title: Production and Comprehension of Gestures between Orang-Utans (Pongo pygmaeus) in a Referential Communication Game.
abstract: Orang-utans played a communication game in two studies testing their ability to produce and comprehend requestive pointing. While the 'communicator' could see but not obtain hidden food, the 'donor' could release the food to the communicator, but could not see its location for herself. They could coordinate successfully if the communicator pointed to the food, and if the donor comprehended his communicative goal and responded pro-socially. In Study 1, one orang-utan pointed regularly and accurately for peers. However, they responded only rarely. In Study 2, a human experimenter played the communicator's role in three conditions, testing the apes' comprehension of points of different heights and different degrees of ostension. There was no effect of condition. However, across conditions one donor performed well individually, and as a group orang-utans' comprehension performance tended towards significance. We explain this on the grounds that comprehension required inferences that they found difficult - but not impossible. The finding has valuable implications for our thinking about the development of pointing in phylogeny.
authors.affiliation: Department of Developmental and Comparative Psychology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Saxony, Germany; Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin, Germany.
authors.forename: Richard
authors.initials: R
authors.lastname: Moore
authors.affiliation: Department of Developmental and Comparative Psychology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Saxony, Germany; School of Psychology and Neuroscience, University of St Andrews, St Andrews, Fife, Scotland.
authors.forename: Josep
authors.initials: J
authors.lastname: Call
authors.affiliation: Department of Developmental and Comparative Psychology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Saxony, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Tomasello
mesh_terms: D000819:Animal Communication; D000818:Animals; D005260:Female; D005868:Gestures; D008297:Male; D011148:Pongo pygmaeus