Figure 4

(a) Species differences: dog puppies and wolf pups interacted more likely with the object than kittens; (b) species-specific effects of condition (experimental condition, E, illustrated with solid, and ghost condition, G, with dotted line) on the probability of interacting with the object in dog puppies, kittens and wolf pups: kittens and, to a lesser extent, also wolf pups (but not dog puppies) interacted with the object more likely in the ghost trials than in the experimental trials.