If the emergence of speech marks the greatest intellectual advance of our species, perhaps even defining Homo sapiens, then the invention of writing must be counted a cultural landmark almost equally as significant, for it is the printed word that has been the repository of knowledge and allowed its dissemination across space and time. Even today, in the modern world of computers and information technology, an inability to read can have profound social and psychological consequences (Maughan, 1995). Yet reading has been called an “unnatural act” (Gough & Hillinger, 1980) and the majority of the world’s population is functionally illiterate.