4.2 Current approaches to the study of language acquisition
4.2.3 Empiricist approaches to the study of language acquisition Empiricist theories (table 4.1) attempt to explain language acquisition
without attributing to children abstract linguistic knowledge. Bates and MacWhin- ney (1989, 1987) propose a “Functionalism and Competition Model” (F&CM) of language acquisition, according with general “connectionist” modeling and with a “Language Making Capacity.”26A“usage based account” hypothesizes that language acquisition is based on item by item imitative learning (Tomasello 2000a, b).
4.2.3.1 Functionalism and Competition Model (F&CM)
The F&CM proposes “that Universal Grammar can ultimately be explained without recourse to a special ‘language organ’ that takes up where cognition leaves off ” (Bates and MacWhinney 1989, 7). It attempts to rectify a lack of emphasis on learning in the rationalist perspective. The source of knowl- edge is proposed to lie in the input, not in the mind. Discoveries are made “during processing of the structure inherent in the input” (Elman et al. 1996, 123). The mechanisms of acquisition lie in inductive learning. Language acquisition “is guided by form–function correlations” (Bates and MacWhinney 1989, 26). The relation between input data and the child mind/brain is direct and input-driven.
The approach is founded on an interpretation of linguisticfunctionalism: “the forms of natural languages are created, governed, constrained, acquired and used in the service of communicative functions” (Bates and MacWhinney 1989, 3), which attributes a causal and reinforcing role to pragmatic factors in linguistic competence. Unlike earlier empiricist approaches, the F&CM does not deny that innateness is a prerequisite for the acquisition of language, although the term
25Lust 1999; Boser, Santelmann, Barbier and Lust 1995; Santelmann, Berk and Lust 2000. Several intermediate proposals have been entertained, e.g., Borer and Rohrbacher’s 2002 “Full Compe- tence Hypothesis”.
26Slobin 1973, 1985; Elman et al. 1996 lay out the general perspective of this framework as “Rethink- ing Innateness.”
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is redefined; it now refers to “putative aspects of brain structure, cognition or behavior that are the product of interactions internal to the organism” (Elman et al. 1996, 23).27Symbolic rules, principles or constraints are replaced by phys- ical architecture and its function. Symbolic representation of the input data and computation over this representation are bypassed initially, and only emerge as a
“property of the network’s functioning” (Elman et al. 1996, 124).
Language acquisition is viewed not as a cognitive problem, but as “a perceptual- motor problem” (Bates and MacWhinney 1989, 31). Language development involves “a process of emergence” from connections (Elman et al. 1996, 359), not a cognitive construction based on cognitive computation over symbolic represen- tations; “something new seems to emerge from out of nowhere” (113) through a combination of biology and connectionism involving match and mismatch between inputs and outputs.
4.2.3.2 Connectionism
The term “connectionism” refers in general to a form of cognitive modeling wherein cognitive processing is represented in terms that can be imple- mented by a mechanical device, i.e., by a computer programmed to carry out the processes.28Current approaches to connectionism range widely in their techni- cal properties as well as in their essential nature. Some explicitly recognize a linguistic symbolic component wherein “structured mental representations and structure-sensitive processes” are recognized (e.g., Smolensky 1991, 201). In contrast, Elman et al. (1996) adopt a strong form which does not recognize a linguistic symbolic component.29
The essential methodological assumption is: if computational modeling can be accomplished for the learning of a specific behavior, then it is possible that this modeling reflects the actual cognitive process involved in human learning and knowledge. In one classic example, Rumelhart and McClelland (1986) showed that it is possible for a computer learning network using “Parallel Distributed Processing” (PDP) to model a U-shaped developmental curve with regard to the acquisition of English verbal morphology (chapter 11). The network did not assume linguistic units such as “word” or “word stem” or “rules.” Rather, “all that happens in learning is that the network compares its own version of the past tense form with the correct version provided by a ‘teacher,’ and adjusts the strengths of the connections and the thresholds so as to reduce the difference” (Prince and Pinker 1988, 195). In the machine’s learning curve, “not only did overregulariza- tion of the past tense occur, but the patterns were strikingly like those that occur in children’s speech” (Kolata 1987, 134). Rumelhart and McClelland conclude
27Elman et al. 1996 explicitly state “We are not empiricists” (357), presumably because they accept the necessity of some form of innateness in a comprehensive learning model.
28See Rumelhart and McClelland 1986, figure 7.3. MacWhinney 1989 views “connectionism” as a “way to formalize” the Functionalism and Competition Model (1989, 422). “Cue strength” is a “quintessentially connectionist notion” concerning “the weight on the connection beween two units” (Bates and MacWhinney 1989, 43).
29See Pinker and Prince 1988.
that “implicit knowledge of language may be stored in connections among simple processing units organized into networks” (1986, 195).
