Symbolic Communication Between Two Chimpanzees ( Pan troglodytes )

Abstract
Through use of learned symbols, two chimpanzees accurately specified 11 foods by name to one another when the food item's identity was known by only one. They could not do this when denied use of the symbols. The chimpanzees then spontaneously requested specific foods of one another by name. Requests resulted in cooperative and reciprocal symbolically mediated food exchange.