WHY are Indian children so short?

The average baby born in India is more likely to be stunted than the average baby in sub-Saharan Africa — even though the baby’s mother is more likely to survive the birth, and he or she will probably go on to live longer and be richer and more educated.

Many explanations have been offered up for this “South Asian enigma.” . . .

We found that the South Asian enigma begins only with the second-born child, and becomes more pronounced for each subsequent baby. Among children born third or later, 48 percent are stunted in India versus 40 percent in Africa, while the rates for firstborn children are 35 percent in India versus 37 percent in Africa.

Children from the same family are most likely subject to the same external factors, like exposure to pathogens from open defecation, so there must be something else going on. We believe that the explanation is India’s deeply entrenched preference for firstborn sons.