The Emergence of Stone-Tool Use in Captive Chimpanzees

Abstract

We outline in this chapter three studies that focused on the emergence and learning of stone-tool use to crack nuts by captive chimpanzees. The first study illuminated the following challenges for chimpanzees in mastering the use of stone tools to crack nuts: the use of the hitting action, the shift of attention from nuts to stones, and the combinatory manipulation of three objects. The second study showed that the acquisition process can be broken down into several steps, including the recognition of the goal, the emergence of the use of a combination of three objects, the emergence of the hitting action, the use of a tool for hitting, and the hitting of the nut. Success was not brought about by random trial and error, but arises from the systematic understanding of this type of tool-use. The third study showed that, in favorable conditions, chimpanzees have the potential to acquire the skills to use stone tools to crack nuts before the age of 2 years, which is much earlier than indicated by studies in the wild.