My son is 18 months old, and I’ve been reading books with him since he was born. I say “reading”, but I really mean “looking at” – not to mention grasping, dropping, throwing, cuddling, chewing, and everything else a tiny human being likes to do. Over the last six months, though, he has begun not simply to look but also to recognise a few letters and numbers. He calls a capital Y a “yak” after a picture on the door of his room; a capital H is “hedgehog”; a capital K, “kangaroo”; and so on.Reading, unlike speaking, is a young activity in evolutionary terms. Humans have been speaking in some form for hundreds of thousands of years; we are born with the ability to acquire speech etched into our neurones. The earliest writing, however, emerged only 6,000 years ago, and every act of reading remains a version of what my son is learning: identifying the special species of physical objects known as letters and words, using much the same neural circuits as we use to identify trees, cars, animals and telephone boxes.
http://www.theguardian.com/technology/2015/feb/23/reading-writing-on-paper-better-for-brain-concentration