title: Food-exchange with humans in brown capuchin monkeys.
abstract: To assess how brown capuchin monkeys (Cebus apella) delay gratification and maximize payoff, we carried out four experiments in which six subjects could exchange food pieces with a human experimenter. The pieces differed either in quality or quantity. In qualitative exchanges, all subjects gave a piece of food to receive another of higher value. When the difference of value between the rewards to be returned and those expected was higher, subjects performed better. Only two subjects refrained from nibbling the piece of food before returning it. All subjects performed two or three qualitative exchanges in succession to obtain a given reward. In quantitative exchanges, three subjects returned a food item to obtain a bigger one, but two of them nibbled the item before returning it. Individual differences were marked. Subjects had some difficulties when the food to be returned was similar or equal in quality to that expected.
authors.affiliation: Centre d'Ecologie, Physiologie et Ethologie, Centre National de la Recherche Scientifique, UPR 9010, Strasbourg, France.
authors.forename: Maud
authors.initials: M
authors.lastname: Drapier
authors.forename: Christophe
authors.initials: C
authors.lastname: Chauvin
authors.forename: Valérie
authors.initials: V
authors.lastname: Dufour
authors.forename: Pierre
authors.initials: P
authors.lastname: Uhlrich
authors.forename: Bernard
authors.initials: B
authors.lastname: Thierry
mesh_terms: D000818:Animals; D002428:Cebus / Q000502:physiology*; D003299:Cooperative Behavior; D003657:Decision Making / Q000502:physiology; D005247:Feeding Behavior / Q000502:physiology*; D005518:Food Preferences; D006801:Humans; D019370:Observation; D012201:Reward; D012919:Social Behavior