Satoshi Kanazawa

The Scientific Fundamentalist

Barbie: Manufactured by Mattel, designed by evolution II

Why do men prefer to mate with young women?

Posted Sep 18, 2008


One of the major characteristics of ideal female beauty is youth.  Why do men prefer to mate with young women?

Men prefer young women because they have greater reproductive value and fertility than older women.  A woman’s reproductive value is the expected number of children that she will have in the remainder of her reproductive career, and therefore reaches its maximum at the onset of menstruation, steadily declines over her life course, and reaches zero at menopause.  Her fertility is the average number of children that she actually has at any given age, and reaches its maximum in her twenties.  Evolutionary psychological logic suggests that this is why men are attracted to teenage girls and young women, despite the laws of civilized society concerning the age of consent.  Remember, there were no laws against statutory rape in the ancestral environment; in fact, there were no laws at all.  The Savanna Principle, which states that the human brain has difficulty comprehending and dealing with entities and situations that did not exist in the ancestral environment, suggests that the human brain cannot really comprehend written laws, including laws regarding the age of consent.

For example, male high school teachers and college professors in the United States (but not their female colleagues) have a higher-than-expected rate of divorce and a lower-than-expected rate of remarriage, probably because they are constantly exposed to girls and women at the peak of their reproductive value.  Any adult woman they might be married to or date pales in comparison to their female students on the reproductive score.  This can also explain why most Hollywood marriages do not last very long.  Actors are constantly exposed to and closely associate with younger and younger generations of starlets, while their actress-model wives can only get older.

In this connection, here’s a little autobiographical aside, which nonetheless makes my point about the importance of youth in the ideal female beauty.  When Alan S. Miller and I first began writing the book Why Beautiful People Have More Daughters in 2000, we chose Pamela Anderson as the ideal of female beauty, the human Barbie doll, and we called the relevant section of the book “Why Do Men Like Pamela Anderson (and Why Do Women Want to Look Like Her)?”  As years went by, however, she ceased to fit the bill.  Baywatch went off the air in 2001, and Pamela Anderson turned 40 in 2007.  So we then chose to replace her with Britney Spears, who was at the time the perfect image of a virginal, nubile princess.  Well, you know what has happened to her lately.  Next candidate, please!

As we sought yet again to replace Britney Spears with another perfect image of female beauty, it eventually dawned on us that, no matter whom we would choose to use, she would be out of date pretty soon because of the high premium placed on youth for the ideal female beauty.  Had we written our book 30 years ago, the section would have been titled “Why Do Men Like Farrah Fawcett-Majors (and Why Do Women Want to Look Like Her)?” (except that evolutionary psychology didn’t exist 30 years ago so we would have nothing to write about in our book then!).  It would have made our book look really dated by now; Farrah Fawcett turned 60 in 2007.  Since we wanted our book to be read for a long time and don’t want it ever to look dated, we finally decided not to use an actual example of a blonde bombshell.