Gene-environment correlations (rGE) exist when genes vary across discrete physical, social, or behavioral environments. A failure to account for these correlations can lead to confounding in gene-by-environment studies. The proposed project aims to investigate rGE through the use of structural differences in environments in the Health and Retirement Study. For example, one’s birth cohort should be largely independent of genotype. Alternatively, parental education should have a strong rGE component. This project aims to first quantify rGE over a range of such environments. The second phase of the project is to analyze the effect of rGE on heritability-by-environment studies by leveraging both structural differences between environments as well as outcomes. For example, height should be relatively independent of non-genetic influences, especially as compared to a variable like SES. This research will advance biodemography inquiry as it will inform thinking on the identification of rGE and its effects on gene-by-environment research.