Honestly it's kinda impressive that more than half of Americans have read a book in the last 12 months. I mean I read a book, but that's just so I have an answer in case anyone asks if I've read any books lately.
I also hate "reading a book" as a proxy metric for intelligence. I know plenty of cultured smart people who watch documentaries but don't read. And I know some dense, not that bright people who read a lot of Twilight style books.
Reading Twilight demonstrates the ability to focus on a task for a long time, which is more that can be said for people watching documentaries (I watch a lot of them).
Sure. but there are plenty of reasons to not read other than "uneducated". And associating ability to focus with intelligence and education isn't fair either.
If an American couldn't tell me how many states there are, I would question their intelligence or education.
If an American told me that they don't read books, I would just assume they find books boring.