Recent research published in journals appetite This suggests that breastfed infants may develop better self-control skills by the time they reach preschool. The findings provide evidence that the act of breastfeeding helps babies recognize early and regularly that they are full. This daily habit tends to improve children’s ability to manage their impulses and behavior in later childhood.
Scientists designed this study to investigate how early life experiences shape a psychological concept known as executive function. Executive function refers to the basic mental processes that help people manage their thoughts, behaviors, and emotions to achieve specific goals. These mental skills develop significantly between the ages of three and five.
One specific component of executive function is inhibitory control. This is the ability to stop automatic or impulsive reactions to situations. Rather than acting on immediate impulses, people with strong inhibitory control are able to pause and choose a more appropriate action.
“For more than 30 years, our research has focused on the development of children’s self-regulation, their ability to manage their thoughts, emotions and actions,” said study author Sophie Jacques, associate professor in Dalhousie University’s Department of Psychological and Neuroscience.
People with stronger inhibitory control tend to have better health and economic outcomes in adulthood. “Because self-regulation is so important throughout the lifespan, many researchers (including ourselves) are working to identify early factors that may help foster these skills during development,” Jack said.
Research shows that babies who are breastfed have a lower risk of becoming obese as they grow up. Some scientists argue that this happens because breastfeeding acts as a natural training for appetite regulation. This theory suggests that breastfeeding teaches infants how to expend only the energy their bodies actually need.
When feeding an infant from a bottle, parents can see exactly how much milk is left in the container. Because of this visual cue, parents may mistakenly soothe the infant to drink even after the infant is full. “This may lead infants to rely on external cues, such as an empty bottle, rather than their own sense of fullness,” Jacques explains.
When breastfeeding directly, the mother cannot see the exact amount of milk consumed by the baby. As a result, breastfed babies rely on their own internal sense of fullness to know when to stop eating.
“In addition to regulating appetite, we thought breastfeeding might also provide broader ‘on-the-job training’ for self-regulatory skills,” Jack said. “Controlling food intake multiple times a day may help infants practice self-control more generally.”
To test this idea, researchers analyzed data from the Quebec Longitudinal Study of Child Development. This long-term project followed a large, representative group of children from infancy to childhood.
“The children in that study were born before breast pumps were widely used, giving us a unique opportunity to explore how history of breastfeeding relates to children’s development of self-regulation,” Jacques noted.
The initial sample included 572 infants. When the baby was 5 months old, and again at 17 months, mothers reported whether they were breastfeeding and for how long.
Using this information, scientists divided the infants into four specific groups. These groups included infants who had never been breastfed, infants who had been breastfed for less than 3 months, infants who had been breastfed for 3 to 6 months, and infants who had been breastfed for 6 months or more.
When the children reached 3 and a half years old, researchers visited their homes to assess their cognitive abilities. By this point, 491 children remained in the study to complete behavioral testing.
Children completed several direct assessments of their executive function. One of the tests was Luria’s Hand Game, which was specifically designed to measure inhibitory control.
In this game, an adult shows a child hand gestures such as making a fist or holding out a flat hand. Children are taught to do the exact opposite of what adults do. This helps children resist the automatic urge to imitate adults.
Another test of inhibitory control included a verbal task using pictures of the sun and moon. The children were shown a picture of the sun and asked to say the word “night.” When shown the moon, they had to say the word day.
Mothers also filled out questionnaires regarding their children’s daily activities. They assessed how often the child showed specific signs of hyperactivity or inattention over the past six months.
The researchers included several control variables in their statistical model to ensure their findings were as accurate as possible. These took into account family income, maternal education level, smoking and drinking during pregnancy, and maternal prenatal weight gain. They also took into account the child’s birth weight, gestational age, and general intelligence score at age 3.
Analyzes revealed that breastfeeding duration predicted improved inhibitory control at 3.5 years of age. Infants who were breastfed for at least three to six months performed better on the Luria hand game than infants who were not breastfed.
