Children in a given linguistic environment all uniformly acquire their target language, but adult learners of L2 do not. UG accounts for children's uniform linguistic behavior, but it cannot serve a similar role in accounting for adult learners' linguistic behavior. I argue that Epstein etal.'s study does not answer the question of why L2 learners end up with nonuniform and imperfect linguistic competence in learning a second language.

If Epstein et al. are right that adult second language learners have full access to UG, then all of the following should be true: adults should be able to consciously transform their I-Language; adults should be able to transform pidgins into Creoles; adults should be as likely as children to restructure their grammars on the basis of “functional” pressure. All the foregoing are false, however, which seriously calls into question the correctness of their hypothesis.

Many people have argued that the evolution of the human language faculty cannot be explained by Darwinian natural selection. Chomsky and Gould have suggested that language may have evolved as the by-product of selection for other abilities or as a consequence of as-yet unknown laws of growth and form. Others have argued that a biological specialization for grammar is incompatible with every tenet of Darwinian theory – that it shows no genetic variation, could not exist in any intermediate forms, confers (...) no selective advantage, and would require more evolutionary time and genomic space than is available. We examine these arguments and show that they depend on inaccurate assumptions about biology or language or both. Evolutionary theory offers clear criteria for when a trait should be attributed to natural selection: complex design for some function, and the absence of alternative processes capable of explaining such complexity. Human language meets these criteria: Grammar is a complex mechanism tailored to the transmission of propositional structures through a serial interface. Autonomous and arbitrary grammatical phenomena have been offered as counterexamples to the position that language is an adaptation, but this reasoning is unsound: Communication protocols depend on arbitrary conventions that are adaptive as long as they are shared. Consequently, language acquisition in the child should systematically differ from language evolution in the species, and attempts to analogize them are misleading. Reviewing other arguments and data, we conclude that there is every reason to believe that a specialization for grammar evolved by a conventional neo-Darwinian process. (shrink)

Cognitive science typically postulates unconscious mental phenomena, computational or otherwise, to explain cognitive capacities. The mental phenomena in question are supposed to be inaccessible in principle to consciousness. I try to show that this is a mistake, because all unconscious intentionality must be accessible in principle to consciousness; we have no notion of intrinsic intentionality except in terms of its accessibility to consciousness. I call this claim the The argument for it proceeds in six steps. The essential point is that (...) intrinsic intentionality has aspectual shape: Our mental representations represent the world under specific aspects, and these aspectual features are essential to a mental state's being the state that it is. (shrink)

Talk of linguistic universals has given cognitive scientists the impression that languages are all built to a common pattern. In fact, there are vanishingly few universals of language in the direct sense that all languages exhibit them. Instead, diversity can be found at almost every level of linguistic organization. This fundamentally changes the object of enquiry from a cognitive science perspective. This target article summarizes decades of cross-linguistic work by typologists and descriptive linguists, showing just how few and unprofound the (...) universal characteristics of language are, once we honestly confront the diversity offered to us by the world's 6,000 to 8,000 languages. After surveying the various uses of “universal,” we illustrate the ways languages vary radically in sound, meaning, and syntactic organization, and then we examine in more detail the core grammatical machinery of recursion, constituency, and grammatical relations. Although there are significant recurrent patterns in organization, these are better explained as stable engineering solutions satisfying multiple design constraints, reflecting both cultural-historical factors and the constraints of human cognition.Linguistic diversity then becomes the crucial datum for cognitive science: we are the only species with a communication system that is fundamentally variable at all levels. Recognizing the true extent of structural diversity in human language opens up exciting new research directions for cognitive scientists, offering thousands of different natural experiments given by different languages, with new opportunities for dialogue with biological paradigms concerned with change and diversity, and confronting us with the extraordinary plasticity of the highest human skills. (shrink)

What, in essence, characterizes the mind? According to Searle, the potential to be conscious provides the only definitive criterion. Thus, conscious states are unquestionably "mental"; "shallow unconscious" states are also "mental" by virtue of their capacity to be conscious (at least in principle); but there are no "deep unconscious mental states" - i.e. those rules and procedures without access to consciousness, inferred by cognitive science to characterize the operations of the unconscious mind are not mental at all. Indeed, according to (...) Searle, they have no ontological status - they are simply ways of describing some interesting facets of purely physiological phenomena. (shrink)

Our results support the idea that adults have access to the principles and parameters of Universal Grammar (UG), contrary to Epstein et al.'s misrepresentation of our work as involvingpartial access toUG. For both LI and L2 acquisition, functional projections appear to develop in a gradual fashion, but in L2 acquisition there ispartial transferin that the lowest projection (VP) is transferred from the speaker's LI.

