18.432, Review: Language Acquisition: Lightfoot (2006)

LINGUIST Network linguist at LINGUISTLIST.ORG
Thu Feb 8 07:27:34 UTC 2007


LINGUIST List: Vol-18-432. Thu Feb 08 2007. ISSN: 1068 - 4875.

Subject: 18.432, Review: Language Acquisition:  Lightfoot (2006)

Moderators: Anthony Aristar, Eastern Michigan U <aristar at linguistlist.org>
            Helen Aristar-Dry, Eastern Michigan U <hdry at linguistlist.org>
 
Reviews: Laura Welcher, Rosetta Project / Long Now Foundation  
         <reviews at linguistlist.org> 

Homepage: http://linguistlist.org/

The LINGUIST List is funded by Eastern Michigan University, Wayne
State University, and donations from subscribers and publishers.

Editor for this issue: Laura Welcher <laura at linguistlist.org>
================================================================  

This LINGUIST List issue is a review of a book published by one of our
supporting publishers, commissioned by our book review editorial staff. We
welcome discussion of this book review on the list, and particularly invite
the author(s) or editor(s) of this book to join in. To start a discussion of
this book, you can use the Discussion form on the LINGUIST List website. For
the subject of the discussion, specify "Book Review" and the issue number of
this review. If you are interested in reviewing a book for LINGUIST, look for
the most recent posting with the subject "Reviews: AVAILABLE FOR REVIEW", and
follow the instructions at the top of the message. You can also contact the
book review staff directly.


===========================Directory==============================  

1)
Date: 08-Feb-2007
From: Michael Arbib < arbib at usc.edu >
Subject: How New Languages Emerge 

	
-------------------------Message 1 ---------------------------------- 
Date: Thu, 08 Feb 2007 02:25:43
From: Michael Arbib < arbib at usc.edu >
Subject: How New Languages Emerge 
 


Announced at http://linguistlist.org/issues/17/17-1250.html 

AUTHOR: Lightfoot, David
TITLE: How New Languages Emerge
PUBLISHER: Cambridge University Press
YEAR: 2006

Michael A. Arbib, Computer Science, Neuroscience and USC Brain Project,
University of Southern California

David Lightfoot develops his thesis that new languages emerge because
children internalize new grammars from the flux of language use around
them. To do this, he offers two complementary accounts: one of language
acquisition, and the other of language change. Lightfoot has aimed the book
at the general reader, but perhaps a quarter of the material will be hard
going for readers not used to reading standard linguistic examples. Some
footnotes announce that certain portions of the book are recycled from 2
earlier volumes, ''How to set parameters: arguments from language change''
(1991) and ''The development of Language Acquisition'' (1999). I have not
gone back to make an explicit comparison with these volumes but these
footnotes did alert me to ask ''How much of this book reflects post-1990
scholarship?'' The answer seems to be that Lightfoot has kept abreast of the
literature on historical linguistics on the history of English and related
studies of Scandinavian, but has followed almost no literature on other
than the Romance and Germanic languages, save for Nicaraguan Sign Language.
Given that Lightfoot asserts that the new historical linguistics is
excitingly interdisciplinary, it is even more striking that his discussion
of language acquisition is devoid of almost any analysis of actual studies
of children acquiring language.

EVALUATION

Lightfoot reviews the valuable distinction between E-language and
I-language -- between the wild variety of utterances ''out there'' and the
knowledge of language inside the head of the individual speaker. The child
joins the language community by constructing an I-language that
approximates aspects of the ambient E-language. The key point for the
discussion of language change is that the E-language is sufficiently
heterogeneous and the child's sample sufficiently small that different
children may end up with different I-languages. As old speakers die and new
speakers arise, the set of I-languages of the community changes. Their
combined effect may preserve the E-language of the previous generation,
change it in minor ways, or start changes that may cumulatively yield a new
E-dialect or E-language. I agree with this general framework but it leaves
open (at least) two major questions:

Language Acquisition: What is the nature of an I-language and how is it
acquired by the individual? A sub-question is how much of the I-language is
acquired by the young child, and how much may an individual's I-language
change over the lifespan?
Language Change: Language may change because of innovations invented and
disseminated by young and older adults, or it may occur because young
language learners extract new patterns from the ambient fluctuations of
E-language to create a new population of I-languages. Is this an either/or
situation, or are both processes operative?

