Research Says the Month You Were Born May Determine Your Entire Life
A new study from the National Bureau of Economic Research confirms that yes, one particular birth month does reign supreme—but the reason isn't all that surprising when you think about it.
Astrological signs are fun, and occasionally revealing. But your star sign or birth month flower isn’t the only important thing about your birth month. Imagine this: the difference between being born in one month and the following month can impact IQ and test scores in school, how likely you are to attend college, even how likely it is that you’ll be incarcerated. This data comes, by the way, from the nonprofit research center the National Bureau of Economic Research.
So what’s the big change between one month and the next? It’s all about school cutoff dates. The NBER undertook a huge study in Florida, where the cutoff date—deciding who ends up in which grade—is September 1st. It may not seem like a big deal, but school cutoff dates effectively make some students a full year older than other students in their grade, and being older for your grade can have huge, lasting advantages for kids.
The research focused on kids born in August and September, which, in Florida, would then make the youngest and the oldest kids in their grade, respectively. And the researchers found statistically significant differences. Those born in September scored consistently higher on standardized tests, even within the same family, than those born in August. The benefits continue later in life, too, perhaps a snowball effect from early achievement in school.
Children born in September are 2.1 percent more likely to go to college, 3.3 percent more likely to graduate from college, and 7.2 percent more likely to graduate from a competitive college than August kids. September kids are also 15.4 percent less likely to end up in a juvenile incarceration facility than August kids.
There are a few ways families try to take advantage of these statistics. Parents can sometimes “redshirt” their kids—hold them back, so that they’re older for their grade—or they simply try to plan pregnancies to give birth in the early fall. The research found that kids from white, privileged families are most likely to do this. But the benefits of being old for your grade don’t seem to be affected by race or socioeconomic status: all kids do better when they are older for their grade.
The cutoff dates vary by state; September 1st and August 1st are common, though some states break from the mold (Connecticut’s date is January 1st, in a fit of literal thinking) and others allow for more wiggle room.
Obviously, there’s nothing objectively good about this kind of advantage, but with school set up the way it is, there’s no clear solution. Here’s the positive way to think about it: if you were old for your grade, nice! You got lucky. If you were young for your grade? Congratulations on overcoming the odds to become who you are today.