Do kids with ADHD seem “immature” for their age sometimes?

Yes, this is a well recognized part of ADHD. Emotional regulation and executive functioning often develop more slowly, which can make a child seem younger emotionally than their peers. This doesn’t reflect intelligence or potential. It means their emotional skills lag behind their chronological age. Clinicians often encourage parents to think in terms of emotional age rather than calendar age. Supporting development rather than expecting age typical behavior can reduce frustration and improve outcomes.