Is It Better To Be The Oldest Kid In Kindergarten Or The Youngest? Here’s What The Data Says

When you have the option to push your kid or hold them back a year, here’s what experts say is best.

The day I realized it, I briefly lost my mind. I asked the director of my son’s preschool when he’d move into the Brown Bears class from Yellow Ducks, and she said, “We go by the school district’s cutoff date of October 1, so not until next year.” Cutoff date? We’d moved to the suburbs from New York City, where every kid who is turning 5 that year goes to kindergarten, period. My son was barely 4, so I hadn’t yet learned that in our school district, a kid with an Oct. 3 birthday starts kindergarten at damn near 6 years old. In some towns, you can appeal this; in ours, no exceptions are made.

I learned these district rules in the preschool parking lot that morning, furiously Googling to make sure I understood: Yes, we would be on the hook for an extra year of daycare (around $20,000) and thus for an extra year of me working full-time (I’d planned to go freelance once he went to kindergarten) — and someday, perhaps, for an already-18-year-old man seething with rage that he had to live at home another year. Driving home, I screamed, “F*ck!” so loudly the windshield shook.

Then came the panic spiral. What if my kid got deathly bored in kindergarten, having already learned what a rhombus is and how to spell his name, and what if that boredom turned into long-term antipathy for school, which became chronic bad grades, which morphed into a general disillusionment with learning that wrecked his self-esteem and kept him out of college and caused him to never find a sense of purpose? What if my kid being born two days after a small New Jersey town’s arbitrary bureaucratic ruling had destroyed his life before it began?

Yes, I am a worrywart (why do you ask?), but in my defense, research shows that there are consequences when a kid starts school either considerably younger or older than their classmates. It’s just that I can’t tell which option is better, because the research is maddeningly contradictory. For example, a 2009 study found that kids who are younger than their peers do better in school because they rise to the maturity level and academic ability of the kids around them. But another body of research — famously explored in Malcolm Gladwell’s bestselling book Outliers — indicates that holding a child back a year lets them develop emotional control, social ease, and a stronger base of knowledge, helping them excel academically. A 2009 study showed that older kids in a class are held back a grade and diagnosed with ADHD far less often than their younger peers. For years, parents have been holding their kids back a year before kindergarten — a practice known as “redshirting” — to buy them these very advantages.

Taken all together, this research would seem to be a win-win — my kid will be A-OK either way! — except that there are flipsides to both findings. A 2021 study out of Finland indicated that younger kids in a class are more likely to be diagnosed with learning disorders, potentially because their developmentally appropriate abilities are being judged against those of older kids. But it’s no picnic for older kids, either. If the younger kids in their class are disruptive, as younger kids are more likely to be, the interruptions can have a detrimental effect. One 2018 study found that even one disruptive student out of 25 can bring down the entire class’ potential, reducing the other kids’ future earnings by 3-4%. Further, the big advantages that Gladwell and America’s well-meaning redshirters love to tout seem to dissipate quickly: By 9th grade, a redshirted kid will be no more than 7% more advanced than their classmates.

So, what to do? In our case, there was one option besides begrudgingly waiting until the following year. We could have our son spend two years at a private school, since their cutoff rules are less rigid; he would then be permitted to transfer to our local public school as a first grader. But that felt inhumane, shuffling him from his beloved preschool to a new school, then another new school. Our son is, shall we say, not someone who enjoys change. It takes him a while to warm to new things, but once he does, he thrives. The musical school’s approach seemed particularly ill-suited. (Nor would it spare us that extra $20K.) In the end, our kid is just going to be that extra-tall kid in the class photo, and we’re fine with that. If all goes well, he gets to be a kid for an extra year. If he’s bored out of his mind by second grade, we can revisit this and investigate moving him up a grade — this decision isn’t a one-shot deal.

Which brings me to another important point in this confusing equation: Ultimately you must do what’s best for your kid, not what academic studies recommend for some theoretical everykid. Some kids are precocious old souls who find being surrounded by older kids exhilarating and mind-expanding. Some kids are anxious and risk-averse and need extra time to fortify their inner resources before starting their decade-plus of mandatory education. To the extent that this decision is up to you — which, depending on your location, may be a little or a lot — know that the choice isn’t just about your kid being on-track or behind or ahead. It’s about the complex bundle of quirks and proclivities that make them who they are, and how you can help them succeed. The stats are useful, but they’re not everything. Or as Emily Oster, guru of parenting-related data, wrote in her newsletter on redshirting, “As with many things in this era of life, the data is a piece of the puzzle, but only one piece.”