True Left

""Subnarmadans" apparently refers to those Indians who are located geographically south of the Narmada-Tapti basin."

In other words, the less Turanized ones.

https://www.draliceevans.com/post/why-are-southern-north-eastern-indian-states-more-gender-equal

Southern and North-eastern women are more likely to

    survive infancy

    be educated

    marry later

    choose their own husbands

    interact more closely with their husbands

    bear fewer children

    own more assets

    exercise more control over their dowry

    socialise with friends

    move more freely in their communities and

    work alongside men.

In North/North-west India, women are much more constrained, and sex ratios are far higher.

Education, paid work, and age are all associated with greater economic and physical autonomy. But even if a woman completes secondary school, she is less likely to choose her husband if she lives in the North.

Region is a strong predictor of female survival, literacy, autonomy, employment, and independent mobility. A woman with the exact same household wealth/ caste/ religion will likely have more autonomy if she lives in the South.

See also:

https://trueleft.createaforum.com/mythical-world/turanian-sexism/

The evidence is especially strong because Northeast India (which as we know is also less Turanized) behaves more like South India.

Continuing:

pastoralism was historically pervasive across North-west India, and this entrenched patriarchal norms. Pastoral societies tend to be gender segregated. Men take the herd to pasture, while women stay at home, tending newborn animals and processing milk into ghee. Men may leave for a few days, searching for new pasture. If men cannot observe women's whereabouts, they may worry about paternity, and try to control female sexuality.

Analysing societies across the world, Anke Becker finds that pre-industrial societies that were more dependent on pastoralism had stronger son preference and are more likely to believe in male superiority. These effects persist today. Women whose ancestors subsisted on pastoralism report less control over their sexuality and greater preference for sons, which is reflected in uneven sex ratios. Pastoral groups are also disproportionately patrilineal and patrilocal.
...
exogamous patrilineality is pervasive across North India. As Anke Becker shows, it is strongly associated with ancestral pastoralism.

Pastoralism may have also influenced India's caste-system. Brahmins dominate business, public service, politics, the judiciary, and universities. Upper caste purity and prestige has been preserved through female seclusion, prohibiting polluting sexual access. These patriarchal norms may be rooted in ancient livelihoods. Genetic data suggests that Brahmins have some contributions from steppe pastoralists.

Which is what we have been saying all along.