Displaced reference

Signed and spoken human languages have the ability to refer to entities and events that are removed in space and/or time from the immediate communicative situation. Displaced reference has been documented in gesture used as a means of communication when the vocal channel is not available (cf. "Gesture"), particularly in the so-called "home sign" gestural systems that deaf children who are not exposed to sign language use to communicate with hearing family members. Co-speech gesture (cf. "Gesture"), a non-linguistic human communication system, can at times indirectly accommodate displaced reference. The only documented naturally occurring form of displaced reference in non-human species is the dance of forager honeybees, which is however limited to one type of referent only: distal food sources. Border collies have demonstrated the ability to comprehend reference to objects removed from the communicative situation under controlled conditions. Likewise, some language-trained apes have shown evidence of reference to displaced entities (objects, other familiar apes, people, locations) in either comprehension or production.