I would have to contest this. Although the Kalahari bush people may use
more brain power than
Joe-average-on-couch-drinking-beer-watching-Gilligans-Island-reruns, I find
it difficult to compare their usage of brain power to the technically
sophisticated parts of modern society. It was not that long ago that we
were lamenting how soon technological progress would exceed the rate at
which even the most intelligent technophiles could advance.
Granted, you used the word "survive", but I would submit that soon one will
not be able to "survive" in the modern world without exercising high amounts
of technical expertise. Certainly the individuals who are surviving best in
the world of rapid technology advancements are those who are show immense
adaptive intelligence. Vast improvements in intelligence will be THE
defining feature in the progress of the human species.