Selected ongoing projects
Sociogenomics
Ghirardi, G. & Bernardi, F. Re-theorizing GxE research on education by degree of outcome selectivity? Here the pre-print
Abstract
This study investigates the extent to which the genetic propensity for education matters for the final educational attainment of high- or low-SES students. Previous research addressing this question has been guided by the Scarr-Rowe hypothesis which predicts that genetic influences are maximized in high-SES families. However, the empirical evidence is mixed. We propose a model that integrates compensatory and boosting advantage models from social stratification research in sociogenomics highlighting the role of educational outcome selectivity. Our model predicts that in the case of educational outcomes characterized by a low level of selectivity, such as high-school completion, genes matter more for low-SES individuals, while for outcomes characterized by a high level of selectivity, such as graduate school completion, genes matter more for high-SES individuals. We test our model, replicating the same analyses on three different datasets with genotype information, the National Longitudinal Study of Adolescent to Adult Health, the Health and Retirement Study, and the Wisconsin Longitudinal Study. The results are in line with our predictions. Our theoretical model can explain previous heterogeneous findings in the literature and can be generalized to develop testable hypotheses for other cohorts in the United States and other countries.Ghirardi, G., Gil-Hernández, G., Bernardi, F., van Bergen, & E., Demange, P., The interaction between family’s SES and genetic propensity for cognitive and non-cognitive skills on educational outcomes. Here the pre-registration - Here the pre-print
Abstract
Genes (G) and environments (E) predict education, but findings on G×E interactions are mixed. The Scarr-Rowe hypothesis claims that enriched environments allow individuals’ genetic potential to unfold, while the compensatory hypothesis expects that negative traits for educational attainment—low genetic propensity—are hardly detrimental for advantaged children. We test these competing hypotheses using pre-registered research designs and the Netherlands Twin Register genotyped panel. We contribute by (1) untangling education via polygenic indexes (PGI) for cognitive and noncognitive skills; (2) investigating childhood-to-adulthood educational outcomes; and (3) triangulating from between (trio design)- and within-family models to enhance causal inference. We report two findings. First, for secondary-school grades, standardised national test scores, and adult attainment, G×E interactions are nonsignificant over designs. Second, across designs, cognitive skills PGI are less predictive of tracking for high-SES n than low-SES children, which supports a robust negative G×E interaction. Findings suggest compensation for cognitive skills’ PGI might take place for critical educational outcomes. We discuss implications for social stratification and sociogenomics research surrounding debates on equal opportunity and compensatory school policy.Bernardi, F., & Ghirardi, G., Socioeconomic status, genes, and the differential effects of parental separation on educational attainment. Here the pre-print
Abstract
Previous studies have established a negative impact of parental separation on children’s educational attainment, which is stronger among children from high socio-economic status (SES) backgrounds. This study aims to understand why parental separation appears to have a stronger negative impact on high-SES children. Specifically, we investigate whether the observed larger parental separation penalty for educational attainment for high-SES children is concentrated among those with a low genetic propensity for education. This phenomenon could be attributed to parental separation preventing high-SES parents' ability to compensate for their children's low genetic propensity for education. We conduct the same analysis on two datasets, the National Longitudinal Study of Adolescent to Adult Health, and the Health and Retirement Study, both of which contain genetic and socio-demographic information. Our findings reveal that high-SES children with low genetic propensity for educational attainment are less likely to complete college in comparison with their peers with higher genetic propensity. Overall, our results suggest that the evidence of a stronger separation penalty for advantaged children is due to missing compensation among them.Ghirardi, G., Wolfram, T., Ruks, M., & Tropf, F., Genetic propensity for externalizing behaviours, family socioeconomic status, and adverse high-school outcomes
Abstract
