College of LAS « Illinois


The Kindergarten Waiting Game

Delaying a child’s enrollment in kindergarten may be less beneficial—and more harmful—than you think.


For the past 30 years increasing numbers of children have enrolled in kindergarten at age six instead of the traditional age of five. Research at the U of I indicates that delaying a child for a year, however, only temporarily elevates their scholastic achievement and indirectly increases grade repetition and diagnoses of Attention Deficit/Hyperactivity Disorder (ADHD).

While it’s true that older children generally are higher achievers in early grades, research by U of I’s Darren Lubotsky, a professor of economics and labor and industrial relations, and Todd Elder at Michigan State University believe it’s the result of having more knowledge prior to entering school rather than being better able to learn the material.

As early as the third grade, the researchers found, the association between entrance age and test scores is gone. This is particularly true amongst low-income students who generally enter school with fewer academic skills than more affluent students.

Even amongst more affluent students, however, the association between entrance age and test scores is typically gone by eighth grade, the researchers report.

The researchers also estimate that when schools move kindergarten cutoff birth dates from December 1 to September 1—thus raising the average age of kindergarten students by holding back children who turn five in the fall—it increases the number of ADD/ADHD diagnoses by 25 percent amongst children whose own entrance age was unaffected by the date change.

This could be because teachers play a critical role in diagnosing ADD/ADHD (symptoms must be displayed in two separate places before an official diagnosis), not to mention whether a child repeats a grade, and the teachers are comparing children who are younger relative to their classmates, the researchers write.

“Some diagnoses [of ADD/ADHD] may simply reflect a lack of emotional maturity among young kindergarten entrants,” the researchers write. “Alternatively, the oldest children in a class may be under-diagnosed because their disabilities are masked in comparison to the behavior of younger classmates.”

Winter 2011