A ten-year-old’s brain is not just growing. This is something that isn’t talked about enough in the field of pediatric health. There are ways to tell if it is already pulling back. Researchers working on the GUSTO study have been quietly making the case for that idea for the past ten years, even though it seems counterintuitive and even scary.
GUSTO stands for “Growing Up in Singapore Towards Healthy Outcomes.” It is one of Asia’s largest and most ambitious long-term birth cohort studies. It has kept track of hundreds of mother-child pairs from the time of conception until the child was born, gathering information at almost every developmental stage. Many people are interested in the study because it looks at kids between the ages of three and five. But we should have a serious conversation about what the data says about what happens a few years later.
An important finding from earlier in the study was that a mother’s mental health affects how she raises her children. This includes not only whether she is depressed but also whether she is truly emotionally healthy. And the way she raises her kids, especially when they are in preschool, has a direct effect on their IQ, vocabulary, math skills, and ability to make decisions. Researchers call this style of parenting “authoritative,” and it leads to significantly better cognitive outcomes. That part of the research is now pretty well established.
What’s scarier is what happens when those early advantages (or disadvantages) add up over time. When a child is younger than five, their cognitive development doesn’t just stop. It looks like kids who started school with lower vocabulary or executive function scores tend to have bigger gaps by the middle years of childhood. When a person is ten years old, they are old enough that early interventions have either taken hold or not, but still young enough that the window for real change hasn’t closed completely.
It’s possible that what researchers are seeing is less of a sudden decline and more of a plateau—a slowing of the fast cognitive gains that happen in the first five years of life, which feels like a step backward compared to what they thought would happen. Of course, the brain is still growing. But around this age, the scaffolding that was built in preschool starts to show its wear and tear. You can’t just ignore the cracks if the foundation was weak to begin with.
Associate Professor Helen Chen, one of the co-authors of the GUSTO study, made an important point: some of the kids in the study had behavior problems that didn’t go away as they got older. This was especially true for kids whose parents were more strict or more lax. They brought those habits with them to school. The exact link between these behavior patterns and cognitive ability at age ten and up is still not clear, but the link is hard to ignore.
There is an underlying message in the GUSTO findings that makes them useful rather than just worrying: a lot of this is not fixed. New research on the gut microbiome from other scientists suggests that what’s going on in the body outside the skull affects even brain aging, which was once thought to be a process that only happened in the brain. From a study on child development, that’s not the kind of hope you might expect. It says that there are more variables than was thought before, which means that there are more points of intervention.
As you look through the GUSTO data, you get the sense that science is finally catching up to what parents have always known to be true: that the first few years of a child’s life are very important and that what they bring into middle childhood is shaped by things that happen long before kindergarten. A headline about losing your mind at age 10 isn’t what science would have picked. But it might be the one you should pay attention to.
