How 2-year-old children learn novel part names of unfamiliar objects.

The present study examined whether 2-year-olds can learn a novel part name of an unfamiliar object when an adult demonstrates an action upon a part of the object. In the experiment, an experimenter pointed at, named, and acted upon a certain part (nut) of an unfamiliar object (a u-shaped bolt with a nut) or simply pointed at and named the part. Twenty-four Japanese 2-year-olds were asked to choose a referent for the given name in forced-choice tests. The results showed that children choose an isolated part (the nut) when the experimenter demonstrates an action upon the part. However, they choose a whole object of similar shape (a u-shaped bolt without a nut) when the experimenter does not demonstrate such an action. The study suggests that young children are able to 'override' the whole object assumption (Markman, E.M., Wachtel, G.F., 1988. Cognitive Psychology 20, 121-157) when they observe adults' actions on parts of objects.