I think kids today are smarter than they give them credit for. Otherwise, the comics aimed at kids and considered "all-ages" wouldn't be dumbed down to 2nd grade level storytelling. Look at regular books that truly appealed to a wide range of ages from pre-teens to adults such as Harry Potter and you'll see a surprising amount of sophistication without resorting to curse words, sexual innuendo or scatalogical humor.

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Both ends of the spectrum seem dumbed down. The so-called all-ages books are written for children and the "teen and adult" titles don't have anything of intelligent substance going on in them either. They lose on both counts.