Can apes learn language?
Apes cannot speak - their mouths and throats are too different from ours. But in the 1960s, several chimpanzees were taught to use sign language. One, called Washoe, appeared to have learnt 160 words by the age of four. However, critics said that Washoe and the other signing chimps were just copying their instructors to get rewards. The bonobo, or pygmy chimpanzee, seemed to have greater language ability. Using special keyboards, which have symbols representing words, they showed that bonobos can learn some aspects of language.