I firmly believe that one day we will find out the ancient world has a much bigger and overarching story than is currently known. And it will blow your mind. The Korean-Tamil hypothesis comes to mind.
They are every bit as smart (some might say, “smarter”); they just don’t have the social, physical, and logical infrastructure, or access to resources, that more developed societies have.
I think that was the premise of Guns, Germs and Steel.
Individualism and collectivism are tightly woven together. Both are needed, its a mistake to think that you can have one without the other.
And actually many of the pioneering individuals had to transcend the boundaries of collectivism to actual make the world better. Tesla comes to mind.
IQ is not the only thing that improves. Different types of memory have improved over the same time periods.
Even from a theoretical perspective it doesn’t make sense that people who complete manual farm labor their entire life would be as intelligent as someone today who is educated for almost 2 decades.
I assume you never had to "complete manual farm labor [your] entire life". In truth, a dumb farmer is a dead farmer. If you're a farmer and you're dumb your crop fails and you can't eat, and if you can't eat you die.
I know you said (paraphrasing) "not as intelligent" rather than "dumb", but farmers today rely on science and technology developed by others to grow their crops and not lose their harvests. People in ancient times didn't have access to the same science and technology and they had to figure a lot out themselves. Staying alive, feeding your family and your community (or having your crops stolen by warlords and bandits, as it were) year after year, was a much harder test of intelligence than an IQ test, and with much higher stakes to boot.
But I think modern city-dwellers understimate the amount of intelligence it took, for example, to develop all the crops and farm animals we take for granted today. Since we're talking about Pre-Columbian Americas, think for a moment of all the staples of our diet that were developed by those ancient civilisations that didn't even have writing: potatoes, corn, tomatoes, eggplants, beans, pumpkins (from which courgettes are derived), bell peppers, sweet potatoes, and then cocoa, tobacco and coffee. And that's just the staples, by my own definition of foods I couldn't cook without.
And everywhere else you look in the world you find plants and animals that were developed by people who had no knowledge of genetics. They did it empirically, painstakingly, over generations. But they did it because they were just as intelligent as anyone trained as a scientist in modern times. If all those ancient farmers were not at least as intelligent as modern scientists, we wouldn't have the mad variety of food we have today.
All these were not developed by people who lacked intelligence, but I think you are right to suggest that an IQ test would find those people to be less intelligent than "someone today who is educated for almost 2 decades". But that is a bug, not a feature.
The intro says it all. Jared Diamond is a damn smart cookie. I don't know if he still works there, but he used to be a Harvard professor, so he hung out with a lot of smart cookies.
He wrote the book, because he was hanging out with New Guinea hunter-gatherers (I believe they hunted and gathered heads).
He realized that a lot of these folks were every bit as smart as his peers, and wanted to find out why they didn't come out of the scrum as a more advanced society.
https://www.goodreads.com/book/show/56269264-the-dawn-of-eve...
This one doesn't seem to have a lot behind it. There are a handful of nice coincidences, but that's all.
is Graham Hancock, who has written several famous books about the questions of what the loss of the library at Alexandria, to fire, did to the current ideas of history.
And Mayans are positively modern by the ancient timelines (e.g. Egypt is more ancient).
He gives evidence for shamanic influences at the origin of western civilization, namely through the friendship of Abaris and Pythagoras. Abaris was from the Steppes—and potentially from as far as Mongolia. He then speculates further about the shared cultural lineage between the Americas, which was populated by the steppe people circa up to 10k BCE, and the emergence of complex society around the Black Sea. A lot of speculation but all grounded in well-cited evidence. A short but fun read.