LANGUAGE ACQUISITION

On p.7, Lightfoot states that ''children are internally endowed with certain
information, what linguists call Universal Grammar (UG), and, when exposed
to primary linguistic data, they develop a grammar, a mature linguistic
capacity, a person's internal language or I-language. The essential
properties of the eventual system are prescribed internally and are present
from birth''. There is no mention here or elsewhere in the book that many
linguists disagree with this, and thus there is no occasion to review
actual child development data to test alternative hypotheses. Consider, for
example, the work of Jane Hill (reviewed by Arbib & Hill, 1984) on language
acquisition. Jane modeled data she had gathered from a 2-year old child by
a process in which the child interiorizes fragments of what it hears to
build what we would now call constructions, based on the child's current
concerns and interests. Over time some constructions merge with others,
some fall into disuse, some gain complexity, and the lexicon grows and is
categorized in tandem with the development of these constructions. Such
ideas are now well developed in the recent volume by Tomasello (2003). The
issue here is not which approach to language acquisition is correct but,
rather, the need for evaluation of alternative theories, addressing the
related data on children's development.

Implicitly, the phrase ''a grammar, a mature linguistic capacity, a person's
internal language or I-language'' seems to omit the person's lexicon from
the I-language, and Lightfoot explicitly excludes social conventions of
language use from the I-language. He seems to consider the grammar as a set
of abstract rules of syntax and phonology, though the latter receives
little consideration here.

Anyway, the first major unquestioned hypothesis of the book is what I will
refer to as the UG/LAD hypothesis - that there is an innate UG and that the
child acquires its I-language (i.e., its syntax) via a Language Acquisition
Device (LAD) which scans the ambient E-language to determine which settings
of the parameters of UG match the sentences the child hears. Lightfoot
offers the usual Poverty of the Stimulus argument but fails to note that
recent literature militates against this argument (e.g., Pullum & Scholz,
2002). Indeed, when Lightfoot provides a critique of one approach to
instantiating UG/LAD, his strategy -- while offered as a better approach to
UG/LAD -- may actually be more in keeping with approaches that dismiss
UG/LAD. Lightfoot argues convincingly that one approach to the UG/LAD
hypothesis -- setting parameters by scanning through the entire E-language
(Clark, 1992; Gibson & Wexler, 1994) -- must fail. The argument is based on
the logic of a combinatorial explosion, not an analysis of developmental
data. He then argues -- again, I think, convincingly -- that the child does
not attend to the full complexity of adult sentences but instead attends to
fragments. I also agree that the child will not process complex sentences
(at least at first -- Lightfoot is not explicit about the ''maturation
schedule'') but will focus on simple sentences in the search for structure.
Where Lightfoot and I differ is that he sees the process of ''scanning
fragments'' as a search for ''cues'', which are items from UG which can
structure the sentence fragments. The catch is that these cues are highly
theory-laden. For example, the child is asked to recognize an empty verb
slot, or recognize a V-DP structure. However, no account is given of how
the young child recognizes an empty slot, or knows a DP when he sees one.
In what way, then, do I see Lightfoot as suggesting how the problem of the
poverty of the stimulus might be addressed without recourse to UG/LAD? It
is because once one accepts that the child is not looking at the entire
E-language to switch in a complete grammar from those licensed by UG, but
instead is slowly building up a repertoire of ''generation strategies'' for
fragments of a simplified subset of the E-language, then the way is open to
test the hypothesis that an innate UG is unnecessary after all. Instead one
may posit that the child builds up a set constructions that gradually
extend its ability to use language both to get others to minister to its
needs and to engage in a broadening range of social interactions.

