Why do ADHD traits cluster in certain families?

ADHD has a strong genetic component, so it often runs in families. Traits like impulsivity, attention differences, and emotional reactivity can appear across generations, sometimes in different forms. Environmental factors also play a role. Family routines, stress patterns, and coping styles can reinforce how symptoms show up. It is also common for parents to recognize ADHD traits in themselves only after a child is diagnosed. This clustering does not mean something went wrong. It reflects shared neurobiology interacting with shared environments over time.