Infants and children are remarkably adept at learning language, much more adept in fact than their parents. Until recently, two theories competed to explain the language learning skill of young children. In one view, infants and children are like sponges, soaking up every detail of their environment, including the linguistic environment. In a competing view, infants come into the world with the range of human languages (or grammars) already "built-in." Their linguistic environment serves only to allow them to select the particular grammar of their native language, such as what speech sounds will be used, whether verbs come in the middle or the end of sentences, etc. Recently, a third view has begun gaining support. This view shares the position of the first view that infants and children are highly sensitive to every detail of their environment. It shares the position of the second view that infants and children have as their goal determining the particular linguistic system or grammar of their community. One way to discriminate among these three theories is the amount and kind of input required for optimal language learning. The first "sponge" view (or Associative theories) suggests that a great deal of input is needed and that it does not matter much whether that input consists of many repetitions (tokens) of the same example (type; e.g., hearing the word dogs as the plural of dog multiple times) or different examples (e.g., hearing dogs, pigs, and mugs as the plurals of their respective singulars). The second "built-in grammars" view (or Innate Domain theories) suggests that extremely little input is needed and that even a single repetition of a single example is sufficient for the infant or child to learn a particular component of the native language. The third "grammar-seeking sponge" view (or Hypothesis Selection theories) suggests that a very small number (e.g., three) of different examples are needed for learning and that different examples are much more helpful than repetitions of an example. This project will compare these three theories by asking about the amount of input needed for language learning. It also attempts to embed the third theory in a more realistic model of human learners by asking if learning always improves as the number of examples increases, or whether there is a trade-off between the number of examples and the number of repetitions of each example.
This research will contribute to our scientific knowledge by asking whether humans are reflections of their environment, their biology, or whether and how the mind is a product of a biological brain with a primary goal of "making sense" of the environment. Moreover, because the research draws on existing studies of infant vision and infant social interaction, it places the study of language development in a broader developmental context. Finally, the research explores the specific kinds of input that maximize learning. Therefore, it has the potential to ultimately inform how we present linguistic and other information to infants, school children, and even adults in order to result in the best possible learning in the shortest possible time.
