As the mother of three daughters, now all grown up, I always find conversations about the gender of one’s offspring interesting. Parents often argue about which is easier to raise–boys or girls. I’m not in any position to argue that one–plus, my girls have always been a pleasure to parent.

Mr. F and I got a big laugh out of Satoshi Kanazawa’s research that suggests that beautiful parents are 26% more likely to produce first-born daughters than sons (think Brad Pitt/Angelina Jolie or Tom Cruise/Katie Holmes or Ben Affleck/Jennifer Garner). I don’t know about beautiful, but Mr. F and I have always been amused by the overwhelming number of daughters born to his former shot putter and football playing buddies. Another group that seems to have a disproportionate number of daughters is Army generals. It’s almost like Mom Nature thinks she needs to tone down all this testosterone by making daughters instead of sons.

The latest offspring study to catch my eye is by Finnish biologist Virpi Lummaa, who just gave birth to a son herself. Lummaa has been studying Finnish church records from the 1800s, and offers the conclusion that giving birth to a son instead of a daughter reduces your lifespan by 34 weeks. Lummaa suspects that the larger size of male newborns plus the detrimental effects of testosterone on the immune system might account for this difference.

The mother of sons is not the only one who is affected. Siblings born after a son rather than a daughter are physically slighter, have smaller families, and have a higher risk of dying from an infectious disease. These outcomes have nothing to do with the behavior of the brother, because the same results occur if the son dies in childhood. These results are more likely to result from the impact of carrying a male fetus on the mother.

So, Kristin, Karen, and Karla, I guess I should thank you for being who you are and for those extra 34 weeks.


6 Comments

nichol.myers · October 18, 2007 at 9:02 am

I have always said that if I had birthed sons, I wouldn’t have survived — 34 weeks seems negligible by comparison! I do know from parenting experience that daughters are, by nature, more demure and less apt to receive injuries than boys are — this, to me, suggests that the stress load of a mother with boys would be astronomical.

I am very grateful I have girls, however they come with their own set of interesting “issues” : dealing with boys, going through puberty and that monthly mood-swing-business, clothes being of utmost importance over other life-important topics–like homework, learning to do their own laundry, getting a job! 😉 / However I wouldn’t trade it for anything. And, by the way, I think the research of more attractive people giving birth to first-born daughters is GREAT! I have only girls (and so do you!) so what does THAT say about our looks!

Laura Freberg · October 18, 2007 at 11:16 am

I was very impressed with how mature your daughter was when she came to class. Good job, Mom! As far as the beauty thing goes, we’ll try to stay humble 🙂

c.busso · October 24, 2007 at 2:34 pm

My mom also had three daughters. We were all relatively small babies, 6+ pounds, so this article made me wonder what the differences would be if she had a male baby. This article also made me think about the effects a boy would have had on my mom, she’s a nonstop mother but I think a boy would have slowed her down a bit. Also, the idea that it isn’t the behavior of the son, but the actual pregnancy sounds very different to me! You would think it was the stress that a child puts on the parents that would have an effect on the length of life.

cat tran · October 29, 2007 at 2:18 pm

Well, my mom wouldn’t be too happy about this, she’s had four boys! Would I say her life has been more difficult because of this? probably…but more so because of the reckless behavior of boys! And then there’s me, the youngest and the only girl…does that mean my brothers gave me a higher risk of dying from an infectious disease? well I’m still standing, healthy and alive! I probably shouldn’t tell my mom that my brothers may cause her at least 34 weeks of her life…I think she’s dealt with quite enough already!

nichol.myers · October 30, 2007 at 12:17 pm

Well put, Professor Freberg. I agree — humility is much more attractive on a person.

nichol.myers · October 30, 2007 at 12:18 pm

By the way, thank you very much for the compliment!

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