Your kids might already be set apart from the moment they’re born. And no, this isn’t about nature versus nurture—it’s about how the month you’re born in shapes your future. The National Bureau of Economic Research tackled the big question: Which month is best to be born?
The study looked at grades of students aged 6 to 15 and found that kids born in September—the most common birth month—scored higher on average than their classmates.
Researchers used equations to predict kids’ future grades and college success. Unsurprisingly, they found that high-achieving students tend to score better on tests, get into better schools, and are less likely to face legal troubles later on.
This isn’t about zodiac signs—Virgos and Libras aren’t the smartest stars anyway—but about how much older September-born kids are compared to their classmates when they start school.
Most schools set the birthday cutoff at September 1. Kids born that month are usually the oldest and most developed in their class. Meanwhile, August-born kids often lag behind because they’re younger than most of their classmates.
Why This Advantage Matters
Early on, those few months of extra development can make a big difference, since childhood growth happens in leaps. Over time, this advantage snowballs—kids born in September often get into better programs and enjoy higher-quality learning time. That boosts their brainpower, creating a positive cycle that builds on itself.
Of course, parents of July or August babies don’t need to worry. Beyond birth month, many factors shape how well a child does in school. While September-born kids statistically start with a slight edge, individual success depends on so much more—so don’t plan your family calendar around this alone.
Why Are Most Babies Born in September?
Besides the school advantage, September is also the most common birth month. This likely ties back to increased intimacy during the holiday season nine months earlier. Seasonal shifts in fertility, influenced by temperature and weather changes, also play a role.
Cover photo: AleksandarNakic/istockphoto.com