To date, this paradigm has not attempted to confront the full extent of gram- matical knowledge which is involved in language acquisition (chapter 2); nor has it attempted to confront the indirect relation of the child to the data which we reviewed in chapter 3. Most principled and systematic aspects of syntactic knowledge appear to be considered merely as “structural eccentricities” (Elman et al. 1996; Smith 1997). This paradigm has recently begun to extend to other areas of language knowledge, e.g., vocabulary and syntax acquisition (Plunkett 1996), although no precise hypotheses are presented yet for why “mice do not become men, and vice-versa” (Elman et al. 1996, 361).30
Further evaluation of any particular application of the model will necessitate evaluation of the specific manipulations providing the machine with programming for its operation.31It will also require empirical validation of the psychological phenomena chosen for study.
4.2.3.3 Language Making Capacity
Slobin proposes a “Language Making Capacity” (LMC) (1973, 1985).
Like Chomsky’s Language Faculty, the LMC contains universal principles (table 4.5). Unlike the principles of Chomsky’s Language Faculty, these are oper- ating principles (OP), i.e., principles specifically for working inductively on the physical acoustic stimulus of a specific language to which children are exposed.
The principles involve two types (i) Perceptual and Storage Filters and (ii) Pattern Makers (Slobin 1985, 1161). The early formulation of these operating principles in 1973 was generalized, specified and extended in 1985.
The formulation of an LMC considers that children must process specific lan- guage data in order to acquire a language, and takes a data-up approach. With a cross-linguistic approach, it attempts to provide “detailed examination of chil- dren’s verbal interaction with others . . . across individual children and languages”
in order to “begin to form hypotheses about the underlying capacities that may be responsible for language acquisition in general” (Slobin 1985, 1158). Accord- ingly, the LMC paradigm has provoked many studies of language acquisition across various languages and much description of the real time course of devel- opment in language acquisition. (See the Slobin 1985, 1992, 1997 collections.)
The OP propose that children are at first dependent on concrete, perceptually salient properties of the speech stream, presumably because this would aid their induction. Thus children are proposed to fail at first with abstract relations between underlying structures and surface strings, with order permutations, with empty
30The authors realize “we are probably going to have to work out a scenario involving constraints on architecture and timing” (Elman et al. 1996, 361).
31For example, Pinker and Prince 1988 argued that the original Rumelhart and McClelland results depended on the researcher changing the input to the computer in specific ways at specific times in order to result in the U-shaped developmental curve. They provided empirical evidence that in children’s natural environment, irregular verbs are always more frequent.
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Table 4.5 The Language Making Capacity (LMC) (Slobin 1973, 1985) TheLMCis “a set of procedures for the construction of language” (1985, 1159)
“Clearly LMC must begin life with some initial procedures for perceiving, storing and analyzing linguistic experience, and for making use of capacities and
accumulated knowledge for producing and interpreting utterances”
Two Types:
1. Perceptual and Storage Filters: “convert speech into stored data which the child will be able to use in constructing language” (1985, 1161)
2. Pattern Makers: “used to organize stored data into linguistic systems” (1985, 1161).
Operating Principles (1973) A. Pay attention to the ends of words
B. The phonological forms of words can be systematically modified C. Pay attention to the order of words and morphemes
D. Avoid interruption or rearrangement of linguistic units
E. Underlying semantic relations should be marked overtly and clearly F. Avoid exceptions
G. The use of grammatical markers should make semantic sense Supplemented and Developed in 1985
Perceptual and storage filters
OP (ATTENTION SOUND) Store any perceptually salient stretches of speech OP (STORAGE: FREQUENCY) Keep track of frequency of occurrence of every unit and pattern that you store
OP (ATTENTION): END OF UNIT.
OP (ATTENTION): STRESS
OP (ATTENTION): BEGINNING OF UNIT Pattern makers
Conceptual development provides starting points for grammatical marking (1985, 6).
Conceptual development determines order of emergence of grammatical forms (1985, 9).
Concepts are combined in grammatical morphemes according to semantic affinities.
Grammatical markers are placed according to principles of semantic relevance.
categories, with semantic synonymy or ambiguity, or with wherever “semantic relations” are not “marked overtly and clearly.” Semantic bootstrapping appears to be assumed.
Bates and MacWhinney (1989, 72) propose that “work on operating principles can feed directly into work on the Competition Model,” although this proposed relation is not spelled out. On the other hand, Slobin considers the growth of perceptual and information-processing capacities to be “operating in conjunction
with innate schemas of grammar” (1985, 5). The OP could then be viewed as supplemental to UG principles.
Several, if not all of the proposed OP must be relevant to language acquisition in some way. However, the developmental status of the OP in language acquisition as “stand-alone” principles is not clear. Most of the OP apply to some linguistic
“unit,” e.g., word or syllable, which is assumed to pre-exist. Thus they assume that children have solved the initial foundations for language acquisition, i.e., discovering the units in the continuous speech stream (chapter 3). This would suggest that the proposed OP have an intermediate status in the course of language acquisition.
