Innovation in a tool-manufacturing task in capuchin monkeys (Sapajus spp.).

Innovation has been defined as the ability to find a solution to a novel problem by using motor and cognitive strategies already acquired, or to find a novel solution to an old problem by using new motor and cognitive strategies. This ability can have important fitness consequences allowing animals to adapt flexibly to social and ecological changes, but it could also be detrimental exposing animals to potential risks and costs. Little is known about how this capacity emerges and whether/how innovators differ from non-innovators. The major aim of the study was to investigate the innovation capabilities of capuchin monkeys and 4-year-old children towards a task requiring tool-manufacturing. Here we report, the results concerning the sixteen capuchins presented with an innovative tool-manufacturing task in which they had to modify a tool to obtain a reward from a transparent apparatus. Each individual received three trials: in each trial three different material sets were presented to the subject. Each set consisted of four potential tools; if appropriately modified and used into a different opening in the apparatus, each tool provided the opportunity to reach the reward. Thirteen out of sixteen capuchin monkeys were able to modify objects to use them as tools to obtain the reward. Successful innovators differed from unsuccessful innovators in the amount of interaction with the apparatus and the tools but not in the latencies to approach the task stimuli. Moreover, previous experience in tool-use tasks affected success and time needed to solve the task. These results offer interesting insights into which factors influence innovative tool behavior in primates.