This study investigates whether children's genetic propensity for externalizing behaviours influences their likelihood of experiencing adverse outcomes in high school and whether this relationship varies by family socioeconomic status (SES). According to behavioral genetics and social stratification theories, such as the diathesis-stress and compensatory advantage models, we test whether there is a stronger genetic association to adverse outcomes among low-SES children. Drawing on data from the National Longitudinal Study of Adolescent to Adult Health (Add Health) from the US and the British National Child Development Study (NCDS), we construct a polygenic index (PGI) for externalizing behaviours. Our analysis examines the impact of this PGI on adverse high-school outcomes, including failure, suspension, expulsion, absence, and misbehaviors, and explores its interaction with family SES. The findings reveal two key insights. First, a higher genetic propensity for externalizing behaviours increases the likelihood of experiencing adverse high-school outcomes. Second, the genetic propensity for externalizing behaviours is more predictive of adverse high-school outcomes among low-SES children compared to high-SES children. These results are robust to different model specifications, except for high-school suspension and expulsion. Our results suggest that high-SES families compensate for their children's high genetic propensity for externalizing behaviours, whereas low-SES families trigger these genetic propensities in their children.Breinholt, A., & Ghirardi, G., The interaction between socioeconomic status and genetic propensity for education: A systematic review and meta-analysis of molecular studies
Abstract
A growing body of research investigates whether genetic influences on educational outcomes can be suppressed or boosted by the environment in which an individual lives. Indeed, several studies have examined the interaction between the genetic propensity for education and the socioeconomic status (SES) of the family of origin, the neighborhood, or school - so-called GxSES studies. However, results are mixed. Some studies find stronger associations between genetic propensities and educational outcomes in high-SES environments, while other studies find stronger associations in low-SES environments. In this work, we conduct a systematic review and meta-analysis of studies that investigated the interaction between genetic propensity for education and SES on measures of educational attainment and achievement. We focus on studies relying on molecular genetic information in the form of polygenic indices (PGI). This study aims to answer the following questions: (1) Does the genetic propensity for education matter more for educational outcomes in high or low-SES environments? (2) Which factors may explain the inconsistent findings of the previous literature? To address these questions, we collect results from both published and working papers investigating the interaction of interest and using molecular data.Early childhood and care
Ghirardi, G., & Gioachin, F. The role of different childcare arrangements on social inequalities in children’s early cognitive competencies: A research note. Here the pre-print
Abstract
This research note investigates how childcare arrangements under age three affect early social inequalities in children’s competencies, relying on a novel decomposition approach (Yu and Elwert 2023). This approach allows us to provide a comprehensive evaluation of different childcare arrangements within a potential outcome framework, revealing not only the overall relevance of each childcare arrangement but also the importance of specific channels impacting social disparities such as prevalence (unequal exposure), effect (heterogeneous effect), and selection (within-group propensity to treatment). Using the newborn cohort of the German National Educational Panel Study (NEPS - SC1), we assess the impact of early childhood education and care (ECEC), family day-care, grandparental care, and exclusive parental care on children’s competencies in mathematics and vocabulary at ages 4 and 5. Findings highlight ECEC as the most effective approach in reducing social disparities, positively influencing children from lower socio-economic backgrounds. Conversely, exclusive parental care and family day-care increase social disparities, benefiting children from higher socio-economic backgrounds while negatively affecting those from lower backgrounds. This comprehensive evaluation identifies channels impacting social inequalities, contributing to understanding the nuanced role of childcare arrangements in shaping early social inequalities in children’s competencies.Berger, L., Ghirardi, G., Panico L., & Solaz, A., The impact of early formal childcare attendance and exposure on children’s developmental outcomes in France
Abstract
The importance of early childhood education and care (ECEC) for fostering children’s development and reducing early inequalities is widely recognized by previous studies. However, much of this evidence refers to pre-school (i.e., to 3-to 5-year-olds), and mainly stems from randomized evaluations of small-scale intensive programs based in the United States and other English-speaking countries. This study thus examines the impact of ECEC under the age of 3 on children’s development and its role in tackling the early social inequality in such outcomes in France. We ask whether attending ECEC at age 2 has a positive (or negative) impact on children’s developmental outcomes and if the role of ECEC on child development is different according to the family’s socio-economic status (SES). We address these questions, using the Étude Longitudinale Français depuis l’Enfance (Elfe), and ordinary least squares (OLS) models with inverse probability weight (IPW) to account for confounding bias possibly arising from selection into care arrangements. Our findings show that ECEC attendance positively affects children’s development and that disadvantaged children benefit more in children’s global development from attending ECEC. These results suggest that ECEC institutions may be an effective tool to reduce social inequalities in some, but not all, early child developmental outcomes.