The Confounding (or Lack Thereof) of Behavioral and Genetic Components of Health Outcomes

Benjamin Domingue, University of Colorado at Boulder
Brian Houle, University of Colorado at Boulder
Jason D. Boardman, University of Colorado at Boulder

Most health outcomes of interest to social demographers including smoking, alcohol consumption, and obesity are strongly affected by both behavioral and genetic components. The relationship between health outcomes such as obesity or smoking and the behavior of an individual, such as their educational achievement, are well-known. Many important health outcomes also exhibit strong genetic components with heritabilities exceeding 40%. In this study, we investigate the potential for confounding between these two components in predicting health outcomes. In particular, we utilize models that include a random genetic effect that is structured by the relatedness (based upon measured genotype) of individuals in the sample. We demonstrate that the coefficient of the behavioral component is relatively unaffected by the introduction of the genetic component across a variety of health outcomes. In general, the genetic component is robust to the inclusion of the behavioral outcome although some exceptions are noted.