In our opinion, the discontinuity between extant human and nonhuman minds is much broader and deeper than most researchers admit. We are happy to report that Evans & Levinson's (E&L's) target article strongly corroborates our unpopular hypothesis, and that the comparative evidence, in turn, bolsters E&L's provocative argument. Both a Universal Grammar and the “mental continuity” between human and nonhuman minds turn out to be modern myths.

Epstein et al.'s theory of SLA is heavily dependent on assumptions about both the nature of the acquisition device and the grammar that it produces. This commentary briefly explores the consequences of an alternative set of assumptions, focusing on the possibility that the acquisition device does not include UG and that syntactic representations do not contain functional projections.

The most compelling evidence for Epstein et al.'s central thesis that adult second language acquisition is constrained by the innate cognitive structures that constrain native language acquisition would be evidence of poverty of the stimulus. Although there are studies that point to such evidence, Epstein et al.'s primary form of argumentation, targetlike performance by second-language acquiring adults, is much less convincing.

Our response takes advantage of the wide-ranging commentary to clarify some aspects of our original proposal and augment others. We argue against the generative critics of our coevolutionary program for the language sciences, defend the use of close-to-surface models as minimizing cross-linguistic data distortion, and stress the growing role of stochastic simulations in making generalized historical accounts testable. These methods lead the search for general principles away from idealized representations and towards selective processes. Putting cultural evolution central in understanding language (...) diversity makes learning fundamental in the cognition of language: increasingly powerful models of general learning, paired with channelled caregiver input, seem set to manage language acquisition without recourse to any innate “universal grammar.” Understanding why human language has no clear parallels in the animal world requires a cross-species perspective: crucial ingredients are vocal learning (for which there are clear non-primate parallels) and an intention-attributing cognitive infrastructure that provides a universal base for language evolution. We conclude by situating linguistic diversity within a broader trend towards understanding human cognition through the study of variation in, for example, human genetics, neurocognition, and psycholinguistic processing. (shrink)

This commentary addresses two pervasive misconceptions which emerge in Epstein et al.'s target article: (1) that study of second language acquisition (SLA) began in the mid-twentieth century; (2) that SLA has only recently become able to contribute to linguistic theory. There is abundant historical counterevidence; I argue that (1) and (2) obscure the legitimacy of Epstein et al.'s “full access” hypothesis.

The implications of Epstein et al.'s critical evaluation of much of the existing literature on L2-acquisition extends far beyond the domain they discuss. I argue that similar methodological clarification is urgently needed in analyses of the role of UG in L1-acquisition, as well as in discussions in such seemingly “distant” areas as the study of language change.

The confirmatory nature of the empirical evidence used to establish UG effects in L2 development is considered. Specific issues are also raised concerning the internal validity of Epstein et al.'s findings. It is concluded that the role of UG in adult L2 development will only be established when researchers better understand the interaction between the development of UG-constrained structural knowledge and the development of overall L2 proficiency.

This commentary focuses on whether the full set of categories is available to beginning L2 learners. After critiquing Epstein et al.'s experimental evidence for the presence of functional categories, I outline the results of an experiment involving English speakers learning Japanese as a second language that does indeed point toward the early presence of fuuctional categories.

While child language development theory must explain invariant “success,” foreign language learning theory must explain variation and lack of success. The fundamental difference hypothesis (FDH) outlines such a theory. Epstein et al. ignore the explanatory burden, mischaracterize the FDH, and underestimate the resources of human cognition. The field of second language acquisition is not divided into camps by views on “access” to UG.

Epstein et al. attribute second language learning to the forces of transfer and language universals. They show that transfer is minimally involved in certain types of learning and therefore conclude that universals are involved. However, they forget to consider the important role of learning in second language acquisition.