How long Indians live on average depends on the hierarchy of the social groups they belong to with upper castes living about four to six years more than women and men from the scheduled castes and scheduled tribes. This holds across regions, income levels and time. While life expectancy across all social groups has improved significantly, the gap between them persists and in some cases even worsened between 1997-2000 and 2013-16.
The gap in life expectancy between upper castes and scheduled caste men, for instance, increased from 4.6 years to 6.1 years. The gap between upper caste men and Muslim men worsened more sharply, going from just 0.3 years to 2.6 years and that between upper caste and Muslim women from 2.1 to 2.8 years in this period. This was revealed in a study analysing detailed data from the second and fourth round of the National Family Health Survey (NFHS). The study was published in the journal Population and Development Review.

In general, the gaps in life expectancy between lower caste groups and upper castes have reduced marginally among women. But among men, it has worsened for scheduled castes, Muslims and OBC men compared to upper castes. While the gap reduced for scheduled tribe men from 8.4 years, it remains wide at seven years.
The study also showed that the gaps persist whether we look at life expectancy at birth or at later stages in life. Another study by one of the researchers with some others showed that they also hold when we look at members of social groups within the same wealth levels. What this means is that the gaps are not solely due to higher infant and child mortality among disadvantaged groups and nor can they be put down simply to economic factors.
Contrary to the belief that life expectancy is driven by child mortality, the study showed that significant differences in mortality persists between social groups at age 15 and even 60. It also showed that the contribution of mortality differences in adult ages increased between 1997–2000 and 2013–2016. By 2013– 2016, 1.7 years of life expectancy deficits for SC women and 2.5 years for SC men came from ages 60+, compared to just 1.5 for women and 1.2 years for men from the 0-5 age group.
“This pattern is similar for differences between STs and high castes. These trends reveal a decline in the importance of disparities at the younger ages and the growing importance of disparities at older, adult ages,” observed the authors of the study adding that it underscored the need to examine differences beyond the childhood ages.
The Hindi belt including Rajasthan, Uttar Pradesh, Uttarakhand, Bihar, Jharkhand, Madhya Pradesh and Chhattisgarh — which accounts for about 44% of India’s population — has the lowest life expectancy for all social groups. The differences in life expectancy between social groups holds here and across almost all regions. The Northeast is the only region where scheduled tribes, who have a higher social status in the region, have higher life expectancy than upper castes.
In the hierarchy of social groups, Muslims fitted in just below the upper castes in life expectancy in 1997-00. However, by 2013-16, the gap had widened significantly. The 1997-00 pattern is what is known in academic circles as the “Muslim mortality paradox” — a socially disadvantaged group having lower infant mortality levels than even upper castes — attributed to, among other things, better sanitation due to a lower prevalence of open defecation. The paper says further study is needed to understand why this has changed.
“Social differences in longevity in India are exceptionally large in the context of global health disparities. The salience of the mortality disparities we document is heightened when considering that the combined population size of any two of these three marginalised social groups is as large as the population of the US,” noted the authors.