Acquisition by a pigtail macaque of behavior patterns beyond the natural repertoire of the species.

A female Macaca nemestrina was toilet trained at the age of 8 months and has learned to control urination at will. Giving is used by the monkey as a means of social manipulation but never in an altruistic context. An analysis of the constraints on learning to control elimination and to give in nonhuman primates shows that only certain components of these behaviors are contraprepared. A hypothesis for the origin of giving in Hominids is proposed, and attention is drawn to the opportunity for studying voluntary behavior in monkeys.