Brain size is not directly related to inteligence. We are the smartest animals on our planet, (I know people are going to argue this but show me a dolphin that understands chaos theory or an ape that can build a waste management system) but other animals are known to have larger brains. Ergo, not a factor in inteligence.
It's leveling off, stabilizing in other words. Because clearly it hasn't affected the average intelligence, of course some people beg to be an example of it affecting them.
Id say the use of technology and modern living is making us stupid. We hardly need skills we needed before to survive, so the evolution is giving up on many traits that are no longer necessary.
Lol No, our critical thinking skills are used differently. Problem solving other things, instead of how to take down the mammoth/bison/buffalo. Except for those good Ol' boys in the orange vests and camo lolContrary to belief, technology causes more complicated problems while taking other problems away. Just ask any IT guy at a office.