The Timing of First Sexual Intercourse, Heritability, and Social/Demographic/Contextual Influences

Guang Guo, University of North Carolina at Chapel Hill
Lin Wang, University of North Carolina at Chapel Hill

Our proposed project has two objectives. First, using the twin adolescent samples collected by the National Longitudinal Study of Adolescent Health, we will examine whether or not genetic factors play an important role in influencing the timing of the first sexual intercourse among adolescents in the United States. Second, if we do find important genetic factors, we will proceed to examine how much the social, demographic, and contextual influences moderate the influences of genetic factors on the outcome. Previous work has found the effects of a number of social economic factors on first sexual intercourse such as gender, ethnicity, family structure, and neighborhood characteristics. These social and contextual influences will be examined carefully for their potential moderating influences on the expression of genetic factors. The analytical approach we will use is the random effects proportional hazards model with the gamma frailty.