Research into great ape language has involved teaching chimpanzees, bonobos, gorillas and orangutans to communicate with humans and each other using sign language, physical tokens, lexigrams, and imitative human speech. Some primatologists argue that the use of these communication methods indicate primate "language" ability, though this depends on one's definition of language. The cognitive tradeoff hypothesis suggests that human language skills evolved at the expense of the short-term and working memory capabilities observed in other hominids.
Facial expressions can be used to convey a message.
Kanzi has learned hundreds of arbitrary symbols representing words, objects, and familiar people (including the generic "Visitor").
Language is a structured system of communication that consists of grammar and vocabulary. It is the primary means by which humans convey meaning, both in spoken and written forms, and may also be conveyed through sign languages. Human language is characterized by its cultural and historical diversity, with significant variations observed between cultures and across time. Human languages possess the properties of productivity and displacement, which enable the creation of an infinite number of sentences, and the ability to refer to objects, events, and ideas that are not immediately present in the discourse. The use of human language relies on social convention and is acquired through learning.
A mural in Teotihuacan, Mexico (c. 2nd century) depicting a person emitting a speech scroll from his mouth, symbolizing speech
Cuneiform is the first known form of written language, but spoken language predates writing by at least many tens of thousands of years.
Children of deaf adults using American Sign Language
Braille, a tactile writing system
