First the great line. Emily, thanks for putting a whole new twist on the pressure to breastfeed. I would never have thought this is possible: "They asked mothers about whether they'd breast-fed via questionnaire".

I live in Berkeley, CA, one of the hyper-pressurized breastfeeding locations in the country. My children were all breastfed (including my twins who were breastfed exclusively for 6 months and then weaned at about 13 months). I am happy and proud that they were and that my spouse and I were able to experience that. Who knows whether each is 7 IQ points smarter than they would otherwise have been. They are pretty smart but I am their parent so take what I say with a grain of salt. Also, who knows if they are healthier than they would otherwise be. We have had our share of infections and fevers. My point is that it seems natural, was always there and just felt right. That is fortunate, living where we do, because there are times when that is not the case for parents. And, too many people feel like they need to tell the parent of the baby that they are making a wrong choice.

Anecdotally, one of the smartest and healthiest kids (in fact, this high school sophomore has yet to miss a day of school) I know was not breastfed (nor were this kid's siblings). Their parents are just as loving and sacrafice just as much as any of the best parents I know.

My point: Make your decision about breastfeeding based on what works for you, considering the factors you think are most important. If the decision works for you, it should work for everyone else.

How did they control for maternal IQ if they used questionaires? Did people self-report their IQ? What about paternal IQ?

What was their response rate?

A recent study in English showed the entire variation in IQ between breastfeeding and non-breastfeeding children was explained by parental IQ. The average IQ of the parents of breastfed children was 15 points higher (an entire standard deviation). Probably because breastfeeding is an ideological quirk of the educated.

And, of course, this study assumes IQ actually measures something. Which most evidence suggests it doesn't.

My question about all of these studies, which often rely on statistics about "this" and "that". The biggest problem I always see is that most the media neglects an important fact: most of these studies show correllation, not causation. The two concepts are NOT the same. In fact, relying on correlation to draw conclusions can lead to some huge mistakes in logic. For example, if more white men with brown eyes are serial killers, does that mean that white men with brown eyes have predisposition for serial murder? No, it just so happens that: most killers are men, people in this country are white and most white people have brown eyes.

So, do kids with higher IQs get breastfead? Do families with higher IQs breastfeed more? Do families that breastfeed more have better diets, leading to healthier kids and higher IQs?

In the end, I think to come up with these "ancillary" benefits for breastfeeding miss the point entirely. Breastfeeding is better, generally speaking, because breastmilk is better for kids than formula. However, that doesn't mean that kids are "unhealthy" and "deprived' if they don't breastfeed, it just means that they don't have all the benefits imbued by breastmilk.

Looks like we posted the same argument simultaneously. Thank you for being more succint than me on this point!

I never even knew it was possible to breastfeed via questionnaire.