Other Children, Other Languages

Issues in the theory of Language Acquisition

Yonata Levy

• Publisher: Psychology Press
• Year: 2013
• Print ISBN: 9780805813302
• eBook ISBN: 9781134776931
• Topic: Personal Development
• Subtopic: History & Theory in Psychology

This volume investigates the implications of the study of populations other than educated, middle-class, normal children and languages other than English on a universal theory of language acquisition. Because the authors represent different theoretical orientations, their contributions permit the reader to appreciate the full spectrum of language acquisition research. Emphasis is placed on the principle ways in which data from pathology and from a variety of languages may affect universal statements. The contributors confront some of the major theoretical issues in acquisition.

Chapter One

Introduction

Yonata Levy

The Hebrew University

Jerusalem

This book presents cross-linguistic and cross-population studies of language acquisition. In the history of research in the area of language acquisition, there were times when such a book would have been controversial. But for over a decade research has moved away to typo- logically diverse languages and to clinically varied populations in an effort to arrive at a generalized model of language acquisition.

The logic behind cross-linguistic studies is straightforward. Assuming a universal core to language, a position that most current theories take, cross-linguistic studies are necessary in order to establish potential candidates for universal, as well as for language-specific features. This is true not only for claims concerning Universal Grammar (Hyams, chap. 2; Roe- per & Seymour, chap. 10; Hoekstra, chap. 5) but also for approaches that argue for the primacy of conceptual distinctions in the early phases of language development (Schlesinger, chap. 4; Bloom, chap. 3), because the assumption that there is a universal core to language does not commit one as yet to what these universals might be. It does state, however, that human languages are similar in certain specific ways that crucially influence acquisition. This latter statement has to be tested in cross- linguistic contexts.

The logic behind the relevance of research in pathology to theories of normal acquisition is less direct. Pathologies may assume a multiplicity of forms, therefore one must decide on a general model within which they will be interpreted. The issue relates to congenital, or very early pathologies, as well as to later, acquired ones. However, it is mostly early pathologies occurring at the preverbal stage that are most relevant to language development; we therefore concentrate on these.

A possible framework within which to think about the relevance of pathology to normal acquisition is provided by the notion of plasticity. Generally speaking, plasticity states that the immature, partially differentiated brain has means of compensating for some critical deficiencies.

But how should the notion of plasticity be interpreted? Is it the claim that the eventual outcome of acquisition in children with brain pathologies is equivalent to that in normal children? Let us refer to this interpretation as “weak” plasticity. Alternatively, plasticity can be understood as referring to the final outcome, as well as to the developmental course. If both these are similar to normal we have a case of “strong” plasticity.

If evidence from pathology favors “strong” plasticity, then it will be relevant to models of normal development in a simple, straightforward way: The status of data from pathology will be identical to that of data from normal children (Levy, Amir, & Shalev, 1992). Apart from being an empirical validation of the notion of plasticity—not a small contribution in itself—there is a further, unique methodological advantage to such data, namely, because delay and slowness are the hallmarks of pathology, a protracted period of acquisition may offer new opportunities for a separation of variables in the course of development.

However, if the evidence favors “weak” plasticity, then this would present serious conceptual difficulties for theories that assume the existence of innate constraints that have a crucial role in acquisition, such as the theory of Principles and Parameters (Chomsky, 1986). This is so because on the assumption of “weak” plasticity the child achieves an adequate knowledge of language through an atypical developmental course. If so, then in what sense are these innate constraints crucial for acquisition?

Notice, that it does not matter whether the hypothesized acquisitional course for which innate constraints are crucial, involves linguistic postulates and thus is domain-specific or if it is dependent on particular cognitive substructures, as for example, Schlesinger’s theory of the origin of linguistic categories. “Weak” plasticity adversely affects the plausibility of both models since it means that the child can achieve mastery of language through a developmental route that is different from the hypothesized one.

There are three major classes of congenital pathologies for which the notion of plasticity is relevant.

1. First, consider deaf or blind children: If visual input is critical for language acquisition, if a brain that is deprived of visual input is different in relevant ways from a brain that does receive pictorial information, then there cannot be “strong” plasticity. The reasoning is similar in the case of deaf children. If the modality in which language is cast, vocal versus manual signing, critically affects language development, then there cannot be “strong” plasticity. If, on the other hand, as most research to date shows, being deprived of visual input or having recourse to manual signing instead of voice does not affect the developmental course, the claim of “strong” plasticity is strengthened. I submit that in view of current research in which the line of argument is that sign languages are structurally equivalent to spoken languages (e.g., Bellugi & Studdert-Kennedy, 1980; Lillo-Martin, 1992; Newport & Meier, 1985), it is doubtful whether in the case of deafness one wants to invoke plasticity. However, language learning that proceeds in the absence of visual input, conceivably does call for reorganization.

