Here is an abstract from a paper by Jayachandran and Pande titled “Why Are Indian Children So Short?”:
India's child stunting rate is among the highest in the world, exceeding that of many poorer African countries. In this paper, we analyze data for over 174,000 Indian and Sub-Saharan African children to show that Indian firstborns are taller than African firstborns; the Indian height disadvantage emerges with the second child and then increases with birth order. This pattern persists when we compare height between siblings, and also holds for health inputs such as vaccinations. Three patterns in the data indicate that India's culture of eldest son preference plays a key role in explaining the steeper birth order gradient among Indian children and, consequently, the overall height deficit. First, the Indian firstborn height advantage only exists for sons. Second, an Indian son with an older sibling is taller than his African counterpart if and only if he is the eldest son. Third, the India-Africa height deficit is largest for daughters with no older brothers, which reflects that fact that their families are those most likely to exceed their desired fertility in order to have a son.