I think even in far limit higher IQ's stones will stay better on the sticks. It ain't easy to attach a stone to a stick well.

It doesn't require 16 years of education and then a PhD to master making spears or fire, especially when there's not a whole lot else to do; even if there were no ceiling, that still doesn't justify the extremely high calorie and protein consumption of a top-notch brain.

There's no point in me looking it up; I was a Boy Scout, I knew how to make and use a fire drill.

In some nearly tropical island, what is the great harm, exactly, in not being able to start the fire? Here you freeze to death in the first winter

It's not really a tropical paradise either.