Fifteen Eighty Four

How is it that any child, anywhere, can acquire any of the world’s estimated 6,000 languages, in a matter of only a few years? This mystery has long intrigued scholars as well as those who take care of young children.  Each of these thousands of languages varies from each of the others in many ways—for example, not only in their words, but in the order and combination and recombination of words, phrases and clauses. They vary in the systems by which their specific grammars are created.  Based on these systems, the child who has acquired language, any language, can and does create an infinite set of possible sentences and combinations of sentences in order to create infinite possibilities for thought and communication. How can a child master this complex knowledge and do so across such diverse complexity and under such varying conditions of acquisition?

In our book we address this mystery by studying children’s acquisition of an essential aspect of language creation: relativization. The computation of relativization underlies the essential human competence to refine the specification of a referent, and to combine one clause in another, as in English relative clauses such as  “Big Bird pushes the balloon [which bumps Ernie],” or French, such as  “Mickey lit le livre [qui amuse Fifi]” (Mickey reads the book that amuses Fifi) or Tulu such as “[tetti-dii-ND-ataa]  aa koori boldu-(u) -NDu” (The hen that laid an egg/eggs is white).

As we review in our book, relativization forms vary widely across languages of the world and also within these languages. All forms of relativization reflect the essential power of language to develop and extend thought.

In this book, we present closely related experimental studies of children’s speech in three diverse languages: English (Germanic language family), French (Romance), and Tulu (Dravidian).  Using experimental controls and shared designs and methods, we ask: is there a shared developmental ordering across these three diverse languages? Do syntactic or semantic factors appear to determine this ordering? Are there shared constraints on developmental ordering?  We report data addressing each of these questions.

We develop and test hypotheses based on linguistic theory of grammatical systems underlying relativization. We ask to what degree, and how, specific principles of Universal Grammar (UG) determine developmental ordering in relativization acquisition over and above language diversity, and how and where language variation requires developmental experience.

Our cross-linguistic results reveal a continuous constraint on language acquisition across the three languages we study, in spite of their diversity in target adult relativization forms. We identify a shared developmental precursor in relativization acquisition, which is formalized by UG—a precursor that underlies the course of development of diverse languages. In both our quantitative and qualitative findings, children are not limited to observing and learning surface phenomena. Instead, they consult abstract principles and assemble linguistic components to create a language-specific grammar in creative ways.  We introduce a concept of “grammatical transparency” by which grammatical systems support language learnability.

Our results bear on the strong hypothesis that UG guides and constrains language acquisition, rendering the fundamental mystery tractable. At the same time, the results explicate a theory of UG’s effect on language acquisition, providing empirical evidence of how its principles underlie creation of a specific language grammar over time.

These results are consistent with both empirical and theoretical studies of language change, and with studies of multilingualism, suggesting that grammatical transparency also characterizes the acquisition of multilingualism in children and adults.

We propose a wider view of change, development, and language experience, guided by the human Language Faculty.