It really depends how things work over there. Castes are associated with jobs and I have seen some articles that some 'teacher' cast has higher intelligence, just like eg ashkenazi jews. It could be that being pretty unsuccesful at your caste-assigned job would have left you unemployed and thus not being able to support a family, thus not being able to marry. thats obviously speculation, of course.
It does not make any sense, no matter how you look at it.
Sure, you can see those "articles", but don't forget that those are going to be based on IQ tests, and those are correlated with intelligence and... wait for it... education.
If I was of the superior caste that's what I would try to make people believe: "we are superior, and we are here because we are smarter than you. Best of luck in your next life".
Someone with a high iq will be more capable of following a certain education path. So education and iq being correlated usually means the iq measure is working as intended. If however going to a great school improves your iq that proves the specific iq measure used is flawed (as its supposed to measure innate intelligence, not education). As for the other part, I agree my line of reasoning is rather unsympathetic.
