Figure 1.

A case of collective knowledge generating more advanced behavioural solutions. In one of three groups not provided with a model demonstrating how to unfold a tube, unscrew a valve to open it and then shape it so it could be used as a straw to suck the juice from a container outside the enclosure mesh, this complex of actions nevertheless emerged through the collective actions of several individuals. In phase 1 two individuals unscrewed the valve but no more. In phase 2, collective solutions emerged through different individuals executing separate components of the whole sequence required. As chimpanzees further observed these in phase 3, two individuals combined them and thence mastered the task. For further explanation and discussion, see text.