Chomsky N. - The Evolution of the Language Faculty (with W. Tecumseh Fitch & Marc D. Hauser), e-books, English, Chomsky ...
[ Pobierz całość w formacie PDF ]
Cognition 97 (2005) 179–210
Discussion
The evolution of the language faculty:
Clarifications and implications
W. Tecumseh Fitch
a,
*
, Marc D. Hauser
b
, Noam Chomsky
c
a
University of St Andrews, School of Psychology, St Andrews, KY16 9JP, Scotland, UK
b
Harvard University, Cambridge, MA, USA
c
Massachusetts Institute of Technology, Cambridge, MA, USA
Received 5 November 2004; accepted 15 February 2005
Abstract
In this response to Pinker and Jackendoff’s critique, we extend our previous framework for
discussion of language evolution, clarifying certain distinctions and elaborating on a number of
points. In the first half of the paper, we reiterate that profitable research into the biology and
evolution of language requires fractionation of “language” into component mechanisms and
interfaces, a non-trivial endeavor whose results are unlikely to map onto traditional disciplinary
boundaries. Our terminological distinction between FLN and FLB is intended to help clarify
misunderstandings and aid interdisciplinary rapprochement. By blurring this distinction, Pinker and
Jackendoff mischaracterize our hypothesis 3 which concerns only FLN, not “language” as a whole.
Many of their arguments and examples are thus irrelevant to this hypothesis. Their critique of the
minimalist program is for the most part equally irrelevant, because very few of the arguments in our
original paper were tied to this program; in an online appendix we detail the deep inaccuracies in
their characterization of this program. Concerning evolution, we believe that Pinker and
Jackendoff’s emphasis on the past adaptive history of the language faculty is misplaced. Such
questions are unlikely to be resolved empirically due to a lack of relevant data, and invite speculation
rather than research. Preoccupation with the issue has retarded progress in the field by diverting
research away from empirical questions, many of which can be addressed with comparative data.
Moreover, offering an adaptive hypothesis as an alternative to our hypothesis concerning
mechanisms is a logical error, as questions of function are independent of those concerning
mechanism. The second half of our paper consists of a detailed response to the specific data
discussed by Pinker and Jackendoff. Although many of their examples are irrelevant to our original
DOI of original article: 10.1016/j.cognition.2005.04.006
*
Corresponding author.
E-mail address: wsf@st-andrews.ac.uk (W.T. Fitch).
0022-2860/$ - see front matter
q
2005 Published by Elsevier B.V.
doi:10.1016/j.cognition.2005.02.005
180
Discussion / Cognition 97 (2005) 179–210
paper and arguments, we find several areas of substantive disagreement that could be resolved by
future empirical research. We conclude that progress in understanding the evolution of language will
require much more empirical research, grounded in modern comparative biology, more
interdisciplinary collaboration, and much less of the adaptive storytelling and phylogenetic
speculation that has traditionally characterized the field.
q
2005 Published by Elsevier B.V.
1. Introduction
In a recent paper, we (
Hauser, Chomsky, & Fitch, 2002
) (HCF hereafter) offered a
framework for research on language evolution, stressing the importance of an empirical,
comparative and interdisciplinary approach to this problem, and of distinguishing between
several different notions of “language” found in the literature on this subject. In their paper
“The Faculty of Language: What’s Special about it?” Steven Pinker and Ray Jackendoff
(PJ hereafter) present a critique of this paper. In our response, we begin by noting the many
areas of agreement between HCF and PJ, among them the need to fractionate language into
its component mechanisms, the need for an empirical approach to test hypotheses about
these mechanisms, the value of comparative data from diverse animal species for doing so,
and the need for collaborative, inter-disciplinary work in this endeavor. However, several
distinctions and hypotheses that formed the core of our original paper have been
misunderstood by PJ. We first clarify these core ideas before addressing PJ’s specific
criticisms concerning empirical evidence. Many of their criticisms are based on a
mischaracterization of the perspective we outlined; but several substantive areas of
disagreement are discussed. This section allows us to clarify certain issues that were left
open in HCF, or unmentioned due to space constraints.
1.1. Clarifying the FLB/FLN distinction
One main thrust of PJ’s critique results from their blurring the distinction we drew
between broad and narrow interpretations of the term “faculty of language.” Although PJ
endorse this distinction, many of their arguments appear to result directly from a failure to
make it themselves, or to perceive where we were making it. We thus start by clarifying
this distinction, and its importance.
