Early life determinants of social disparities among young adults: A longitudinal study in vulnerable communities in South Africa

South Africa has achieved major poverty reductions in the post-Apartheid era, but substantial variations in progress between population groups have been documented, and inequalities between poor Black communities and other parts of South Africa persist. Similarly, life chances and inter-generational mobility vary with proximal early life economic environments. The long-term interrelationships of different aspects of these environments are not well understood. Using prospective data from the Birth to Thirty (Bt30) cohort, we assess the relative importance of early life family and neighborhood socioeconomic status (SES) for later life educational attainment and criminality among Black children from low-income communities in Soweto-Johannesburg, South Africa. We follow a multi-step nonparametric adjusted regression approach to reduce assumptions about the nature of the relationships between outcomes and exposure variables, and we express interactions as nonlinear marginal effects. Our study finds that both childhood home SES and neighborhood SES are predictive of more favorable outcomes later in life. Home SES appears generally more predictive of young adulthood outcomes than neighborhood SES, particularly for educational outcomes. Girls fare substantially better both in terms of educational attainment and in terms of lower criminal engagement. These pro-female gaps appear to be particularly large in higher SES homes for educational attainment. Our findings highlight the critical importance of children's home environments in general, and particularly for children's educational attainment. Further support for programs to reduce socioeconomic inequalities in the current adult population can likely contribute substantially to reducing inequalities in future generations.