Lightfoot pays essentially no attention to data on language acquisition
save to note the 4 stages that Clahsen & Smolka (1986) describe in the
acquisition of German. No theory is offered of how the child activates
''cues'' from the observed E-language nor -- perhaps the most crucial point
-- how the child avoids activating cues that seem to match other parts of
the language input. The reader seriously concerned with understanding
language acquisition will find little of value in Lightfoot beyond the idea
that early acquisition is driven by attending to fragments of simple
sentences rather than matching parameters against a wider sample that
includes complex sentences.

The reader wishing to understand the state of the art in the UG/LAD
approach to first language acquisition and the subtleties that arise when
one then considers language acquisition should turn to Dalila Ayoun's
(2003) ''Parameter Setting in Language Acquisition''. Ayoun makes clear that
many problems bedevil this work. The most fundamental problem is that there
is no agreement on which principles and parameters (or cues) form UG, or
when two putatively innate features of language are governed by a single
parameter. Another problem is to what extent the parameters or cues must be
activated according to a maturation schedule, rather than as and when a
sentence is encountered with the appropriate structure. And then the issue
of second language acquisition raises all sorts of problems about whether a
child's brain can hold 2 settings of the same parameter and bind them to
use of the appropriate language. The reader may either find this a superb
reference for further work on the UG/LAD approach or (as I did, presumably
contrary to Ayoun's intentions) a strong indication that UG/LAD does not
solve the language acquisition problem. In either case, it is a valuable book.

As Ayoun acknowledges and Lightfoot does not, the key to work on language
acquisition is to analyze data on how children acquire language. Here a
useful compendium is Eve Clark's (2003) ''First Language Acquisition''.
Unlike Lightfoot's view of I-language as being restricted to syntax and
phonology, Clark integrates social and cognitive approaches to how the
children understands and produces sounds, words and sentences -- all within
the context of learning to use language to cooperate and achieve goals.

LANGUAGE CHANGE

Lightfoot's Chapter 2, ''Traditional Language Change'', which ''draws heavily
on chapter 2 of Lightfoot (1999)'', introduces the study of historical
linguistics by presenting two lines of study that culminated in the
nineteenth century -- the study of the Great Vowel Shift and related
aspects of sound change, and the charting of ''family tress'' for the
Indo-European languages. He emphasizes that this research, for all its
success, has shortcomings because the researchers lacked the critical
distinction between E-language and I-language. 

After introducing UG/LAD and his views on language acquisition, Lightfoot
then develops his child-centered theory of historical language change in
Chapters 5 and 6, ''New E-languages cuing new I-languages'' and ''The use and
variation of grammars.'' I earlier raised the question of whether languages
change because of innovations invented and disseminated by adults, or
because of the way young language learners extract new patterns from of
E-language or both. Lightfoot again has no time to mention or debate
alternative hypotheses:  He insists without question that children's
formation of new I-languages is the key to how languages change. There is
no discussion of alternative views and thus no marshaling of support for
''his'' view. However, Croft (2000) offers a very different view of language
change and even devotes Section 3.2 to a critique of ''The child-based
theory of language change'', including an explicit analysis of some of
Lightfoot's earlier work. Lightfoot does not mention this.
Lightfoot offers what I (as an outsider) feel to be an excellent summary of
material from the history of English (and some related material on changes
in Scandinavian language) but offers no related data on child language. His
method is to simply observe that a change occurs in the texts from date x
to date y and then state without evidence that change in children's
I-languages must have been the driving factor. However, he usually states
that changes in E-language (e.g., due to Viking invasions) must have
triggered the changes. He offers no evidence (but see below) that the
changes were not made first by adults accommodating to the novel language
flux, and that children's language acquisition played a secondary role. To
take a contemporary example: the rapid changes in cell phone technology are
driven in great part by the enthusiasm of teenagers for new devices and
services, but the new devices and services are usually created by
thirty-year-olds (more or less) with the consumers providing selective
pressure. In the same way, it seems to me strange to privilege the language
learning of infants over the effects of adult innovation in response to a
whole host of historical processes including language contact.

