This project examines the roles of biological and environmental predictors of educational and socioeconomic achievement in young adults. Using the Add Health longitudinal survey the study examines outcomes among sibling pairs, classified according to degree of biological relatedness. The study adjudicates between competing claims regarding the role of biology vs. social ascription in shaping in intergenerational mobility. To that end, it is grounded in bio-medical as well as status attainment literatures from different disciplines. Structural equations models (SEMs) are applied to estimate the extent to which variation in an outcome measure depends on the shared biological vs. environmental influences experienced by siblings raised in the same family, or on specific environmental influences unique to the individual sibling. Analyses also estimate the impact of interactions among siblings (e.g., emulation or competition) and the effects of assortative mating among parents.
Broader Impacts This project integrates a biomedical approach with traditional social-scientific approaches to social stratification and intergenerational mobility. The project intends to generate findings of interest to an interdisciplinary set of researchers and the general public. In addition, findings may shape policy reforms aimed at optimizing outcomes related to educational attainment and socio-economic mobility.
This project examines the roles of biological and environmental predictors of educational and socioeconomic achievement in young adults. Using the Add Health longitudinal survey the study examines status-related outcomes among sibling pairs, classified according to degree of biological relatedness. The study adjudicates between competing claims regarding the role of biology vs. social ascription in shaping intergenerational mobility. To that end, it is grounded in bio-medical as well as status attainment literatures from different disciplines. Structural equations models (SEMs) and DeFriese-Fulker analysis are applied to estimate the extent to which variation in an outcome measure depends on the shared biological vs. environmental influences shared by siblings raised in the same family, or on specific environmental influences unique to the individual sibling. Analyses also estimate the impact of interactions among siblings (e.g., emulation or competition) and the effects of assortative mating among parents. The shared environment plays a substantial role in some life course outcomes, such as verbal ability (PPVT test score), college plans, educational attainment, and achieving at least some college education. However for all outcomes (except home ownership) genes play a more important role than the shared family environment, and the aetiology of some outcomes (such as college graduation, occupational wages, personal earnings, and subjective social status) is predominantly genetic. For educational attainment in particular the substantial role of the shared environment, especially for twins, is not accounted for by the strong degree of assortative mating in the data nor by direct effects of educational attainment of the siblings on each other. Influences of both the genes and the shared environment decline with the position of an outcome later in the life course, resulting in an overall trend of declining influence of the family of origin with life course position. However, the shared environment represents a significantly greater share of overall family influence for outcomes related to formation of the family (household income, household assets, and home ownership), than for outcomes that are not so related. This pattern may indicate non-monotonicity in the effect of the shared environment over the life course, with a recrudescence of non-genetic influences of the family of origin during the period of family formation. Broader Impacts This project integrates a biomedical approach with traditional social-scientific approaches to social stratification and intergenerational mobility. The project is generating findings of interest to an interdisciplinary set of researchers and the general public. In addition, findings may shape policy reforms aimed at optimizing outcomes related to educational attainment and socio-economic mobility. The finding of non-negligible shared environmental influences on a number of status-related (mainly educational) outcomes suggests there is room for policy-based improvements in equalizing opportunities for these outcomes.
