Figure 1.

Schematic representation of the set-up and the apparatus in the child and chimpanzee experiments. In each condition, the subject—located in front—could choose one of two options. (a) Test condition: children and chimpanzees could either select a 2–1 or a 3–6 distribution, depicted on the left side of the image. (b) Control condition: children and chimpanzees could either select a 2–5 or a 3–6 distribution, depicted on the right side of the image. (Online version in colour.)