The findings suggest that in a given grade, students born at the end of the calendar year may be at a distinct disadvantage. Those perceived as having academic or behavioral problems may in fact be lagging simply as a result of being forced to compete with classmates almost a full year older than them. For a child as young as 5, a span of one year can account for 20 percent of the child's age, potentially making him or her appear significantly less mature than older classmates.
The new study found that the lower the grade, the greater the disparity. For children in the fourth grade, the researchers found that those in the youngest third of their class had an 80 to 90 percent increased risk of scoring in the lowest decile on standardized tests. They were also 50 percent more likely than the oldest third of their classmates to be prescribed stimulants for A.D.H.D. The differences diminished somewhat over time, the researchers found, but continued at least through the seventh grade.
The new study, published in the journal Pediatrics, used data from Iceland, where health and academic measures are tracked nationally and stimulant prescription rates are high and on par with rates in the United States. Previous studies carried out there and in other countries have shown similar patterns, even among college students.
Image: Girl with prescription drugs, via Shutterstock