Joel T NiggJoel Nigg, PhD, is a licensed clinical psychologist and research scientist who has been studying children's developmental struggles for over 25 years. The major focus of his work has been ADHD and associated learning and behavioral challenges and ther relation to development of temperament, emotion, and cognitive styles as well as genetic and environmental influences. He is a Professor of Psychiatry and Behavioral Neuroscience at Oregon Health & Science University and lives in Portland, Oregon. Read More Read Less