Can someone explain to me why none of the great apes that supposedly share so much with humans in terms of cognitive ability can be taught how to read and to write, not merely as a parlor trick that the creature utilizes so that it will receive some reward that might satisfy an immediate physiological craving such as hunger, but as a technique that the animal might use to communicate its own thoughts and ideas to others (can an ape write a creative story with a beginning, middle, and end, for example?), and in particular, be able to teach this ability to successive generations of apes who may then even surpass the ability of their own instructor? An ape that could read could then teach itself how to do many more things than what it currently knows simply by reading about them, rather than having to be explicitly instructed by someone else... it could learn the rules to a game like chess, for example.
Practically any human being can typically be taught how to read and to write by the time they are six or seven if the education is available to them. Can somebody tell me what, if anything, is so unique about the human mind that no other creature on the planet can be taught this?