The discord of caste and science

A poster at IIT-Mandi on 4 September 2026, during the Krishna Janmashtami celebrations, depicting the caste system with four ‘varnas’. | Photo credit: Special arrangement

All people must be treated equally. That is a moral and constitutional position. It is not a scientific position because science carries no moral or constitutional authority.

The normative system laid down in the “Manusmriti” expresses the “principle” that a person’s birth says something essential about who that person is to be, whereby persons born into specific social categories are assigned a place in the division of labor and a set of permitted relationships and social rights. Modern constitutional thinking is radically different. According to the Magna Carta, the English Bill of Rights and today’s constitutional democracies, individuals have rights that depend not only on their position in the social hierarchy. After all, the fundamental rights of the Indian Constitution are associated with persons and citizens, not with inherited social functions.

Yet a poster that appeared at IIT-Mandi on 4 September 2026 stated that the role of “Brahmins” is to “spread God’s message”, “Kshatriyas” to “protect society and spirituality”, “Vaishyas” to “drive the economy, support others” and “Shudras” to “serve the upper classes”.

The science underlying the technologies with which the IITs are primarily concerned offers another conception parallel to the constitutional view, rooted in a different kind of authority.

The authority of science

While some defenders of the caste system have argued that it is based on inherited biological differences, the system is actually the cause of the differences, rather than the inheritor of them. The human organism develops as its genes interact with its environment, and caste-based discrimination affects those environments. Studies on the social determinants of health have revealed caste-based inequalities in health care and access to health care, while social epigenetics has found that social circumstances can induce biological changes through mechanisms that affect the way genes are regulated.

People of black African heritage and indigenous peoples in Asia have non-identical genomes for this reason. By applying scientific methods, we know that the differences between these peoples do not justify the caste system. Instead, differences in the social circumstances of these people throughout history—including the societies they were part of at any point practicing a hereditary, hierarchical system—influenced the way they evolved.

In a landmark 2009 study, geneticists reported that most present-day Indians are descended from two distinct ancient populations that mixed extensively before endogamy took root, and that present-day Native American groups contain mixtures of these ancestors. The team also said that today there is significant genetic variation between different communities due to a long history of endogamy. Other studies of Indian populations have also reported strong founder effects (when a new population emerges from a small group of individuals and inherits a lack of genetic diversity) due to endogamy. The genome does not report that these people were ordained to marry each other, but records the fact that they chose to do so for reasons beyond scientific wisdom.

The human nervous system is also highly plastic: it is constantly rewired in response to each experience in a lifelong process. Not everyone is good at everything, but plasticity means that the neurological system co-evolves with each person’s environment, interests, temperament and individual choices, giving rise to different abilities in people.

No matter how well equipped, scientific practice has never been able to say whether all men are equal. This is a political and ethical proposition that cannot be tested or proven. But he says that all humans are members of one species, that their development is shaped by their experiences, and that the social environment can become embodied.

Just as caste limits the plasticity of the human brain, it also limits the human capacity for culture. Homo sapiens can gather knowledge and pass it on so that other H. sapiens don’t have to learn from scratch. However, discrimination based on caste limits the diffusion of knowledge and narrows the social scope within which one of the defining abilities of our species can operate—as if a student’s ability to solve a differential equation had anything to do with the ritual status of their ancestors.

This clash of possibilities is what makes the appearance of a caste-reinforcing message at the center of scientific learning particularly tragic.

mukunth.v@thehindu.co.in

Published – 8 Sep 2026 07:00 IST