The robustness of learning through overhearing.

Two studies examined the robustness of vocabulary learning through overhearing by testing 48 2-year-olds in contexts in which a potentially distracting activity was present (Studies 1 and 2) and in which the novel word was embedded in a directive rather than a labeling statement (Study 2). The children were equally good at learning a novel object label when there was no distracting activity as when there was. They were also able to learn the word when the object was not explicitly labeled. These findings suggest that young children are keen observers of third-party interactions and that their linguistic input consists of more than just speech directly addressed to them.