Abstract

Across languages, infant/child-directed speech contains a number of register-specific words and wordforms, such as 'choo-choo', 'tummy' and 'doggy'. These words, also known as 'baby-talk words,' are often lexically redundant and antithetic to the principle of contrast (e.g., 'choo-choo' and 'train' are hardly distinguishable in meaning). They also tend to share common characteristics such as a high degree of iconicity, diminutives and sound repetition, some of which are not typical of the rest of the lexicon. In this talk, I discuss some explanations for the ubiquity and the shared characteristics of baby-talk words, drawing on the results of typological, experimental and longitudinal studies that we have carried out on the impact of the relevant lexical features on word segmentation, learning and production. Taken together, the results of these studies suggest that some of the features found in baby-talk words are facilitative of early lexical development and that register-specific lexical items in infant-directed speech may be shaped and maintained in languages in response to the functional pressure to provide infants a gateway to vocabulary learning.