Chimpanzees ( Pan troglodytes ) develop a successful communicative strategy to collaborate 1 2 3 4

23 24 Successful collaboration often relies on individuals’ capacity to communicate with each other. 25 Despite extensive research on chimpanzee communication, there is little evidence that chimpanzees 26 are capable, without extensive human training, of regulating collaborative activities via 27 communication. This study investigated whether pairs of chimpanzees were capable of 28 communicating to ensure coordination during collaborative problem-solving. The chimpanzee pairs 29 needed two tools to extract fruits from an apparatus. The communicator in each pair could see the 30 location of the tools (hidden in one of two boxes), whereas only the recipient could open the boxes. 31 The subjects were first successfully tested for their capacity to understand the pointing gestures of a 32 human who indicated the location of the tools. In a subsequent conspecifics test, the communicator 33 increasingly communicated the tools’ location, by approaching the baited box and giving the key 34 needed to open it to the recipients. The recipient used these signals and obtained the tools, transferring 35 one of the tools to the communicator so that the pair could collaborate in obtaining the fruits. The 36 study suggests that chimpanzees have the necessary socio-cognitive skills to naturally develop a 37 simple communicative strategy to ensure coordination in a collaborative task. 38 39 40 41