Today, it is widely accepted that most traits are both genetically heritable and affected by the environment. In the social sciences, the previous nature-nurture debate has been replaced by a new paradigm analyzing the interplay between genetics and the social environment (e.g., in sociology: Breinholt and Conley 2023; in economics: Houmark, Ronda, and Rosholm 2024; in psychology: Wertz et al. 2020). Rooted in sociology, this project analyzes how social mechanisms of genetic effects play out in three realms affecting childhood educational performance: family, daycare, and school peers, and asks how knowledge on these social mechanisms of genetic effects changes theories of justice on social stratification. The project thereby advances knowledge on the complex interplay between the social environment and genetics and addresses ethical questions re-actualized by the integration of molecular genetics in the social sciences. Addressing these issues will promote well-being of children.