In his ZiF-Public Lecture on Tuesday, 4 July 2006 the renowned anthropologist Michael Tomasello, Director at the Max Planck Institute of Evolutionary Anthropology Leipzig, will explain that each of the great apes species has a rich and varied repertoire of communicative gestures. But virtually all of these gestures are dyadic - concerning the immediate social interaction of sender and receiver - and imperative - concerning things the sender wants the receiver to do.
In contrast, from before language begins human infants communicate triadically about external objects and events. And they do so for both declarative and informative motives, that is, in order to share attention or information with another. Soon after that they begin to communicate with conventional linguistic symbols, whose bi-directional nature is specially built for sharing and collaboration. This comparison between apes and prelinguistic and just-linguistic human infants suggests that a crucial component in the evolution of human linguistic communication is the motive and capacity for sharing experience and getting things done collaboratively.