Are chimpanzees capable of language

Chimpanzees were the first to learn American Sign Language, which is considered a full-fledged language. The idea to teach them to communicate with their hands was first suggested as far back as the 17th century. However, it wasn't until the 1960s (based on the observation of a Primatologist active during the 1920s) that the Gardners, a husband-wife team of psychologists, began to teach American Sign Language to a young female chimp named Washoe. The results of their study were first published in 1969. A good book on the subject is Next of Kin: My Conversations with Chimpanzees (1997) by Roger Fouts.