2. The second group of subjects are children who have suffered a physical insult to the brain. Most relevant to language acquisition are cases that result in major left-hemisphere lesions. Plasticity presupposes that the redundancy of brain tissues is such that if an area of the brain is unable to subserve the function normally assigned to it, other brain areas will take over. In the case of language, one has to assume that there is enough “free” brain areas of the kind that is potentially capable of developing language. A normal developmental course in such children supports “strong” plasticity.

If empirical findings favor “weak” plasticity, this may mean that a deficient brain, for which reorganization is required, is indeed functionally different from the normal. As mentioned earlier, “weak” plasticity will create serious difficulties for theories that presuppose that the ultimate achievement of language knowledge is crucially affected by innate constraints.

A further, intriguing question concerns reorganization. Assuming the brain sets limitations on possible reorganizations and therefore on possible functional outcomes, what might those be? How is such a reorganization related to the normal course of development? Finally, are there different ways of reorganization or does reorganization result in functional commonalities regardless of the nature of the original pathology?

3. A third class of congenital pathologies includes those that result in global, diffuse pathology (such as occurs in Down syndrome or in autism). Plasticity in these cases may assume different forms, including, at least as a logical possibility, a shift in language localization. These children may begin by following the normal course of acquisition. Yet, such “strong” plasticity may nevertheless stop short of the final achievements of normal children as seems to be the case with Down syndrome children (Fowler, 1989).

Alternatively, such children may show “weak” plasticity, that is, good command of language despite a deviant developmental course. It is also possible that both learning and ultimate achievements will be generally “depressed.”

What then is the relevance of studies of pathology to theories of acquisition? The reality of work in pathology has taught us that there are always many more possibilities than those outlined by any given theoretical model. Perhaps the way to proceed is to assume some version of a “double dissociation,” familiar from cognitive neuropsychology. The minimal methodological requirement is the following: In the absence of a generalized model of acquisition, specific empirical predictions in the context of normal acquisition should be considered. These very same things are examined in cases of pathology. For example, assume that there are two phenomena, A and B, and they present a typical developmental picture in normals. In this case, double dissociation predicts that there will be cases in which A will be deficient yet B will be intact, and other cases in which B will be deficient while A will remain intact.

So, although we can firmly assert the crucial role of cross-linguistic studies in a generalized model of language acquisition, the question whether pathology will prove critical in the same sense remains primarily an empirical one.

A number of general issues recur in this book. They all relate to the major theoretical debate between nativism and empiricism. Given the current state of our empirical knowledge, one may look on this division as expressing acts of faith from which follow research agendas (Schlesinger, chap. 4). Nativism presupposes innate constraints and mechanisms that guide language acquisition, while empiricism is committed to showing how things develop out of observables. Consider the nature of early categories: Empiricist approaches to language acquisition tend to view early categories as derived from preexisting cognitive/semantic or social interactive notions. However, semantics seems necessary for bootstrapping the formal linguistic system even in some otherwise strictly nativist approaches to acquisition (Pinker, 1984). Notice that whereas semantic, cognitive, or social categorization seem meaningful and relevant to the world around us, abstract linguistic categories are devoid of content and specific to language. Still, all categorization is necessarily dependent on formal systematization.

Another question concerns modularity (Fodor, 1983). Within language acquisition this term has been mostly used to refer to domain specificity and thus is more frequently argued for among nativists. However, modularity is by no means logically entailed by nativism. Domain specificity is ruled out by the empiricist approaches to acquisition, such as those expressed in this volume, although in this case too, one may envisage empiricist approaches to acquisition that will be domain specific, for example, learning based on distributional analyses (Wolff, 1988). The concluding chapter to this book discusses the empirical contributions of data from pathology to the modularity thesis.

While empiricism cannot take off without assuming the existence of certain innate constraints, both within language and in other relevant domains, nativism must allow for development in certain areas. In some cases this involves developmental mechanisms that another discipline will have to explain (i.e., maturation), but there is also linguistic learning, such as must occur for language-specific properties. The differences between the empiricist and the nativist agendas seem to lie in the amount of work that innate constraints are allowed to do, the readiness with which one resorts to such a mechanism and the kind of constraints they purport to be—“obscure” formal parameters or “palatable” cognitive ones.

