When should kids start kindergarten?

By Jessica Kelmon

This fall, four-year-old Luke will be starting kindergarten in Centerville, OH. He’ll be one of the youngest in his class — turning five just before the school year begins — and his mother is concerned.

Nationwide, the starting age for kindergarten varies widely. In states like Connecticut and California, you can easily find a four-and-a-half-year-old and a six-and-a-half-year-old in the same kindergarten class. That’s exactly what worries Luke’s mom, Deb Nelson, who has seen the difference just a few months can make, whether at home with her three sons ages 6, 4, and 3 or at school with the kids in her older son’s kindergarten class. Some kids are ready to read and write; others have trouble sitting still and paying attention. Being younger is particularly problematic as kindergarten becomes increasingly academic.

While there’s no statistical evidence that delaying kindergarten is on the rise, anecdotally it appears that more and more parents are doing it. But will this benefit or hurt children in the long run? Educators and parents are wondering just that, as they weigh the potential risks of starting kids in kindergarten when they're either much younger or much older than other kids in their class.

Why redshirt?

Nelson’s not only worried about kindergarten. "It’s junior high," she says. "I don’t want him to be 11 when everyone else is turning 12 and have him be practically a year behind everybody in sixth or seventh grade." Both concerns — for a child’s success in kindergarten and through adolescence — are driving forces behind the popular practice of "redshirting," or delaying a child’s kindergarten entry by a year or more. (The term is borrowed from collegiate sports, where athletes will practice with the team for the first year, but sit out competition while they get bigger, stronger, and more competitive.)

Parents typically hold a child back because they feel he isn’t ready — cognitively, socially, or emotionally. Others may want to give their child a leg up, on the assumption that being older will make him more advanced. "In a lot of circles, it’s become the fad," says Gary Painter, an associate professor at USC’s School of Policy, Planning, and Development, who authored a paper on redshirting. "Particularly in upper-middle-class circles where parents want to give their children every advantage, and want their kids to be ahead of their peers."

Does redshirting make a difference?

Painter’s work is based on a longitudinal study that looked at academic and social outcomes of delayed kindergarten entry. He followed children starting at age four or five through age 25 or 26. Incredibly, he found no academic or social benefit to redshirting (The one exception? Varsity football.) In fact, he found a small benefit to being younger in terms of slightly higher college attendance rates. But is Painter’s data, which is necessarily old (his subjects are now all in their thirties), on target? "There’s other research out there from here and abroad that finds older kids do slightly better than younger kids while they’re in school," Painter says. "We need to keep a close eye on it."

Overall, research on has found mostly unfavorable results for being older than your grade-level peers, including academic achievement that disappears in later grades and an increase in social and behavioral problems in adolescence, when being older (or different in any way) can create problems. But much of this data is old, and, in many cases, linked to studies on grade retention, which is likely more of a social stigma for a child than starting kindergarten later.

Mixed results

A recent Canadian study suggests that redshirting can have positive academic outcomes, including a reduced chance the child will repeat the third grade and improved math and reading scores in tenth grade. According to this study by the NBER, the effects are highest for boys (who are more often redshirted) and low-income students. Additionally, the researchers’ estimates suggest that not only is delayed kindergarten better, but starting too early may have negative consequences for kids.

Given these mixed findings, redshirting clearly needs more study, especially since the average age of kindergartners is on the rise. In the past 35 years, scores of states have raised their kindergarten cut-off dates. In 1975, only nine states required that kids be five when they start kindergarten. By 2010, 37 states had that requirement, with more states following suit (California will be there by fall 2014).

Next page: Redshirting kindergarten— Ready or not