I’m a little (well, a lot) appalled that challenging the assumption that "language … allows you to do other high order intellectual functions" is considered so shocking. I frequently feel like language gets in the way of my high order thoughts, in an analogous way to how sounding the words in my head slows down my reading. It’s like making the thoughts into words is this bad habit that I can’t figure out how to break.
I’m inclined to believe there’s a spectrum of verbal thought: I can at least imagine thought without words, which I think puts me somewhere in the middle. At one end, there’s Temple Grandin, who helped design the cow-calming slaughter trail and does not think verbally at all (cf. autism); and at the other, someone I know expressed unwillingness to believe that non-verbal thought exists. The punch line? The latter person is a graphic designer.