Why was the caste system central to indian culture?

The social historical theory explains the creation of the Varnas, Jats and of the untouchables. According to this theory, the caste system began with the arrival of the Aryans in India. The Aryans arrived in India around 1500 BC. ... The Aryans disregarded the local cultures.

the earthquake in haiti was a magnitude of 7.0 according to the u.s geological survey yet the smaller earthquake in haiti killed more than 200,000 and left more than 1.2 million people homeless. the chile earthquake was a magnitude of 8.8 and 500 times more stronger but chile's earthquake only injured 712 people.