Eldest son preference and preferences

Why Are Indian Children Shorter Than African Children? by Seema Jayachandran and Rohini Pande.

It is wonderful that there are people investigating phenomenon you don't even know exist. Always with the five questions of the discussion pyramid, but holding that in abeyance, here is the abstract.

Height-for-age among children is lower in India than in Sub-Saharan Africa. This presents a puzzle since India is richer than the average African country and fares better on most other development indicators including infant mortality. Using data from African and Indian Demographic and Health Surveys, we document three facts. First, among firstborns, Indians are actually taller than Africans; the Indian height disadvantage appears with the second child and increases with birth order. Second, investments in successive pregnancies and higher birth order children decline faster
in India than Africa. Third, the India-Africa birth order gradient in child height appears to vary with sibling gender. These three facts suggest that parental preferences regarding higher birth order children, driven in part by cultural norms of eldest son preference, underlie much of India's child stunting.

I didn't know this phenomenon existed. The three facts are unexpected (to me). More data and replication might provide different answers but my take away is that our understanding of the breadth and importance of culture on outcomes is woefully inadequate.