A large literature has documented strong positive correlations among siblings in health, including body mass index (BMI) and obesity. This paper tests whether that is explained by a specific type of peer effect in obesity: genetic nurture. Specifically, we test whether an individual's weight is affected by the genes of their sibling, controlling for the individual's own genes. Using genetic data in Add Health, we find no credible evidence that an individual's BMI is affected by the polygenic risk score for BMI of their full sibling when controlling for the individual's own polygenic risk score for BMI. Thus, we find no evidence that the positive correlations in BMI between siblings are attributable to genetic nurture within families.
Bibliographical noteFunding Information:
For helpful feedback, we thank Sonja Kassenboehmer, Lauren Schmitz, Olga Yakusheva, Dalton Conley, Justin Trogdon, Pietro Biroli, Hans van Kippersluis, and participants at the European Workshop on Econometrics and Health Economics, the NBER Health Economics meetings, and the kickoff meeting of the NORFACE project “Gene‐ Environment Interplay in the Generation of Education and Health Inequalities” (Grant 462‐16‐100) at the Erasmus School of Economics. This research uses data from Add Health, a program project directed by Kathleen Mullan Harris and designed by J. Richard Udry, Peter S. Bearman, and Kathleen Mullan Harris at the University of North Carolina at Chapel Hill, and funded by Grant P01‐HD31921 from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, with cooperative funding from 23 other federal agencies and foundations. Special acknowledgment is for Ronald R. Rindfuss and Barbara Entwisle for their assistance in the original design. Information on how to obtain the Add Health data files is available on the Add Health website (http://www.cpc.unc.edu/addhealth). No direct support was received from Grant P01‐HD31921 for this analysis.
All Science Journal Classification (ASJC) codes
- Health Policy