Symbol Combination in Pan: Language, Action, Culture

This talk will be based on research carried out with two bonobos and one chimpanzee at the Language Research Center in Atlanta; it is a collaboration with Heidi Lyn, New York Wildlife Conservation Society, and Sue Savage-Rumbaugh, Georgia State University. Here are the conclusions; supporting data will be presented in the talk.

Apes exposed to a humanly-devised symbol system parse and represent action events in the way that children do. Also like children, they construct preferred orders for representing these action events.

These order preferences reflect both cultural norms and genus norms within our sample. Given the fact that both species of Pan adopt these arbitrary conventions, the capacity for such conventions may go back to the common ancestor of Pan and Homo. In this capacity may lie an origin of the autonomous structuring of the representational system that ultimately led to the arbitrary, yet distinct, norms of all human languages.

The apes' symbolic encoding of action shows an awareness of a human state of mind as a prerequisite to ape action.; they frequently used affirmatives to gain permission for a desired action. Our results indicate that this awareness increased over time in the community; these conventions are shared by the younger apes Panbanisha and Panpanzee, but were not utilized by Kanzi.

Apes exposed to a humanly devised symbol system integrated different communicative modalities into their communicative actions – specifically they integrated gesture and lexigram to express their action representations. Their spontaneous integration of gesture is part of a larger fact that apes utilize gestures so much more often that their human caregivers or human children. The creativity of the "gesture after lexigram" organization to construct new action relations could be an evolutionary precursor to the combinatorial creativity that is the hallmark of human language.

Cross-species comparisons of bonobos, chimpanzees, and humans permit basic cladistic analysis and provide evidence concerning the evolution of the communication and representation of action information. The cross-species commonalities in Pan paniscus, Pan troglodytes, and human children identified for the cognitive parsing of physical action may well have existed in our common ancestor seven million years ago.

Finally, given that communication of action information has been observed in the wild in gestures, vocalization, and external visual symbols utilized by apes, it is possible that the cross-species commonalities identified in the normative integration of gesture and symbol also have their roots back 5-7 million years ago.