They seem pretty intelligent for a people isolated before humans started farming.
They sound like geniuses compared to the cavemen down Papua New Guinea.
How come they don't all have down syndrome or big feet from all that inbreeding?
400 isn't a viable population size.
I guess inbreeding is a defect they don’t suffer from. There’s no way for a society to inbreed for thousands of years and still be around like this. They might not all have been direct relatives when they got to that island but years of isolation turned them all into close relatives yet I don’t see any inbreeding defects among them.
Maybe that’s one reason why population is low? You can only inbreed for so long on a tiny island before everyone eventually goes sterile ?