Finding the points of contact:: Language acquisition in children raised in monolingual, bilingual, and multilingual environments

The rapidly increasing number of children being raised in bilingual and multilingual homes and communities raises important questions and serious challenges for researchers, educators, and policy-makers. This paper offers fundamental findings from basic psychological research on early monolingual acquisition as a springboard to identify future points of contact with research from bilingual or multilingual perspectives. Using the cross-linguistic developmental approach to study early word learning and its relation to conceptual organization, I have focused exclusively on monolingual acquisition in infants and young children. The field has accumulated considerable evidence concerning early linguistic and conceptual development in both in Englishspeaking monolinguals and in monolingual children acquiring languages other than English. Armed with this evidence, the field is now poised to launch a full research agenda that focuses squarely on language acquisition in bilingual and multilingual children. In this commentary I outline some possible goals of such an agenda. The time has come to consider carefully the course of language and conceptual development in children raised in monolingual, bilingual, and multilingual environments. Building a truly developmental program of research on this topic will enrich our theories of acquisition even as it advances our educational and social goals. The rapidly increasing number of children being raised in bilingual and multilingual homes and communities raises important questions and serious challenges for researchers, educators, and policy-makers alike. In this article, I will focus on a few fundamental findings that have emerged from basic psychological research on early language acquisition in monolingual children, and will use this as a springboard to identify some future points of contact for research on language acquisition from monolingual, bilingual or multilingual perspectives. In my own research laboratory, I have adopted a cross-linguistic developmental approach to studying early word learning and its relation to conceptual organization, and I have focused exclusively on acquisition in infants and young children who are in the process of acquiring a single language. Although on the face of it, word learning in this population would appear to be a rather straightforward task, a more careful examination reveals that there are layers of complexity in this task. In fact, to be successful word learners, infants must (a) parse the relevant word from the continuous speech stream, (b) identify the relevant concept in the world, and (3) establish a mapping between them. See (Waxman & Lidz, in press) for a full discussion. More difficult still, there are many different words – indeed many different kinds of words – that can all be correctly applied to the very same scene or event in the world, and each kind of word directs attention to a different aspect of that experience. Consider for example a flamingo that is running behind a bluff. As speakers of English, we know that a count noun (“It’s a flamingo”) will refer to an individual object and can be extended to other members of the same object category (e.g., other flamingos), but that a proper noun (“That is Frieda”) will refer to an individual but cannot be extended further. In contrast to these words that can refer to the individual qua individual, adjectives (“She’s so graceful (or pink)”) do not refer to the individual itself, but rather to a property of an individual (or category), and adjectives are extended to other entities sharing that property, independent of the category membership (e.g., “pink” can be used to describe a flamingo, a coffee cup and a t-shirt). Research with monolingual children has shown that by 2 years of age, they are quite sensitive to many of the links between kinds of words (e.g., nouns, adjectives, verbs) and kinds of meaning (e.g., roughly speaking, the object categories, object properties, actions). In essence, they have discovered the relevant linguistic units (words and grammatical categories) as well as the relevant conceptual units (individual objects, categories of objects, properties of objects, and actions or relations among objects). More to the point, the evidence suggests that children as young as two years of age have also gathered some rather precise expectations about the mappings between these linguistic and conceptual units. As a result, they can use the grammatical form of a novel word as a clue to discovering its meaning (Hall & Lavin, 2004; Markman & Jaswal, 2004). Cross-linguistic investigations offer some important perspective on how these links between linguistic and conceptual units might be acquired (Gathercole & Min, 1997; Waxman, 2004). These investigations reveal that languages differ not only in the words that they use (chien vs dog), but also in the grammatical forms that are represented in the language and the way these forms are recruited to convey meaning. For example, although the grammatical distinction between count nouns (e.g., This is a dog) and proper nouns (e.g., This is Magic) is quite clear in English, this is not the case in Japanese, where the grammatical distinction between these two forms is scant, at best (Imai & Haryu, 2004). Nonetheless, speakers of both languages – indeed speakers of any human language -can use the resources of their language to distinguish between categories of objects and individual objects. As another example, there are differences in the kinds of meaning that are permissible for adjectives in English and French, on the one hand, as compared to Spanish and Italian on the other (Waxman & Guasti, in preparation; Waxman, Senghas, & Benveniste, 1997). Therefore, these links between kinds of words and their associated kinds of meaning must be shaped by the structure of the particular language under acquisition. With a clear view of these issues, the developmental question becomes: How do infants discover which grammatical forms are represented in their language, and how do they learn to map these linguistic forms to meaning? In my program of research, I have focused on these issues, asking which links, if any, are available early enough to guide the process of acquisition at the start, and how are these shaped by the language under acquisition. Any links that are available early in acquisition will be good candidates for universality; these may guide the initial stages of acquisition in all languages, and then become fine-tuned as the infant discovers the particular properties in the language being acquired. We have addressed these questions primarily with monolingual infants acquiring either English, Spanish, French, or Italian (Hall, Waxman, Bredart, & Nicolay, 2003; Waxman & Guasti, in preparation; Waxman et al., 1997). Our strategy has been to select particular links (e.g., the link between nouns and object categories, or between adjectives and object properties) and ask (1) when this link becomes available, (2) how each link is supported or shaped by the structure of the native language being acquired, and (3) how these various links unfold over the course of development. (See Waxman & Lidz, in press, for a review of the theoretical perspective and the empirical evidence supporting it.) We have argued that infants cross the threshold into word learning equipped with a powerful, but very general, expectation that links words and concepts. We have suggested that this broad initial link is universal, that it gets the process of word learning off the ground, and that it sets the stage for subsequent developments in the lexicon and in the grammar (Fulkerson & Haaf, 2003; Waxman & Markow, 1995). Of course, infants move beyond this initially broad link, and the evidence suggests that as they do, they first tease out the grammatical category noun from among the other grammatical forms, and map these specifically to individual objects and to categories of objects (Waxman, 1999). Only later do they tease apart the other grammatical forms in their language and discover their links to meaning. The early emergence of a noun-to-category link serves as the foundation that enables infants to discover the other essential grammatical forms that are present in their language (e.g., adjectives, verbs) and map these grammatical forms to their respective meanings. The patterns of acquisition for these latter forms appear to differ importantly from the acquisition of nouns, and appear to depend upon the prior acquisition of (at least some) nouns. This ‘cascading’ developmental picture, with nouns emerging early followed by the other grammatical forms, may well be universal, and may follow directly from the distinct informational requirements and conceptual entailments of each of these grammatical forms. We can take English as a case in point. Dana Markow and I (Waxman & Markow, 1995) used a novelty-preference design to discover whether infants harbor any links between linguistic and conceptual organization at 1214 months of age. This is the point at which most infants are just beginning to produce words on their own. During a familiarization phase, an experimenter offered the infant four different toys from a given object category (e.g., four animals), one at a time, in random order. This phase was immediately followed by a test phase, in which the experimenter simultaneously presented both a) a new member of the now-familiar category (e.g., another animal) and b) an object from a novel category (e.g., a fruit). Infants manipulated the toys freely throughout the task. We used the infants’ total accumulated manipulation time as the dependent measure. Each infant completed this task four times, with four different sets of objects. To identify any influence of novel words, infants were randomly assigned to one of three conditions that differed only during the familiarization phase of the experiment. Infants in the Noun condition heard, for exampl