Breastfeeding may provide on-the-job training of self-regulation: Longitudinal links with inhibitory control

Children who more effectively control their behavior on assessments of inhibitory control, a component of executive function, have better wealth- and health-related outcomes, including lower body mass index, suggesting that they may exert control across multiple contexts. Being breastfed also predicts later body mass index. One hypothesis is that breastfeeding provides regular practice at autonomous appetite regulation: Because mothers cannot gauge exact amounts of milk consumed from breasts, they may let infants use their own internal satiation cues to regulate consumption rather than rely on external cues (e.g., quantity of milk left in bottles). Indeed, multiple studies report that breastfed infants demonstrate better appetite regulation later on than bottle-fed infants. Beyond appetite regulation, however, breastfeeding may also provide early and regular inhibitory control training, more generally. To examine longitudinal associations, we conducted secondary analyses of data from the Québec Longitudinal Study of Child Development. When 572 infants were 5- and 17-month-olds, mothers reported on whether and for how long they breastfed. Children were later assessed on executive function and behavior, including inhibitory control assessed using both direct behavioral assessments and mother-reported hyperactivity and inattention (everyday indicators of poor inhibitory control). We found that breastfeeding during infancy predicted inhibitory control at 3.5 years of age, even after controlling for significant covariates, supporting the idea that breastfeeding may provide a natural means of introducing early and regular inhibitory control practice and that practice in one inhibitory control domain may promote improvements in other domains.