@TechReport{iza:izadps:dp12763, author={Brunello, Giorgio and Sanz-de-Galdeano, Anna and Terskaya, Anastasia}, title={Not Only in My Genes: The Effects of Peers' Genotype on Obesity}, year={2019}, month={Nov}, institution={Institute of Labor Economics (IZA)}, address={Bonn}, type={IZA Discussion Paper}, number={12763}, url={https://www.iza.org/index.php/publications/dp12763}, abstract={We use data from three waves of Add Health to study the short- and long-run effects of high school peers' genetic predisposition to high BMI – measured by grade-mates' average BMI polygenic scores – on adolescent and adult obesity in the U.S. We find that, in the short-run, a one standard deviation increase in peers' average BMI polygenic scores raises the probability of obesity for females by 2.8 percentage points, about half the size of the effect induced by a one standard deviation increase in one's own polygenic score. No significant effect is found for males. In the long-run, however, the social-genetic effect fades away, while the effect of one's own genetic risk for BMI increases substantially. We suggest that mechanisms explaining the short-run effect for females include changes in nutrition habits and a distorted perception of body size.}, keywords={BMI polygenic scores;peer effect;obesity;Add Health}, }