It rapidly became clear in the conversations leading up to HCF that considerable
confusion has resulted from the use of “language” to mean different things. We realized
that positions that seemed absurd and incomprehensible, and chasms that seemed
unbridgeable, were rendered quite manageable once the misunderstandings were cleared
up. For many linguists, “language” delineates an abstract core of computational
operations, central to language and probably unique to humans. For many biologists
and psychologists, “language” has much more general and various meanings, roughly
captured by “the communication system used by human beings.” Neither of these
explananda are more correct or proper, but statements about one of them may be
completely inapplicable to the other. To this end, we denoted “language” in a broad sense,
including all of the many mechanisms involved in speech and language, regardless of their
Discussion / Cognition 97 (2005) 179–210
181
overlap with other cognitive domains or with other species, as the “faculty of language in
the broad sense” or FLB. This term is meant to be inclusive, describing all of the capacities
that support language independently of whether they are specific to language and uniquely
human. Second, given that language as a whole is unique to our species, it seems likely
that some subset of the mechanisms of FLB is both unique to humans, and to language
itself. We dubbed this subset of mechanisms the faculty of language in the narrow sense
(FLN). Although these mechanisms have traditionally been the focus of considerable
discussion and debate, they are neither the only, nor necessarily the most, interesting
problems for biolinguistic research. The contents of FLN are to be empirically determined,
and could possibly be empty, if empirical findings showed that none of the mechanisms
involved are uniquely human or unique to language, and that only the way they are
integrated is specific to human language. The distinction itself is intended as a
terminological aid to interdisciplinary discussion and rapprochement, and obviously does
not constitute a testable hypothesis.
We believe that a long history of unproductive debate about language evolution has
resulted from a failure to keep this distinction clear, and that PJ, while agreeing with its
importance in principle, have not made it in practice. Only this can explain their
disagreement with the hypothesis they attribute to HCF at the culmination of their
introduction: “that recursion is the only aspect of language that is special to it, that it
evolved for functions other than language, and that this nullifies ‘the argument from
design’ that sees language as an adaptation”. In any interpretation that equates the last
“language” in this sentence with FLB, we not only disagree with this hypothesis (which is
not our own), but reject it as extremely implausible. Our focus on the mechanism of
recursion in HCF was intended as a plausible, testable hypothesis about a core component
of FLB, and likely FLN, not a blanket statement about “language as adaptation.” Here, we
hope to clarify any possible misunderstanding by exploring these issues in greater detail.
As we argued in HCF, treating “language“ as a monolithic whole both confuses
discussions of its evolution and blocks the consideration of useful sources of comparative
data. A more productive approach begins by unpacking FLB into its myriad component
mechanisms. These components include both peripheral mechanisms necessary for the
externalization of language, and core linguistic computational/cognitive mechanisms. The
proper fractionation of FLB into its components is obviously not trivial or given, and it
would be na¨ve to suppose that the biologically appropriate fractionation will precisely
mirror traditional disciplinary subdivisions within linguistics (phonetics, phonology,
syntax, semantics, etc.). For example, “phonetics” is traditionally concerned with the
sounds of spoken language, while “phonology” concerns more abstract questions
involving the mapping between sounds and linguistic structures. Though distinct, both
components of language presumably tap some of the same mechanisms. The “phon-” root
of both terms reveals their original preoccupation with sound, but language can also be
externalized through the visual and manual modality, as in signed languages, raising tricky
questions about the precise borders of the sensory-motor component of language. While it
would be a mistake to exclude visual/motor mechanisms from FLB, it is not a core
component for the vast majority of humans. This is not an issue we attempted to answer in
HCF, nor will we do so here. We raise it simply to illustrate the complexity of the issues
raised when one attempts to properly fractionate FLB.
182
Discussion / Cognition 97 (2005) 179–210
In HCF, we offered one potential cut through FLB, explicitly distinguishing the
sensory-motor (SM: phonetics/phonology) and conceptual-intentional (CI: semantics/
pragmatics) systems from the computational components of language that have been the
traditional focus of study in modern linguistics, including syntax, morphology, a
phonological component that interacts with SM systems, and a formal semantic
component that interacts with the CI system. We make no claims that this is the only
correct way to fractionate FLB, explicitly leaving room for other components (see Figure 1
in HCF). “We make no attempt to be comprehensive in our coverage of relevant or
interesting topics and problems” (p. 1570). However, contrary to PJ’s suggestion, our
framework does not exclude the many important issues that arise in phonology,
morphology, or the lexicon. Questions concerning how internal computations relate signal
and meaning are explicitly raised in the initial theoretical discussion (p. 1571), and must
be, by definition, part of an adequate theory of language.
Something about the faculty of language must be unique in order to explain the
differences between humans and other animals—if only the particular combination of
mechanisms in FLB. We thus made the further, and independent, terminological proposal
to denote that subset of FLB that is both specific to language and to humans as FLN. To
repeat a central point in our paper: FLN is composed of those components of the overall
faculty of language (FLB) that are both unique to humans and unique to or clearly
specialized for language. The contents of FLN are to be empirically determined. Possible
outcomes of this empirical endeavor include that ALL components of FLB are shared
either with other species, or with other non-linguistic cognitive domains in humans, and
only their combination and organization are unique to humans and language.