These children also reported less hyperactivity and inattentive behavior in their daily lives, according to their mothers. For example, mothers of breastfed children were less likely to report that their children were fidgety, impulsive, or had difficulty concentrating. Behavioral benefits were most pronounced in infants who were breastfed for more than 6 months.
Interestingly, only breastfeeding predicted inhibitory control. It did not predict other executive function skills, such as working memory or cognitive flexibility. Working memory involves holding information in your mind and updating it as you solve problems. Cognitive flexibility is the ability to change your thinking and see a situation from a different perspective.
The lack of association with these other skills supports the authors’ theory that breastfeeding specifically trains self-control. This suggests that nursing does not simply increase overall brain power, but also provides targeted practice in behavioral control.
Although this study provides interesting insights, there may be some misconceptions and limitations that should be kept in mind. The research team emphasized that the findings do not imply a causal relationship.
“Although we found a clear link between breastfeeding and children’s inhibitory control, it is important to emphasize that this study is correlational, meaning we cannot conclude that breastfeeding directly caused improvements in self-regulation,” Jacques explained. “It’s also possible that this relationship works in the opposite direction. For example, if an infant shows early difficulties with self-regulation, the mother is more likely to stop breastfeeding early or choose not to breastfeed.”
The authors also want to avoid leading to guilt or pressure regarding infant food choices. “Breastfeeding is not always possible or feasible for many families, and we do not want our findings to be used in a way that stigmatizes mothers and parents,” Jack said. “There are many medical, practical and personal reasons why mothers don’t breastfeed or stop breastfeeding sooner than planned.”
“Our paper suggests that breastfeeding infants directly makes it somewhat difficult, if not impossible, for parents to control how much their infants eat, compared to bottle feeding,” Jacques explained. “When bottle feeding, parents may want to focus on external cues, such as whether the bottle is empty.”
“But bottle-feeding doesn’t mean parents have to ignore their infant’s internal hunger and satiety cues,” she noted. “In fact, research shows that regardless of feeding method, some parents rely more on infant cues than intake.”
“The important point is not that bottle feeding is inherently problematic, but rather that it can benefit infants by allowing parents to pay close attention to their baby’s hunger and satiety signals and direct how much they eat,” Jack added. “Even when feeding from a bottle, infants can learn to regulate their intake if caregivers respond to these cues.”
Breast milk may also contain certain nutrients that help develop inhibitory control in the brain. For example, trace elements in breast milk may support general neurological growth in infants. Separating the chemical and nutritional benefits of milk from behavioral nursing practice remains a complex challenge for scientists.
Future research could investigate whether other infant routines provide similar self-regulatory habits. “More broadly, if our hypothesis is correct, breastfeeding is just one of many early experiences that may provide infants with regular opportunities to self-regulate,” Jacques said. “While long-term breastfeeding may offer a variety of benefits (including nutrition, parent-child interaction, and, as we suggest, repeated practice of self-regulation), it is not the only path.”
“The larger message from this study and others is that practice is key; the more opportunities children have to exercise self-control, the stronger their skills tend to become,” Jack says. “Experiences like learning how to self-soothe, developing sleep habits, potty training, and other guided tasks can help build inhibitory control that carries over into many areas of life.”
“These opportunities can take many forms across development,” she added. “Learning to wait for a reward, controlling eating from a plate, practicing a musical instrument, participating in team sports, and following the rules of school and group activities all give children opportunities to strengthen self-regulation.”
Researchers plan to continue exploring these developmental connections. “Our long-term goal is to continue investigating how psychological, physical, and health-related factors develop and interact over time,” Jack concluded.
The study, “Breastfeeding may provide in-situ training for self-regulation: Long-term links to inhibitory control,” was authored by Sophie Jacques, Sophie Parent, Natalie Castellanos-Ryan, Jean R. Seguin, and Philippe David Zelazo.
