Bizarre fact department:
Perhaps nothing is more unexpected about our brains than that they are much smaller today than they were ten thousand or twelve thousand years ago, and by quite a lot. The average brain has shrunk from 1,500 cubic centimeters then to 1,350 cubic centimeters now. That’s equivalent to scooping out a portion of brain about the size of a tennis ball. That’s not at all easy to explain, because it happened all over the world at the same time, as if we agreed to reduce our brains by treaty.
Bryson, Bill. The Body (p. 70). Knopf Doubleday Publishing Group. Kindle Edition.
That is pretty weird, but is it just coincidence that agriculture was invented and spread the world about that time? The resultant simplification in ways of making a living might have made some brain size reduction an advantageous evolutionary development. The brain is a very hungry organ, and consumes a whole lot of nutrition.
It might also explain Republicans.