1. I believe the major cultural element would be Religion.
The population in south Asia is not even close to be as diverse as American Population.
In the past, populations with different religion even involved in Civil war that could only be resolved by separating the people into two regions for each region (the Muslim went to Pakistan, the Hindu stay in India)
2. The difference between the poor and the rich in India is even wider than successful capitalistic countries.
This happen because the social stratification in Indian society is much more open and deemed as acceptable by Indian Citizens, which limit the opportunities of civilians in lowe strata
3. The factors that caused the difference are:
- Opportunities that exist within each social stratification
- The after effect of colonization period which allocate the resources in india to the families or organizations that supported the British Empire
- Traditional view that often prevents the advancement in science