Academic literacy has three components: (1) academic language, (2) content knowledge, (3) analytic thinking ability. The traditional approach has been direct instruction in (1) and (2) and the assumption that (3) happens as a result of traditional subject matter teaching.
I hypothesize that we acquire (1) academic language from self-selected reading, not from study of vocabulary, grammar or text structure. This includes reading fiction, which has been shown to contain substantial amounts of academic vocabulary. Reading fiction also contributes to (2), content knowledge. Those who read more fiction know more about academic topics such as science, history, and literature. Writing contributes to (3) analytic thinking, especially in the use of revision, a powerful way of arriving at deeper and better ideas.