropologist Frank Marlowe contends that larger, and hence heavier, breasts sag more conspicuously with age than do smaller breasts. Thus they make it easier for men to judge a woman’s age (and her reproductive value) by sight-suggesting why men find women with large breasts more attractive.

Large breasts as a helpful indicator of age? Really?

I would think that, even during the Stone Age, if a man had to resort to judging a woman’s age by the relative sag of her breasts instead of a number of other signifiers, he probably wasn’t the kind of fellow who was going to successfully reproduce anyway.