The study looked at children's cognitive development and mainly focused on expressive language, nonverbal reasoning and problem solving. We found that breastfeeding for at least 90 days versus less than that would shift a child up 15 percentile points in that distribution. By age seven, it appears that the effects are a little smaller and possibly fading out. But we need to study this further to really understand the longer term outcomes.
In this special episode of Freakonomics, M.D., host Bapu Jena looks at a clever new study that could help answer one of parenting’s most contentious questions.