The operating principles are proposed to exist “in their initial form . . . prior to the child’s experience with language” (Slobin 1985, 1160). The form of the OP themselves may develop over the course of language acquisition, presum- ably led by the development of grammatical knowledge of the language to be acquired. If so, the OP can be viewed as derivative of, or dependent on, grammat- ical knowledge. The OP must assume children’s prior knowledge regarding the language being acquired. The original OP (A) could not have wide productive applicability to languages which are not suffixing, e.g., Algonquian languages such as Cree or Blackfoot or Inuktitut, or isolating languages such as Chinese.
Similarly, “Universal (C3) must be limited to languages that rely heavily on word order to express semantics relations” (Slobin 1985, 1165, fn. 6). Grammatical markers in natural languages do not generally have a simple one-to-one rela- tion to semantic or syntactic factors (cf. chapter 11). OP (A) was “derived from a widespread crosslinguistic finding that post-verbal and post-nominal locative markers were acquired earlier than pre-verbal and pre-nominal locative markers, holding semantic content constant” (Slobin 1985, 1164), but “holding semantic content constant” proves to be elusive; semantic content is language-specific to a significant degree. (See Slobin 1985, fn. 5 for discussion.)
Further analyses of the relation between OP and UG principles will be necessary to evaluate the status of OP and the LMC in language acquisition.
4.2.3.4 Usage-based item by item imitative learning
Another attempt to provide an alternative to the rationalist paradigm of a Language Faculty is currently being developed by Tomasello (e.g., 2000a, b).32 Here, children at first “imitatively learn” specific “concrete linguistic expressions,” without the aid of abstract specifically linguistic principles; then they use general “cognitive and social-cognitive” skills to “gradually and in piecemeal fashion” begin to “categorize, schematize and creatively combine these individually learned expressions and structures” (Tomasello 2000a, 156).
32Tomasello debates a particular interpretation of the Chomsky paradigm; he assumes that it pro- poses that “children have full linguistic competence at birth and need only to learn to express this competence overtly in performance” (2000a, 160).
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In this view, early “grammars” are qualitatively distinct from those of the adult.33
Tomasello bases his proposal on certain observations of child language data and experimental studies intended to assess the nature of child language competence.
In early periods of language acquisition, natural speech samples do not usually demonstrate complete verbal paradigms, nor wide numbers of verbs used across verb paradigms, but commonly evidence utterances with individual verbs used in particular instances, e.g., with certain inflectional endings and not others.34This result suggests to Tomasello that children follow an “item based” approach and he formulates a “Verb Island Hypothesis” wherein “each of their verbs forms its own island of organization in an otherwise unorganized language system” with no abstract categories (Tomasello 2000a, 157). Experimental studies tested 2–3 year olds on whether they take novel verbs and change them, e.g., from intransitive as in (22a) to transitive as in (22b).
22. a. “The sock is tamming” (referring to a situation in which a bear was causing a sock to roll)
b. “He’s tamming the car” (e.g., when asked by the experimenter “What is the doggie doing” where the dog is causing the car to roll)
Tomasello and Brooks (1998) found that very few children produced a transitive sentence (like (22b)) with the novel verb in their experimental situation. This suggested to them that children lack abstract syntactic competence to generalize verbs to syntactic contexts they have not heard.
Since this model represents a relatively recent attempt to revive empiricist bases for language acquisition, its formulation is still at a preliminary stage. Before it can be fully evaluated as a viable and comprehensive alternative model, it must confront several issues: what are the specific “cognitive and social-cognitive”
mechanisms by which children are proposed to convert from an individual item to a generalized pattern? What form do children’s constructed “generalized patterns”
take and how do they relate to the actual linguistic structure of the constructions?
How do children determine “similarity” across constructions in order to know how to construct the proper generalization without linguistic analyses? What are the mechanisms by which children change from a non-grammatical to a grammatical form of knowledge? (In Tomasello’s proposal, this developmental change occurs at about three years.)
Attaining critical evidence on this proposal will depend on resolving certain methodological issues and issues of interpretation;35and on consulting the wide amounts of data now available on early periods of language acquisition which
33Compare an earlier proposal of this type in Braine 1971 and discussion in Brown 1973 on “pivot grammars”; Pine and Lieven 1997.
34Pizzuto and Caselli 1992 for Italian, Gathercole et al. 1999 for Spanish.
35Since the intransitive–transitive verb alternation is lexically specific and language-specific, a conservative learner, either child or adult, may not be expected to overgeneralize this alternation on any account.
appear to document continuous, abstract and systematic knowledge in early lan- guage acquisition.36
4.2.4 Empirical rationalists and rational empiricists