http://www.nytimes.com/2015/05/17/opinion/sunday/let-the-kids-learn-through-play.html?_r=1 By David KOHN, May 2015, Sunday Review, extract :

Reading, in particular, can’t be rushed. It has been around for only about 6,000 years, so the ability to transform marks on paper into complex meaning is not pre-wired into the brain. It doesn’t develop “naturally,” as do other complex skills such as walking; it can be fostered, but not forced. Too often that’s what schools are trying to do now.