(i) Speech and writing differ in their mechanics, of course, and that is one reason children must struggle with writing- it takes practice to reproduce the sounds of language with a pencil.
(ii) But the written word is a recent invention that has left no trace in our genome and must be laboriously acquired throughout childhood and beyond.
(iii) Man has an instinctive tendency to speak,as we see in the babble of our young children, whereas no child has an instinctive tendency to bake, brew or write.
(iv) The spoken word is order than our species, and the instinct for language allows children to engage in articulate conversation years before they enter a schoolhouse.
(v) But they differ in another way, which makes the acquisition of writing a lifelong challenge, even after the mechanics have been mastered.