Labels affect preschoolers' tool-based scale errors

- When tools are labeled, preschoolers make more scale errors.
- Labels offset task experience, leading to high error rates in a second test trial.
- Tool familiarity does not change the effect of labels of scale errors.
- Language shapes how children act on objects.

Scale errors offer a unique context in which to examine the interdependencies between language and action. Here, we manipulated the presence of labels in a tool-based paradigm previously shown to elicit high rates of scale errors. We predicted that labels would increase children's scale errors with tools by directing attention to shape, function, and category membership. Children between the ages of 2 and 3 years were introduced to an apparatus and shown how to produce its function using a tool (e.g., scooping a toy fish from an aquarium using a net). In each of two test trials, children were asked to choose between two novel tools to complete the same task: one that was a large non-functional version of the tool presented in training and one novel functional object (different in shape). A total of four tool-apparatus sets were tested. The results indicated that without labels, scale errors decreased over the two test trials. In contrast, when labels were present, scale errors remained high in the second test trial. We interpret these findings as evidence that linguistic cues can influence children's action-based errors with tools.