in G–E relationships across racial/ethnic groups, because the frequency of alleles at specific markers, the associations between alleles, and the distribution of exposure to specific environmental conditions can be different by population group. Regardless, it is important to recognize and address the relevant ethical and cultural issues that will emerge in this effort to be more inclusive and to provide equal access to this area of research (a topic covered by other articles in this special issue). Second, methodological advancements will strengthen our confidence in study findings, including larger sample sizes, greater consistency in phenotypic measures to facilitate meta-analysis, and careful selection of genetic effects and rigorous testing of G–E relationships5,50–52. Third, we focused on selection of environmental factors that have both theoretical and empirical precedent for inclusion in the study of G–E relationships. This revealed a relative dearth of studies that examined higher-order social control and trigger mechanisms, e.g., at the community- and societal-levels, which have broadly been shown to influence racial/ethnic differences in a variety of health outcomes. New investigations need to consider the challenge of how to more accurately capture and reflect the role of the environment in using a multi-level and longitudinal framework, as suggested by
