Why do we know more about the Mayan, Aztec, and Incans?

The Mayas, for example, made striking advances in writing, astronomy, and architecture. Both the Mayas and the Aztecs created highly accurate calendars. The Aztecs adapted earlier pyramid designs to build massive stone temples. The Incas showed great skill in engineering and in managing their huge empire.

Explanation:

they became hereditary because there weren't many jobs for people in lower classes

set times for each and always know when there coming