Relative Age Effect (RAE)

Relative Age Effect (RAE) is the tendency for the youngest children in a school grade to be identified with ADHD more often than their older classmates. Because school entry is based on a cutoff date, children born just before the cutoff may be nearly a year younger — and developmentally less mature — than classmates born just after it. Their comparatively lower attention, self-regulation, or activity level may be mistaken for ADHD, increasing the likelihood of referral or diagnosis. RAE doesn’t ADHD is overdiagnosed overall or that diagnosed children don’t have ADHD. Rather, it highlights the importance of considering a child’s developmental maturity, classroom expectations, and age relative to peers during assessment.