The Incas believed in predestination and fate of caste. They did not have problems of professional orientation: the occupation of each person was known since his birth. The son of a peasant farmer is required to become the son of a warrior - a warrior. Leaving no chance for error in the future, the basis of caste is applied directly to the body of the baby. The head of a newborn with another soft fontanel is a special wooden vise, change the shape of the skull. So Incas sought to human head had a shape corresponding to its future activities: skull king, for example, was supposed to be square. The operation was painless, similar to wearing a device for occlusion. Soft Skull in wooden helmet changed its shape. Thus, even without clothes and abandoned retinue of the king's sons they were kings, all of them recognized, as only they could put on the crown, which had a square shape. Skulls warriors gave a triangular shape. The peasants head was pointed.
So the Inca society was unshakable. No social change. Personal ambitions pose no threat to the existing order, as each form of his skull was once and forever tied to his social status and profession.