Token transfers among great apes (Gorilla gorilla, Pongo pygmaeus, Pan paniscus, and Pan troglodytes): species differences, gestural requests, and reciprocal exchange - Pelé, Marie; Dufour, Valérie; Thierry, Bernard; Call, Josep (Journal of comparative psychology (Washington, D.C. : 1983), 2009)
Keywords: Animal Communication; Animals; Appetitive Behavior; Comprehension; Concept Formation; Female; Gestures; Gorilla gorilla - psychology; Humans; Intention; Male; Motivation; Nonverbal Communication; Pan paniscus - psychology; Pan troglodytes - psychology; Pongo pygmaeus - psychology; Reward; Social Behavior; Species Specificity