USE OF EXPERIMENTER-GIVEN CUES DURING OBJECT CHOICE TASKS BY CAPUCHIN MONKEYS

Three capuchin monkeys, Cebus apella, were tested on object-choice tasks in which the correct (i.e. baited) object was indicated by the experimenter during the response period on half of all trials. Three cue conditions were used in five experiments: gazing at the correct object, gazing plus pointing, and pointing alone. The subjects did not use the experimenter's gazing at the correct object as a cue. In contrast, they did use gazing plus pointing, and the final experiment showed that pointing was necessary and sufficient under the conditions of the study. The ineffectiveness of the experimenter's gazing as a cue may be caused by reduced cue-response spatial contiguity, but it may also reflect a limitation of mental or visual perspective-taking in these monkeys.