Individual differences in native language attainment: A review article1

This article reviews several recent studies suggesting that – contrary to a widespread belief – native speakers of the same language do not share the same mental grammar. The studies examined various aspects of linguistic knowledge, including inflectional morphology, passives, quantifiers, and more complex constructions with subordinate clauses. The findings suggest that in some cases, language learners attend to different cues in the input and end up with different grammars; in others, some speakers extract only fairly specific, ‘local’ generalizations which apply to particular subclasses of items while others acquire more abstract rules which apply ‘across the board’. At least some of these differences are education-related: more educated speakers appear to master more general rules, possibly as a result of more varied linguistic experience. 1 Earlier versions of this paper were presented at the Symposium on Cognition Applied: UsageBased Linguistics and Language Learning (University of Southern Denmark, Odense, August 2007) and the Conference on Cognitive and Functional Approaches to Changing Languages (Tartu, May 2008). 2 “... children in the same linguistic community all learn the same grammar.” (Crain and Lillo-Martin 1999: 9) “... children are exposed to different samples of utterances but converge on the same grammar.” (Seidenberg 1997: 1600) “Children of the same speech community reliably learn the same grammar.” (Nowak et al. 2001: 114) “The set of utterances to which any child acquiring a language is exposed is equally compatible with many distinct descriptions. And yet children converge to a remarkable degree on a common grammar, with agreement on indefinitely many sentences that are novel. Mainly for this reason, Chomsky proposed that the child brings prior biases to the task.” (Lidz and Williams in press: 1) As these quotations illustrate, many linguists believe that all learners attain more or less the same steady state at the end of the language acquisition process. While this view is most strongly associated with generativists, it is also widely accepted by linguists and cognitive scientists with other theoretical orientations (cf. the Seidenberg quote). It is, of course, well known that there are large individual differences in vocabulary size and knowledge of highly literary constructions. However, when it comes to basic grammar, all adult speakers of the same language are thought to share the same system: in fact, this claim is sometimes used as evidence for other, more controversial claims (e.g. the existence of an innate universal grammar, as in the