John Hewitt

Professor John Hewitt of the Institute for Behavioral Genetics at the University of Colorado Boulder is a leading figure in behavioral genetics. He has served as Editor-in-Chief of Behavior Genetics for 23 years and directed the Institute from 2001-2022.

• Key research areas: behavioral genetics of substance use, developmental psychology, genetic epidemiology, and neurogenetics
• Active grants include NIDA R01 DA054087 and T32 MH016880

His work combines twin studies, longitudinal designs, and genomic methods to investigate genetic/environmental influences on behavior. Recent publications focus on cannabis legalization effects, brain development genetics, and behavioral risk factors.

• 15+ recent articles address cannabis use, mental health, cognitive traits, and policy impacts
• Methodologies: genome-wide association studies (GWAS), co-twin controls, and behavioral economic models

He has mentored numerous researchers including Brett Haberstick, Chandra Reynolds, and Naomi Friedman, while collaborating on interdisciplinary projects across psychology, molecular biology, and statistical genetics.