Ahmad R. Hariri, recipient of the Award for Distinguished Scientific Early Career Contributions to Psychology, is cited for pioneering contributions to understanding the neurobiological mechanisms driving individual differences in complex behavior traits. Hariri has integrated molecular genetics, neuropharmacology, neuroimaging, and psychology in the search for specific biological pathways through which individual differences in information processing emerge and help to shape behavior. His early demonstration that common genetic variation may impact behavior and related risk for neuropsychiatric disease by biasing the functional dynamics of behaviorally relevant brain circuitry represents a landmark in the biological study of individual differences. In addition to the citation, a biography and selected bibliography of Hariri's works are provided.