Alternatively, FLN may turn out to include a very rich set of interconnected mechanisms,
as assumed in many earlier versions of generative grammar. The only “claims” we make
regarding FLN are that (1) in order to avoid confusion, it is important to distinguish it from
FLB, and (2) comparative data are necessary, for obvious logical reasons, to decide upon
its contents. An equally obvious point is that research on non-linguistic cognitive domains
(number, navigation, social intelligence, music, and others) is fundamental to the proper
eventual delineation of FLN.
PJ’s central complaint with HCF lies with our further hypothesis—stated clearly as
such in the paper—that only a relatively compact, but powerful, component of the
computational component of language falls into the FLN subset of FLB (Hypothesis 3 of
HCF). “We propose in this hypothesis that FLN comprises only the core computational
mechanisms of recursion as they appear in narrow syntax and the mapping to the
interfaces.” (p. 1573). The term “FLN” thus served dual duties in HCF. To be precise, we
suggest that a significant piece of the linguistic machinery entails recursive operations, and
that these recursive operations must interface with SM and CI (and thus include aspects of
phonology, formal semantics and the lexicon insofar as they satisfy the uniqueness
condition of FLN, as defined). These mappings themselves could be complex (though we
do not know) because of conditions imposed by the interfaces. But our hypothesis focuses
on a known property of human language that provides its most powerful and unusual
signature: discrete infinity. We offered this hypothesis as a starting point for discussion and
research, “restricting attention to FLN as just defined but leaving the possibility of a more
inclusive definition open to further empirical research” (p. 1571). We do not define FLN as
Discussion / Cognition 97 (2005) 179–210
183
recursion by theoretical fiat (note, we say “a key component”), which would contradict the
aims of our paper, but offer this as a plausible, falsifiable hypothesis worthy of empirical
exploration. We hypothesize that “at a minimum, then, FLN includes the capacity of
recursion”, because this is what virtually all modern approaches to language (including
those endorsed by PJ) have agreed upon, at a minimum. Whatever else might be necessary
for human language, the mechanisms underlying discrete infinity are a critical capability
of FLB, and quite plausibly of FLN.
1.2. Biolinguistics and the Minimalist Program
PJ give a long and detailed critique of the Minimalist Program (MP), based on their
interpretation of how the minimalist program informed our “overall vision of what
language is like.” In fact, partly for reasons of space, HCF barely discussed MP. The
framework advanced in HCF for the study of language evolution does not rise or fall with
the fate of the minimalist program. Indeed, most of our points (e.g. the FLN/FLB
distinction, the value of an empirical, hypothesis-testing approach, the importance of
comparative data, etc.) apply equally to any of the various flavors of modern generative
grammar. Like HCF, our discussion here will be largely non-committal as regards the
virtues and faults of the various flavors of generative grammar currently available. The
only assumption made in HCF, and here, about syntactic theory is the uncontroversial one
that, minimally, it should have a place for recursion. We think researchers in fields outside
linguistics should adopt a wait-and-see attitude as these intradisciplinary issues are sorted
out. It is certainly not the case that our framework is based on a covert “presumption that
the Minimalist Program is ultimately going to be vindicated,” and we are quite puzzled by
PJ’s assertion to this effect.
PJ see minimalism as providing “a rationale” and “motivation” for our hypothesis 3—
the only obvious justification for their long and detailed critique of minimalism. This
speculation is incorrect. A primary motivation for writing HCF was our recognition of
some pervasive confusion that have led to persistent and unnecessary misunderstandings
among researchers interested in the biology and evolution of language. Such
misunderstanding has polarized debate unnecessarily, has helped to fuel dogmatic and
even hostile stances, and has generally acted to block progress in this field, including
especially the severing of possible collaborative projects between linguists, psychologists
and biologists. It has contributed to a situation in which animal researchers interested in
language almost automatically consider themselves anti-linguist, or anti-generative, while
some linguists feel justified in being anti-cognitive or anti-evolutionary. The FLN/FLB
distinction, we hoped, would help the field to see that there is no incompatibility between
the hypotheses that FLB is an adaptation that shares much with animals, and that the
mechanism(s) underlying FLN might be quite unique. We further realized that earlier
statements that had been interpreted as anti-evolutionary were in fact compatible with
contemporary (and perfectly orthodox) neo-Darwinian theory. This realization, not a
covert acceptance of minimalist precepts, was the primary motivation for writing HCF,
and phrasing our hypotheses as we did.
PJ’s comments about MP are thus mostly irrelevant to most of the topics of HCF, and of
the current paper, and due to space constraints we are unable to discuss them fully here.
[ Pobierz całość w formacie PDF ]