Here’s Steven Pinker’s fascinating lecture The Stuff of Thought. He explains how the way we use language sheds light onto how we think and feel. In particular, he explains why certain kinds of words evoke such strong emotions that you can’t say them on television or over the radio.
Many Americans believe that apes can be taught to speak in sign language. In the movie the Rise of the Planet of the Apes, an orangutan that had been a “circus ape” could converse in American Sign Language, even though he had not yet undergone the intelligence-boosting transformation. In reality, Homo sapiensis the only living species that can really talk, whether in an oral language or in ASL. You can train some animals, such as apes or parrots, to give certain kinds of gestures or vocalizations in response to certain prompts. Yet unlike practically any human toddler, apes and parrots can never hold real conversations. Why can children converse whereas chimpanzees and orangutans and parrots cannot? It all boils down to grammar. Human beings can grasp it, and other animals cannot.