Simplicity and complexity in child language and its explanation

syntax. Even at the earliest stages, there is syntactic complexity. Children’s early production may be grammatically conservative, constrained in production and operating with a restricted lexicon, but it still demonstrates abstraction, generative capacity, and principled behavior. These approaches can be summarized: 1. Regularities in grammar are an acquired from experience itself versus 2. Principles of grammar are innate, pre-existing and require only triggering exposure to constructions. The latter system is referred to as a Continuity Model because it does not project a role for maturation, although maturation within that model is possible. How does this connect to General Learning theory? Fodor (1975 and elsewhere) has argued there is no “learning” but rather “warranted fixed belief” where all of learning is highly constrained by a set of possible connections available to the mind. Thus the interepretation of emotion and gesture (like a universal smile) are built in. Even where substantial cultural variation exists---as in the interpretation of intonation--the variation is within a very small domain. Likewise for athletic learning, or for artistic learning, though repeated experience has a role, they are all innately constrained. Thus there is a question about whether General Learning Theory can exist anywhere. Its claim to some legitimacy in language, under the banner of “constructivist” approaches, leads to empirical claims that can be evaluated. Constructivist approaches predict 1) gradual emergence, 2) an absence of productivity, and 3) item-by-item acquisition. Generative approaches predict children’s production to evidence rule-governed behavior, and underlying abstract categories. Nevertheless under both approaches, grammar cannot emerge full-blown at once: lexical items must be acquired, and language-specific syntax as well. Both may require minimal repetition (some frequency) but the latter carries out recognition with respect to a representation and its logic, not frequency. For instance, the fact that a child hears thousands of articles (a,the) but does not initially use them, suggests that the child rejects frequency when it has no interpretation within a representation. The recognition of recursion, which we discuss below, is language specific but succeeds with extremely small amounts of data. These stand as initial challenges to a non-generative account. Nevertheless, it is not always easy to distinguish between the predictions of constructivist and generativist approaches, when applied to early syntax (Aguado-Orea 2004). At the one-word stage, as Pinker has commented, everyone’s theory works. Even at the two-word stage, however, strong biases emerge: while word-order varies dramatically in the child’s experience, heavy constraints emerge. Children will say “big truck” or “truck big” and “it big”, but they never say *”big it” as Bloom ( ) has shown. Without a sharp representation of sentence-boundaries---in the child’s raw experience---such things easily occur, “since your truck is big, it will work” (the kind of sentence returned by Google), and should under a non-linguistic learning theory, appear in child grammar. The challenge of comparing theories is compounded by the fact they actually pursue different goals: learning approaches are interested in the nature of development, and grammatical approaches are interested in the nature of the representations at different stages. Without doubt, the actual course of development is affected by myriad real-life influences which a larger theory of human growth needs to acknowledge. Children may learn “watch out!” as a lexical item more easily than “be careful” because the former will be linked to a sharp intonation and visually available danger, though both are short imperatives. Since our primary goal is not to pit two corners of a field against each other, but to motivate a discussion on children’s complexity, we keep the terms Simple syntax and Abstract syntax to describe these alternatives. We acknowledge that, at lower levels of linguistic organization, syntactic and lexicon-only (partly non-linguistic) explanations may compete in determining the acquisition path. Grammar as an explanation becomes inescapable when considering the more complex cases with interactions between sentence form and discourse. Any theory of non-grammatical generalization will generate too many false options, utterly unattested, like *big it to succeed in explaining the narrow grammatical representations actually chosen by the child and evident in databases. What does the innatist view claim?. First, the lexicon and lexical acquisition is crucial to all theories. Lexical learning consists first of isolating words. Children arrive at an inventory of words by segmentation of the phonetic stream, then linking these word-units to specific syntactic environments (i.e., subcategorization). This step already engages a grammatical representation. Then the child must may semantic inferences to both the lexical items and its “subcategorization”, the syntactic frames (particles, objects, complements) it is associated with if it is a verb 1 . The fact that so-called GAP verbs (general, all-purpose verbs like do, get, put, make) are among the first verbs learned show that items are not learned one by one in isolation---they may have no meaning without an object. The expression make toast and make friends require that make itself be abstracted from a single visible action. If the child depended upon situational consistency, with visual backup, such abstract words would be the last, not the first, learned. The second core claim of the abstract syntax position is that the product of lexical learning, by conceptual necessity, has to interface explicitly with a system capable of formal productivity. The goal is a system capable of semantic compositionality in specific domains, like subject-verb relations. Verb-object relations (make friends) are based on subcategorization which makes them like extended