This is one of those claims that actually made me raise my eyebrows, you know, like “Listening to Mozart will make your baby smarter.”
It’s also the claim that I hear breastfeeding critics deride the most. So what’s the deal with breastfeeding and intelligence? Will breastfeeding really make your baby smarter?
Well, first of all let’s just acknowledge that intelligence is not really determined by any one thing. There’s been a lot of debate in the psychology world about whether geniuses are born or made, and the concensus now seems to be that it’s both. You really can’t boil down intelligence to something as simple as whether a baby was breastfed or formula fed. However, some studies have shown that babies who are breastfed have higher IQ’s than those who are formula fed. So what’s the deal there?
In 2015 a study from Brazil tracked a few thousand children born in 1982 for thirty years. They found that the ones who had been breastfed for 12 or more months had an average IQ 3.7 points higher than the ones who had been formula fed. (And they also earned 20% more as adults.) A caution is in place with this study though: it was not controlled for socioeconomic factors. Women with higher levels of education are more likely to breastfeed and that could skew the findings.
Also the PROBIT study (one of the largest and longest lasting breastfeeding promotion studies ever conducted) found that children in the group that had higher breastfeeding rates also had higher scores on IQ tests than the children in the group with lower breastfeeding rates. The conclusion of researchers was that breastmilk is the best nutrition for optimal cognitive development for children. Though that is kind of a given because children are biologically programmed to consume breastmilk and not cow’s milk, which means it’s just the optimal food source for them in every way.
The subject of intelligence and breastfeeding continues to be fraught with complicated answers. A 2012 study from researchers at Ohio State examined sibling pairs where one child was breastfed and the other bottle fed and found that there were no significant differences in IQ.And this stands to reason since the children were raised in the same environment and would receive the same levels of interaction and encouragement from their parents. Again, intelligence is a complicated thing. There are no “silver bullets”.(However the claims that this study proves that breastfeeding benefits are “overstated” are not accurate since this study looked primarily at complicated outcomes like intelligence, behavior and bonding which all have many influences and didn’t measure rates of viral or bacterial illnesses.)
If you want my opinion, I would say that breastfeeding can certainly contribute to your baby’s cognitive development in many positive ways, but you can have a very intelligent child even if you formula feed. (If we’re going to talk about benefits of breastfeeding, let’s talk about the remarkable disease protection breastfeeding confers. The results on that are a whole lot more concrete and direct. Or the fact that it saves families and taxpayers money from reduced costs of feeding and fewer sick babies.)
But whether you formula feed or breastfeed, here’s another interesting way to look at the issue: How important is a really high IQ score? IQ scores measure how well a child is expected to do with school work. Your child can have an average IQ and still be very successful. In her landmark book Gifted Children: Myths and Realities, Ellen Winner points out that William Schockley (inventor of the transistor) and Luis Alvarez (Physics Nobel Prize recipient) were both rejected from the prominent Terman study on gifted children because their IQ’s were too low. (None of the children accepted into the study won a Nobel Prize).
So if you’re breastfeeding because you think it will make your kid a genius, you’re missing the mark. Breastfeeding supplies optimal nutrition for a baby and may contribute to good cognitive development and a little higher IQ. But it won’t make your baby “smarter” and there’s more to intelligence than IQ.