"The thing was that earth was the only place in the whole known Universe where language was used. It was a unique Earthling invention. Everybody else use mental telepathy, so Earthlings could get pretty good jobs as language teachers just about anywhere they went.
The reason creatures wanted to use language instead of mental telepathy was that they found out they could get so much more done with language. Language made them so much more active. Mental telepathy, with everybody constantly telling everybody everything, produced a sort of generalized indifference to all information. But language, with its slow, narrow meanings, made it possible to think about one thing at a time - to start thinking in terms of projects.”" – Kurt Vonnegut, God Bless You, Mr. Rosewater. Cited in Jackendoff, 2012, p. xi (via leakygrammar)