Christian-dominated Mizoram – 87% of the population is Christian – has the most inter-caste marriages in India, a nation where 95% of Indians marry within their caste, according to this 2016 report from the National Council of Applied Economic Research, a New Delhi-based think-tank.

Meghalaya and Sikkim followed Mizoram, with 46% and 38%, respectively, of all marriages inter-caste, according to The Indian Human Development Survey, based on nationwide surveys conducted between 2011-'12.

The three north-eastern states were followed by Muslim-dominated Jammu and Kashmir (35%) and Gujarat (13%).

These data belie the perception that with modernity and economic progress, traditional barriers of caste have broken down.

The caste system is an ancient relic of a social hierarchy once based on division of labour. People are born into their caste. They cannot change it.

The inter-caste marriage findings are from IHDS-2 (2011-'12), a data set put together by the University of Maryland and NCAER. A representative sample of 41,554 households contacted for the study was spread across 33 states and union territories, in rural and urban India.

How do people marry in the states of India?

As many as 95% women surveyed said their husbands’ caste was the same as their’s. This was the question NCAER used to determine the proportion of inter-caste marriages: “Is your husband’s family the same caste as your native family?”

In Madhya Pradesh, almost all (99%) people were married in their own caste, followed by Himachal Pradesh and Chhattisgarh, both at 98%.

Indians are legally allowed to marry outside their caste. A law on inter-caste marriage was passed more than 50 years ago, but those who do are still threatened or attacked, often by their own families.

Change is slow, but it is coming

As many as 27% of respondents said they knew people in their communities who married outside their caste. In cities, this number was 36%.

IHDS-II surveyors asked respondents: “Do you know anyone in your community who has had an inter-caste marriage?”

People are more forthcoming with perception of others than information about themselves, the researchers found.

“Think of a village pradhan (chief) whom everyone knows… there is only one pradhan in a village. Knowing someone, particularly someone who has engaged in “unusual” behavior, like inter-caste marriage, is always going to be higher than one doing it oneself,” Sonalde Desai, a demographer, senior fellow at NCAER and Professor of Sociology at University of Maryland, told IndiaSpend. “I am surprised that only one in four individuals knows someone [in an] inter-caste marriage.”

This article first appeared on Indiaspend, a data-driven and public-interest journalism non-profit.