Narrowing the educational achievement gap between different social groups in India remains a major challenge, despite 60 years of affirmative-action policy (Nature 472, 24–26; 2011). Using publicly available data from the country's top medical school, the All India Institute of Medical Sciences (AIIMS), we found that performance was poor among students admitted under a government scheme for socially disadvantaged groups.

All government and government-aided institutions in India allocate a fixed percentage of places on educational courses to socially and economically disadvantaged students. But in 1995–2005, out of more than 600 indigenous tribes with access to such positions, one small group from northern India accounted for 36% of students admitted to the AIIMS.

Between 1998 and 2006, socially deprived students accepted into the AIIMS scored 13.6% less in the entrance exam than students from non-disadvantaged social classes (P < 0.001). In 1989–98, such students also had double the dropout rate of non-disadvantaged students (6% versus 3%; P > 0.05). In the ten years for which data are available (1995–2005), 61.4% of students admitted to government-reserved positions had to resit examinations in at least one subject, compared with 15.2% of non-disadvantaged students (P < 0.001).

To address such inequality, India should adopt measures that have proved successful in other countries. These include wider access to quality primary education; standardized assessment of students; and academic support for students who are lagging behind. More research to assess this inequality is also needed to inform education policy.