In 2010, 6.2% of children in the US who were eligible to begin school were held back by their parents. The decision to hold a child back—often called “red-shirting,” a term borrowed from college sports—is often based on the parents’ belief that there are academic and emotional benefits from being old for your grade.
Parents appear to be particularly concerned about the impact on boys. More than 7% of boys are red-shirted, compared with around 5% of girls. College-educated parents are particularly prone to red-shirt their kids, specifically when they were born in the summer—more than 20% of college-educated parents hold back their summer-born boys.
This decision has some basis in research. Kids who are old for their grade do appear to be better off than younger ones.
A recently released working paper by researchers at the University of Toronto, Northwestern University, and University of Florida found that children born in August in the state of Florida—where the cutoff for starting Kindergarten is Sept. 1—have worse elementary school test scores, are less likely to attend college, and more likely to be incarcerated for a juvenile crime. The effect on test scores was particularly large.
This is not the first time researchers have found a strong “old for your grade” effect, but it is perhaps the best evidence yet. The researchers had access to a massive dataset on educational outcomes of nearly 1 million public-school students born in Florida between 1994 and 2000. Krzysztof Karbownik, one of the authors, says that this allowed the researchers to run a variety of tests to make sure the difference between August- and September-born children was not a result of factors besides age. A common concern about these types of studies is that parents with higher socioeconomic status may plan to avoid having children in the summer.
The researchers found that no matter how you crunch the numbers, September-born kids do better. Regardless of parents’ education level, income, or race, the difference in outcomes was always there, and about the same size. Even among siblings of the same parents, September-born kids did better than August-born ones, on average.
Given these effects, every parent should be red-shirting their kids, right? Karbownik doesn’t think so.
Although their research was not specifically designed to measure the effectiveness of holding kids back, he believes their findings suggest that kids held back by wealthy parents don’t see much benefit. “If a kid is really struggling or has some developmental disability, it would probably be beneficial to red-shirt them,” says Karbownik. “But if you are doing it to game the system, it’s probably not going to be very beneficial.” Also, the data shows that students who were not prepared for their grade are often held back anyway. That is, if your child needs to be held back, the system may do it for you.
There also serious potential downsides to keeping children from starting school when they are eligible. In a Brookings Institution report, economist Diane Schanzenbach and educator Stephanie Howard Larson note that children can be harmed by being too far ahead of their classmates. These kids are surrounded by students who are emotionally and physically less mature, and may have a difficult time relating to them. Like Karbownik, Schanzenbach and Larson think that the benefits of red-shirting only outweigh the drawbacks under unusual circumstances, such as a child who is facing emotional trauma or extreme developmental delay.
The moral of the story seems to be that summer-born kids are simply a bit screwed: holding them back won’t solve any problems, and might make matters worse. There has to be an age cutoff at some point for classes, and given that reality, some kids will end up worse off. Author Malcolm Gladwell, who has made the “young for your grade” problem one of his crusades, told 60 Minutes he thinks elementary schools with multiple classes should divide them up by birth month. That’s an action worth considering.