Hyams (chap. 2) provides a rebuttal of the major criticism that has been voiced against the theory of Principles and Parameters as a theory of acquisition. In her view, research should aim at an account of language acquisition that will have explanatory power. This is achieved when children’s grammars are “possible” grammars, that is, intermediate stages en route to the mature grammar. In order to be “possible,” children’s grammars have to follow the principles of UG. Hyams responds to the charges that the data does not support instantaneous learning and that within UG there is no room for individual differences. She explains how partial learning may be accounted for and shows how principles of UG and core grammar in interaction with language-specific structures result in cross-linguistic differences.

Bloom (chap. 3) argues against the postulation of LAD as an intermediate level between grammar and cognition. He offers an account of the acquisition of the count/mass distinction in English, which assumes a direct mapping between the cognitive notion of individuals and the linguistic notion of count nouns. He further suggests that this notion accounts for facts relating to word learning. Bloom is a nativist who considers general cognitive constraints that map directly onto the linguistic system.

Schlesinger (chap. 4) sets the stage for the debate between empiricism and nativism. He views these as two competing research programs. For Schlesinger, empiricism is the only serious research program currently available. He introduces the process of semantic assimilation as a means of assuring a gradual expansion of semantic categories into corresponding syntactic categories. Clearly, this procedure does not presuppose modularity. He presents counter-arguments to some specific claims made by the theory of Principles and Parameters and concludes that there is no evidence in favor of nativism, nor are there conducive arguments against it.

Hoekstra (chap. 5) is concerned with the fact that child language lacks functional categories. He considers three types of explanations: (a) A parametric approach that assumes that the grammar of children is a “possible” grammar in the sense of Hyams; (b) the subgrammar approach, which is the assumption that at each given stage children have a partial knowledge of the adult grammar; (c) the approach that treats children’s grammar as a system by itself rather than as part of UG. Hoekstra offers an analysis of functional categories in Dutch, which stays within the options offered by the principles of UG.

Pizzuto and Casseli (chap. 6) present data from the development of inflections in Italian, which serve to argue against the major tenets of the theory of Principles and Parameters (Chomsky, 1986). In her view the major prediction of this model, namely, that there is rule learning, cannot be reconciled with the thrust of the empirical findings that demonstrate gradual development. Pizzuto views language development as taking place in a cognitive framework within which there is frequent concurring of distributional, pragmatic, semantic, morphophonological, as well as cognitive factors, which together are responsible for the pace and sequence of grammatical development. This is argued in detail in relation to the development of the morphological system in Italian.

Berman’s (chap. 7) views are in line with Pizzuto’s. She argues that development is affected by a “confluence of cues.” It is an interactive developmental approach assuming that development reflects morphological and syntactic complexity on the one hand, and the availability of rhetorical options in the language and typological centrality on the other. Berman discusses the development of Hebrew derivational and inflectional morphology, centering her argument specifically on the development of transitivity. She assumes a general developmental model that proceeds from unanalyzed forms to segregated small systems with rules and structures, to an integrated linguistic system. Thus, early phases will be similar across languages and later acquisitional stages will show more of language-specific differences.

Pye (chap. 8) discusses the variability that is found in the ways in which languages divide semantic domains. The example he studies in detail is the causative system in K’iche’. In this language, transitivity is marked morphologically and has an additional morphological paradigm for causatives. Pye finds that children learning K’iche’ follow a unique developmental course for causatives. The fact that they differ from English speakers is interpreted by Pye as evidence for the centrality of the language typology as opposed to the universal structure of the semantic field.

Rispoli (chap. 9) examines the ways in which children learn grammatical relations. Viewed from the perspective of Relational Grammar, his cross-linguistic data afford the conclusion that the child constructs the adult system of grammatical relations by piecing together local, discrete subsystems. The result is a mosaic of relationships that fall together in language-specific ways. This, then, is an approach that views grammatical structure as strongly linked to semantic or pragmatic functions.

Linguistic theory as a data-generating device is the starting point of Roeper and Seymour (chap. 10). The acquisitional problem is seen not as that of knowing which sentences are grammatical but rather ruling out impossible interpretations. In the authors’ view, detailed aspects of linguistic theory are relevant to the diagnosis of impairment. Children with deficits inform the general developmental theory, as well as provide i...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright
• Contents
• Preface
• 1. Introduction
• I: General Theoretical Issues
• II: Cross-Linguistic Perspectives
• III: Pathology
• Author Index
• Language Index
• Subject Index