After more than 20 thousand years of differentiation and development, Indians have produced many different nationalities and languages. But among the Indians, only the Mayans invented writing, and other Indians had no writing. This is mainly because Indians have no concept of private property, and they are in the clan era of public ownership. North America lacks agricultural crops, so it is difficult to create a stable civilization and maintain a stable food supply. Therefore, they didn't invent words to record their civilization.