Abstract

Chimpanzees’ use of gesture was described in the first detailed field study [1Goodall J. The Behavior of Free-Living Chimpanzees in the Gombe Stream Reserve (Animal Behaviour Monographs 1:3). Baillière, Tindall & Cassell, London1968: 163-311Google Scholar, 2Plooij F.X. Some basic traits of language in wild chimpanzees.in: Lock A. Action, Gesture, and Symbol: The Emergence of Language. Academic Press, London1978: 111-131Google Scholar], and natural use of specific gestures has been analyzed [3McGrew W.C. Marchant L.F. Scott S. Tutin C.E.G. Intergroup differences in a social custom of wild chimpanzees: the grooming hand-clasp of the Mahale Mountains, Tanzania.Curr. Anthropol. 2001; 42: 148-153Crossref Google Scholar, 4Nishida T. The leaf-clipping display: a newly-discovered expressive gesture in wild chimpanzees.J. Hum. Evol. 1980; 9: 117-128Crossref Scopus (113) Google Scholar, 5Matsumoto-Oda A. 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Serial gesturing by wild chimpanzees: its nature and function for communication.Anim. Cogn. 2011; 14: 827-838Crossref PubMed Scopus (97) Google Scholar]. All of these aspects overlap with human language but are apparently missing in most animal communication systems, including great ape vocalization, where extensive study has produced meager evidence for intentional use ([20Rendall D. Owren M.J. Ryan M.J. What do animal signals mean?.Anim. Behav. 2009; 78: 233-240Crossref Scopus (270) Google Scholar], but see [21Crockford C. Wittig R.M. Mundry R. Zuberbühler K. Wild chimpanzees inform ignorant group members of danger.Curr. Biol. 2012; 22: 142-146Abstract Full Text Full Text PDF PubMed Scopus (242) Google Scholar, 22Schel A.M. Townsend S.W. Machanda Z. Zuberbühler K. Slocombe K.E. Chimpanzee alarm call production meets key criteria for intentionality.PLoS ONE. 2013; 8: e76674Crossref PubMed Scopus (187) Google Scholar]). Findings about great ape gestures spurred interest in a potential common ancestral origin with components of human language [23Hewes G.W. Primate communication and the gestural origin of language.Curr. Anthropol. 1973; 33: 65-84Crossref Google Scholar, 24Armstrong D. Stokoe W. Wilcox S. Gesture and the Nature of Language. Cambridge University Press, Cambridge1995Crossref Google Scholar, 25Corballis M. From Hand to Mouth: The Origins of Language. Princeton University Press, New Jersey2002Crossref Google Scholar]. Of particular interest, given the relevance to language origins, is the question of what chimpanzees intend their gestures to mean; surprisingly, the matter of what the intentional signals are used to achieve has been largely neglected. Here we present the first systematic study of meaning in chimpanzee gestural communication. Individual gestures have specific meanings, independently of signaler identity, and we provide a partial “lexicon”; flexibility is predominantly in the use of multiple gestures for a specific meaning. We distinguish a range of meanings, from simple requests associated with just a few gestures to broader social negotiation associated with a wider range of gesture types. Access to a range of alternatives may increase communicative subtlety during important social negotiations.