India's population explosion is natural, particularly when advanced contra-receptive materials such as condoms are considered luxuary items with most people being too poor to afford them despite the huge efforts of Bill Gates Foundation in India.
The same as Sub-Sahara Africans and their genetic cousins of Australia Astraloid, Indians (Astraloid as the base race for both so-called "high" castes and "low" castes) naturally follow r-strategy which is to produce a lot of eggs, I mean WOW..., in the hope that 1 or several of them could avoid die from hunger and/or deseases in order to survive into adulthood (so dear Indian members here in PDF: consider yourselves lucky
). In the animal world, the counterparts are fish, mosquitos, flies, rats, chicken, etc that also follow r-strategy.
Whereas the Chinese ( the East Asians in general) and indigenious Europeans naturally follow the k-strategy which is reverse of r. Even the Chinese mainland had no 1-child policy, the birth rate would still be very low, comparable to other ethnic Chinese regions such as HK, Singapore, Taiwan, Chinese communities in Europe, the US etc. In the animal world, the counterparts are cats, dogs, bears, tigers, dolphins, etc that also follow k-strategy.
Survival strategy is statistically long proven to be positively correlated with IQ, you guessed it.
High IQ groups most likely follow k-strategy producing a few with concentrated care having longer life span, while low IQ groups such as Indians mostly follow r-strategy producing a lot (comparatively, of course)with little or no care having shorter life span. It's nothing new.