Joseph P. Hegmann, Linda K. Dixon, Thomas W. Klein, Allan R. Kuse, Benjamin Padeh, Frances I. Lewitter, Hsiu-Zu Ho, Laura A. Baker, George P. Vogler, Treva K. Rice, Michele C. LaBuda, Jacquelyn Gillis Light, Sally J. Wadsworth, Maricela Alarcon, Valerie S. Knopik, Chayna J. Davis, Jesse L. Hawke,
His contributions include major twin and adoption studies of cognitive abilities, genetics of learning disabilities, and, when molecular tools became available, pioneering the use of DNA markers to locate genes that influence behavioral characters.
He established the world's first large twin study of dyslexia at the Institute for Behavior Genetics in Boulder, and supervised over 17 PhD students.
Among his works are a standard text on behavior genetics and original work on behavior-genetic methodology, some of it in collaboration with David Fulker.
DeFries' articles have been cited over 8000 times and he has an h-index of 48.
^Wadsworth SJ, DeFries JC, Olson RK, Willcutt EG (2007) Colorado longitudinal twin study of reading disability. Annals of Dyslexia, 57(2), 139-60.
^Alarcon, M., Plomin, R., Fulker, D.W., Corley, R. & DeFries, J.C. (1998). Multivariate path analysis of specific cognitive abilities: data at 12 years of age in the Colorado Adoption Project. Behavior Genetics28:255-264.