Interesting thread! I'm actually familiar with almost all of the research you mentioned.. And I was getting ready to respond about Einstein and then at the very end noticed you covered that as well.

I wouldn't necessarily say brain size is what's more important, but the connections and how the brain is wired together and.. Look at computers, they keep getting smaller and smaller, maybe if evolution happened as decribed by many, the shrinking of the brain might also been an evolution, like.. It's figuring out how to do more with less per se.

Who knows though.. I think the Idiocracy theory is a good theory, though.. You could have a big brain and still be really stupid and you can have a smaller brain and be super smart.. So.. I don't necessarily think size is as crucial as many seem to make it seem to be.