 In a similar study, chimps were provided with a preference box with two compartments, one containing a picture of food, the other containing a picture of nothing (the pictures had no causal relation to the contents).In a foraging competition game, chimpanzees avoided the chamber with the picture of food when their competitor had chosen one of the chambers before them.The authors suggested this was presumably on the assumption that the competitor shared their own preference for it and had already chosen it.