--Its VERY persistent. Hindu caste system is like the S.africa apartheid system lasting 1000s of years. Interracial marriage/relationship in US  definitely have a much higher frequency than those of inter-caste parallels in hindustan

https://www.theguardian.com/world/2006/dec/28/india.mainsection

-- Caste system is an important part of the sublime hindu spirituality/religion with astounding apologetics OR hinduism is veneer imposed by 'aryan'conquerors on the vanquished. White christians had tried something similar on bible scripture but with much less success because christianity sprang from different history circumstances

--In non-hindu countries,while races could 'behave' like castes; castes don't behave like races. Both england and japan had occupation castes/clans until recent centuries but they're  gone by now. The Coopers no longer make barrels. Some chinese family names are indicative of occupation clans in antiquity long passed