What are the intrinsic differences between the literate and the illiterate mind? The Vai, a small West African group, developed their own system of writing that flourishes today, althought no body of written literature exists and about half of those literate in Vai have never had formal schooling. Given this situation, Scribner and Cole were able to test mor than 1,000 subjects over a four-year period to measure the mental advantage of literates over...