Didn't the Ameican Indians show the colonialists how to harvest the land? In many third world countries today, the tribal people don't know how to sustain their people during draughts, etc. But the Indian knew how to treat Mother Earth, and it rewarded them. So I think the race certainly had the potential for intelligent progression just as much as the Anglos did, and have.
I'm not sure about that, MM. If I remember my history correctly they introduced the settlers to Maize (corn), but, I'm certain farming was not unknown to the settlers.
Native Americans have plenty of "potential for intelligent progression", but they did not have the technological advancements that were made in Europe. Mostly, because they had different beliefs than Europeans did and they were happy to live with nature.
Too bad we didn't learn that from them!
It wasn't "intelligence" that kept them from advancing like Europe did, it was contentment with their lives here in "The New World".
Of course, that is all my opinion so take it for what it is worth.
Immie