In the 2000s I read a fair number of books such as Nicholas Dirks’ Castes of Mind. The impression one gets from these books is that jati-varna status and stratification are protean. Much of it a recent function of jockeying during the colonial and liminal colonial era. The “uplift” of groups such as Patidars and Marathas, for example. Or the emergence of Kayasthas as literate non-Brahmin service castes for Muslim rulers.
The genetic data that emerged in the 2000s though shocked me with two facts:
– There is within region a rough correlation, imperfect, but existent, of what we now call “steppe ancestry” and caste status
– Jati groups in a given region were shockingly distinct, and many exhibited a lot of genetic drift.
Endogamy was deep, ancient, powerful, and, genetic differences of the deep past persisted, rather than mixing away.
These are not perfect generalizations. The correlation between steppe and and status breaks down in the northwest to a great extent (thought still not totally). There are groups, such as Bengali Kayasthas, who approximate Brahmin status (even still being lower), but are genetically similar to non-elite non-Brahmins. Within the data there are castes which seem composites (Khamboj in some recent data).
This is a preface to the fact that I’ve gotten into recent arguments inadvertently online about caste, and its role in the Indian future. So I decided to look at the data. Here is my short conclusion: jati-varana is way more robust than I would have thought. Outmarriage rates were 5% as of 2011, and they didn’t vary that much by social status. At current rates it could take 500 years for caste not to be a big deal in India.