I’ve been skeptical of the trend of “holding back” children with late birthdays. These are kids, usually born in the summer, who are just a few months short of the next grade cut-off. Some parents wonder whether it would be wise to hold them back a few months, so they end up one of the oldest (rather than youngest) kids in their class. This might seem to confer an advantage in terms of maturity, academic ability, and physical size, strength and coordination. Since children usually continue tracking up yearly, without later switching grades, kids “held back” in kindergarten will end up perhaps bigger and stronger and faster when trying out for teams in high school. A good idea?

Recent research has shown some stark differences in children who end up as the youngest versus the oldest kids in a classroom, which gives support to the idea of re-considering firm birthday-based rules for choosing when to start kids in school.

One good study was performed by researchers collaborating in Boston and Iceland. They looked at a nationwide cohort of Icelandic children, about 12000 kids, specifically grouping them by both birthdate and grade in school. Some findings from the study:

• Mean test scores were lowest among the youngest children, especially in early grades. This gap lessened by middle school, but was still significant.
• Children in the youngest third of a class were about 50% more likely to be prescribed medication for ADHD than kids in the oldest third of the class.

Similar findings have been reported by other researchers — this seems to be a real effect. Lumping children together by age creates a disparity in abilities within a classroom, with the youngest children being put at a relative disadvantage. That seems to create a greater likelihood of medical diagnoses and treatment for attention deficit disorder. It’s not known if holding back these younger kids with ADHD would allow them to become better students without fulfilling an ADHD diagnosis.

I’m not certain what the best approach is, here. Some kind of division between grades is inevitable, and some kids in any group are going to be the youngest. Perhaps smaller classes with a smaller age-range of children would help; or, perhaps an individualized approach to determining which kids will do best to start sooner versus later would address this disparity. In the held-back year, children who weren’t ready for school could get extra help with their attention abilities and other skills that will help them advance.

However, this could lead to other problems later on, when kids of greatly varying age (and therefore physical and sexual maturity) are mixed together.

I don’t have a solution, but it seems like this is a genuine problem. We’d better figure out a way to work this out that doesn’t depend on more medications for the youngest kids in a grade.

Roy Benaroch is a pediatrician who blogs at The Pediatric Insider. He is also the author of Solving Health and Behavioral Problems from Birth through Preschool: A Parent’s Guide and A Guide to Getting the Best Health Care for Your Child.