Parents often wonder, “Is this normal for my child’s age?” The truth is, behavior follows brain development. A 3-year-old’s 2-minute attention span and daily meltdowns are just as normal as a teen’s push for independence. This guide breaks down what’s typical at each stage—attention spans, emotions, social skills—along with green flags, red flags, and real-life parenting scripts. When you understand your child’s brain build-out, you can set realistic expectations, respond with confidence, and guide them toward resilience at every age.