words, open to idioms, while the Subject-Verb relation is uniformly compositional: John sings 1 See (syntactic bootstrapping) (Gillete, Gleitman, Gleitman & Lederer , 1999; Gleitman Cassidy, Nappa, Papafragou & Truesswell, 2005) and Mary sings involves the same relation between John and sings and Mary and sings This principle of compositionality describes a fundamental property of human language, but it must be aimed and ordered in a specific manner. It is not the same as composing the arrangement of furniture in a living room, which involves notions of spatial composition that are special to vision. The notion of compositionality is crucial to the understanding of natural language as it allows us to reconcile the infinite and creative nature of syntax with the construction of possible meanings. In other words, an abstract syntax is required to articulate the semantic structure which produces freedom of reference. Thus if syntactic productivity and semantic composition are independent, they provide infinite communicative powers. Theories of learning by association have no mechanism to decouple specific experiences from lexical items or whole sentences. Thus roasting chicken, roasting beef and roasting your toes by the fire would not be easily dissociable if the specific visual and mechanical image of roasting beef were immutably associated with the word roast. A productive syntax, linked to semantic composition, allows this freedom of reference to emerge and depart from the overload of specifics that the initial learning environment carries with it. This may be natural, but it is not automatic and therefore any alternative theory must explain how it happens. While grammar is in many respects conservative (Snyder (2007)), we find not only spontaneous new combinations of words (“don’t giggle me”) but new kinds of syntax---not found in the input---which articulate the range of “possible grammars” available to humans. Departures from the target grammar are never beyond possible grammars, and obvious possibilities on an associative level, like *big it, simply do not occur and cannot be accounted for without assuming principles of grammar a restrictions. We will support this perspective 1) first with details from early grammar in Spanish 2) second a discussion of how Merge, which might seem broader than grammar, is subject to narrow linguistic restrictions and is still open to recursion, and 3) with a discussion of how children’s syntax leads to systematic semantic interpretation. 2. Conservativity and creativity: the case of Spanish negation Negation has hidden syntactic and semantic complexity. It is a logical operator that can take scope over a whole clause, or simply apply to a constituent within a clause. A sentence string is often many-ways ambiguous as to the scope of the operator, and its interpretation is sensitive to sentential stress. (1) María no comió manzanas ‘Maria did not eat apples.’ (2) a. ‘It is not the case that Maria ate apples.’ (scope over the whole clause) b. ‘It was not apples that Maria ate’ (scope over direct object) c. ‘It was not eating apples that Maria did. (scope over VP) This variation shows that negative statements cannot be simply mapped onto the worlds as: Negation+Situation. Meaning differences require negation to assign different scopes as the paraphrases reveal above.. In effect, the meaning of a sentence requires us to project two contrasting situations, defined by the scope of the operator. So, (2b) focuses the contrast on the object, matching for instance a situation in which María ate pears. Nonetheless, as all parents know, despite its abstractness, negation is used early and robustly by young children. Are scope differences present, or do children attach a negation to a sentence and then just guess which meaning might be meant? María (López-Ornat, Fernández, Gallo & Mariscal, 1994) reaches what parents call in Spanish la edad del no, the ‘no’ stage, at the age of 1;9. In that file, roughly one in seven words is no. However, the negative utterances she produces at that point are primarily of two kinds: holophrastic no and final no, where a phrase is followed by the sentential negation marker (XP + no). Shortly after this initial stage, sentence initial and sentence medial negation become productive, and negative concord appears shortly afterwards. Negation use expands into a variety of complex syntax and uses, beyond rejections into denial, property negation and even counterfactual sentences. By the age of four this child has acquired a full repertoire of negative sentences. (3) Earliest negation a. No, no .[% throwing herself on the ground] b. Pupa no. ‘Not a bubu.’ c. Nene sienta no. ‘The child is not sitting.’ d. Tista [triste] no. ‘Not sad’ (María,1;9) (4) Additional patterns become robust at 2;1 a. No la chupan las vacas. ‘It is not being sucked by the cows’ c. Este no es tuyo, e de mamá solo! ‘This is not yours, it is only Mommy’s’ (María, 2;1) (5) Negative concord a. Nada, caca ‘Nothing, poop.’ (María, 2;0) b. No sabo nada. ‘I don’t know anything.’ (María, 2;1) (6) Additional complexity: embedded negation, negative tags, negation in conditionals and counterfactuals a. Teresa no lo estudia porque ella me ha dicho a mi: yo no estudio nada de lo que me dice la señorita . ‘Teresa is not studying it because she told me “I am not studying anything of what the teacher tells me.” (Maria, 3;6) b. Esto no es plátano, a qué no ? ‘This is not a banana, I bet not.’ (Maria, 3;6) c. No, si me quitaran el lápiz no podía escribir. ‘No, if the would take away the pencil I would not be able to write.’ (María, 3;11) Relevant to our question is María’s seeming lack of productivity at the initial stage, in terms of syntactic frames associated with no. A quantitative comparison of her utterances with her parents at that stage shows that her preferred pattern is quite atypical in the adult input: the final negation pattern is the only productive complex use of no, but for her mother is the least common pattern. Table 1. Frequency of basic sentence patterns with negation.