Push or pull: Imitation vs. Emulation in great apes and human children

All four species of great apes and young human children (12-24 mo of age) were administered an imitation task designed to distinguish between results learning (emulation) and action learning (imitation). Some subjects were exposed to a demonstrator either pushing or pulling a door to open a box, whereas others simply saw the door of the box opening itself in one of the two directions (the ghost control). Most of the apes successfully opened the box in both experimental conditions, as well as in a baseline condition, but without being influenced either by the demonstrator's actions or by the door's motions. In contrast, human children over 12 mo of age were influenced by the demonstration: the 18-mo-olds were influenced by the demonstrator's actions, and the 24-mo-olds were influenced both by the demonstrator's actions and by the door's motions in the ghost control. These results provide support for the hypothesis that human children have a greater propensity than great apes for focusing either on a demonstrator's action or on the result of their action, as needed, in social learning situations.