Enrollment of both fraternal and identical infant twins in Colorado began in 1985 and continued for a period of 7 years. The purpose of this research is to study the varying genetic and environmental influences on development, including cognition, temperament, physical development, intelligence and emotion.
1. Friedman, N.P., Miyake, A., Corley, R.P., Young, S.E., DeFries, J.C., & Hewitt, J.K. (2006). Not all executive functions are related to intelligence. Psychological Science, 17, 172-179. | pubmed abstract |
2. Young S.E., Rhee S.H., Stallings M.C., Corley R.P. & Hewitt J.K. (2006) Genetic and environmental vulnerabilities underlying adolescent substance use and problem use: general or specific? Behav Genet, 36(4), 603-15 | pubmed abstract |
3.Button, T.M.M., Rhee, S.H., Hewitt, J.K., Young, S.E., Corley, R.P., Stallings, M.C. (2007) The role of conduct disorder in explaining the comorbidity between alcohol and illicit drug dependence in adolescence. Drug and Alcohol Dependence, 87, 46-53. | pubmed abstract |