Are professional writers, on average, more intelligent than the average person? Or do most writers who appear to be more intelligent only seem so because of how well they choose and use their words?

I'm more inclined to believe that they're not any smarter, on average, than the rest of us. If we were all just as clever with words, and we all had equal ability to translate our thoughts into words, I imagine we'd be surprised about who appears more intelligent than the rest of us.