Does Breastfeeding Increase IQ?
The Myth: Breastfed children have significantly higher IQs than formula-fed children.
The Reality: Research shows a small IQ advantage (2-4 points) for breastfed children, but much of this is explained by maternal IQ and socioeconomic factors rather than breast milk itself.
What the Science Says
Early studies found breastfed children scored 3-7 IQ points higher than formula-fed children. However, more rigorous research has significantly narrowed this gap. A large randomized trial in Belarus (PROBIT study) found only a 2-3 point advantage for breastfed children — and even this was influenced by the fact that mothers who breastfeed tend to have higher IQs, more education, and higher socioeconomic status (all of which independently boost children's IQ). Sibling studies (comparing breastfed and formula-fed siblings within the same family) find little to no IQ difference, suggesting the apparent benefit comes from family environment rather than breast milk itself. That said, breast milk does contain fatty acids (DHA, ARA) important for brain development, and the close physical contact during breastfeeding may have developmental benefits. The honest conclusion: breastfeeding may provide a small cognitive advantage (1-3 points), but the effect is much smaller than claimed and largely confounded by socioeconomic factors.
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Frequently Asked Questions
Does breastfeeding increase IQ?
Probably by a small amount (1-3 IQ points), but much of the observed advantage is explained by maternal IQ and socioeconomic status rather than breast milk itself. Sibling studies show minimal differences.
How much does breastfeeding affect intelligence?
The best evidence suggests 1-3 IQ points at most, with much of this confounded by family factors. This is far smaller than the 5-7 points claimed in earlier, less rigorous studies.
Should I breastfeed for brain development?
Breastfeeding has many health benefits beyond any IQ effect. But if you can't breastfeed, modern formula provides adequate nutrition for brain development. The IQ difference, if any, is very small and shouldn't cause guilt.
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MyIQScores Editorial Team
Researchers in cognitive psychology, psychometrics & educational science
Last updated
May 10, 2026
All content on MyIQScores is reviewed for scientific accuracy against peer-reviewed research in cognitive psychology and psychometrics. Our editorial team cross-references each article with published literature before publication and updates pages whenever new research warrants a revision.