Early vocabulary size is genetically linked to ADHD, literacy, and cognition

Are genetic factors underlying children's language development linked to later-life outcomes? In a genome-wide analysis, an international research team found genetic associations between children's early vocabulary size and later-life ADHD, literacy, and general cognition. These associations changed dynamically across the first three years of life. Both producing more words in infancy and understanding fewer words in toddlerhood were associated with a higher risk of ADHD.