Experts from a US museum believe it could be one of the oldest examples of advanced surgery. The Museum of Osteology in Oklahoma said the skull is reported to have been that of a man who was injured in battle before undergoing surgery to implant a piece of metal in his head to repair a fracture.
In reality intelligence was about the same, just less existing knowledge to stand on.
It's not individual intelligence, it's access to knowledge.
Every big leap forward in human society has been about how far/fast ideas can be exchanged.
When that happens, suddenly all types of other advancements happen and then slow down over time till the next leap in communication.
The biggest thing humans have going for us, is it only takes one human to figure something out these days.
Standing on the shoulders of giants.
Actually the opposite.
All those famous early scientists were just the only ones with access to libraries or even the ability to read back then.
They figured a bunch of shit out, but it's because they were the only ones with the time and resources to sit around and bounce ideas off each other.
If you only educate like 0.01% of the population, you shouldn't be surprised when that who comes up with innovation.
But your odds are better if you educate everyone, and then throw the smartest together. Rather than just hoping the rich upper class has a couple smart people this generation.
Unfortunately the current leap in communication today is tik tok and AI controlled short videos.
The other alternative leap in communication was meta.
Tough to say what existing knowledge there was after the Spaniards saved them.
"saved"
I would argue that intelligence is different than exploration. We now have amassed so much recordable knowledge across so many disciplines. In the past those that remembered this knowledge correctly or where to find it were the intelligent ones. Now it's how we use it. It's a drastic pivot point in human history and the computer is the center piece.