The Finch Formerly Known As Gold

6 August 2006

How I hate those mirrors

It's a boy, Mrs. Walker, it's a boy:

Good-looking parents are 36 percent more likely to give birth to a girl than less-attractive couples — which also explains why women are, on average, better looking than men, argues [Satoshi] Kanazawa, a professor at the London School of Economics and Political Science, in a forthcoming article in the Journal of Theoretical Biology.

Kanazawa based his conclusion on data collected during in-home interviews with 2,972 randomly selected young adults in 2001 and 2002. All were parents 18 to 28 years old, and they participated in the ongoing National Longitudinal Study of Adolescent Health. As part of the study, the interviewer rated the respondent's physical attractiveness on a five-point scale that ranged from "very unattractive" to "very attractive."

Kanazawa compared the percentage of boys and girls born to study participants who were very attractive with the sex ratio of babies born to everyone else. He found that 56 percent of babies born to beautiful parents were girls. For parents in each of the other categories, fewer than half of the babies — 48 percent — were girls.

But ... is there a reason for this?

[W]hy are beautiful people more likely to have girls? Kanazawa says scientists studying humans and other species have found that parents who possess any heritable trait that increases male reproductive success at a greater rate than female reproductive success will have more males than female babies, and vice versa.

Because men value physical attractiveness more than women do when looking for a mate, good looks increase the reproductive success of daughters much more than that of sons. So attractive people should have more daughters — which is exactly what Kanazawa found.

I note in passing that I have two children: a daughter and a son.

(Via Exploding Aardvark, with the following caveat: "A previous study by the same researcher [who incidentally used to teach here at the U of I] found that tall people are more likely to have sons. What happens with a tall, beautiful couple?")

Posted at 10:00 AM to Dyssynergy


What happens with a tall, beautiful couple?

Lucy Lawless.

Posted by: McGehee at 3:21 PM on 6 August 2006

There is an old wive's tale to the effect that "a daughter steals her mother's looks." In other words, having a daughter causes the mother to become less attractive. If there is any foundation to this folklore -- and, as the husband of a beautiful mother of three daughters, I am pleased to note that there is at least one exception -- then it could be that the researcher's data are accurate, but he has misinterpreted them.

Posted by: Sean Gleeson at 3:59 PM on 6 August 2006

As the father of three sons, I resemble that remark! But, I'm tall too. Glad we cleared that up.

Posted by: Jeff Brokaw at 4:57 PM on 7 August 2006

I'm not exactly short, except from here down [gestures], and both my kids are (1) way tall and (2) way cute. What's more, their kids are way cute, though it's kind of early to tell how tall they're going to be.

Apparently whatever genetic code produced my looks was as recessive as it was regressive.

Posted by: CGHill at 6:06 PM on 7 August 2006

Isn't the whole premise of the study flawed? It starts with a value judgment of attractiveness by the interviewer. Whatever happened to "beauty is in the eyes of the beholder?"

Posted by: Mike at 1:57 AM on 9 August 2006

Those who conduct surveys tend to consider themselves consistent and unbiased beholders.

Posted by: CGHill at 7:29 AM on 9 August 2006