There are different theories about the establishment of the caste system. There are religious-mystical theories. There are biological theories. And there are socio-historical theories.

The religious theories explain how the four Varnas were founded, but they do not explain how the Jats in each Varna or the untouchables were founded. According the Rig Veda, the ancient Hindu book, the primal man - Purush - destroyed himself to create a human society. The different Varnas were created from different parts of his body. The Brahmans were created from his head; the Kshatrias from his hands; the Vaishias from his thighs and the Sudras from his feet. The Varna hierarchy is determined by the descending order of the different organs from which the Varnas were created. Other religious theory claims that the Varnas were created from the body organs of Brahma, who is the creator of the world.

The biological theory claims that all existing things, animated and inanimated, inherent three qualities in different apportionment. Sattva qualities include wisdom, intelligence, honesty, goodness and other positive qualities. Rajas include qualities like passion, pride, valour and other passionate qualities. Tamas qualities include dullness, stupidity, lack of creativity and other negative qualities. People with different doses of these inherent qualities adopted different types of occupation.

According to this theory the Brahmans inherent Sattva qualities. Kshatrias and Vaisias inherent Rajas qualities. And the Sudras inherent Tamas