Let's consider one example (p.131-2): ''Bean (1983) examined nine sections
of the Anglo-Saxon Chronicle [and] counted four constructions that needed
to be analyzed with the verb remaining in its VP. She found 50% of such
verbs in the section [sic] until 755, 25% in 865-864, ..., [and] 22% in
1132-1140. ... The option of moving the verb to a higher position was
exercised increasingly over a period of several hundred years. This no more
reflects a change in grammars than if some speaker were shown to use a
greater number of passive and imperative sentences. ... Nonetheless ...
changes in E-language, representing changes in the use of grammars, if they
show a slight cumulative effect, might have the consequence of changing the
robustness of the expression of cues, leading to new grammars. This seems
to be what happened during Middle English.'' And that's the method -- gather
data showing historical change, then argue that I-languages might change as
a result, and then assert without discussion that the change in I-languages
explains the E-language change. In my opinion, Lightfoot could make a
better case for the importance of child language in language change if he
abandoned the UG/LAD theory that an I-language is just a new combination of
innate parameters or cues. A construction-based view would not only support
the emergence of true novelty, but would also allow the child to acquire
multiple constructions even though the generative grammarian might assign
them to different UG parameter settings and then have as part of her
I-language the ''probability settings'' for when to apply the constructions
in different settings (cf. Eve Clark's usage-based approach). One could
then see the changes analyzed by Bean (1983) as marking a continuous change
in I-languages.

Perhaps the most promising Chapter, Chapter 7 on ''The eruption of new
grammars'', discusses creoles and signed languages but, beyond discussing
the latest paper (Senghas et al., 2004) on Nicaraguan Sign Language shows
little sign of reworking beyond Lightfoot's earlier books (1991, 1999). The
discussion of creoles usefully stresses the interaction of substrate and
superstrate languages in the formation of a creole, as against a Bioprogram
Hypothesis or expression of ''unmarked'' parameters in UG. However, Lightfoot
again emphasizes the children's formation of I-languages without analyzing
what adult interactions formed the pidgin from which the creole emerged, or
citing historical studies of the circumstances under which the substrate or
superstrate language may more heavily influence the final grammar (see.
e.g., Holm 2000 for a review of relevant material). Nicaraguan Sign
Language is, of course, fascinating because the children who created the
language over the course of some 30 years had no extant sign languages to
creolize. One may thus conclude that the children's formation of
I-languages was crucial, with the I-languages of each cohort providing the
E-language for the innovations of the next cohort. Lightfoot also usefully
cites data showing ways in which a child exposed to ''broken'' samples of
E-language may end up with an I-language that allows him to produce a
better version of the E-language than his models could provide. However,
there is nothing here that proves that all children have an innate UG/LAD
for signed as well as spoken language, and that Nicaraguan Sign Language
was created by children accumulating enough E-language to allow the younger
children to set parameters (or cues) for which there was hitherto no
evidence. Indeed, Senghas (2003) found that changes in the grammar of
Nicaraguan Sign Language first appear among preadolescent signers, soon
spreading to subsequent, younger learners, but not to adults. I would thus
say that older children sought to find new ways to communicate; and that
when they succeeded the new pattern of signing caught on with others and so
formed the E-language, with formation of I-languages playing a secondary
role of partial regularization. Again, the problem with Lightfoot's book is
that he never spells out the alternatives, and thus never marshals the data
needed to support his hypotheses.

And so we come to the concluding chapter, ''A new historical linguistics''.
We saw that Chapter 2 introduced the nineteenth century study of the Great
Vowel Shift and the charting of ''family trees'' for the Indo-European
languages, and emphasized that the research has shortcomings because the
researchers lacked the critical distinction between E-language and
I-language. One might hope then that the book would finish on a triumphal
note, celebrating the new insights that have accrued from using the UG/LAD
hypothesis to ground a child-centered theory of historical language change.
Instead we find that the book is silent on how to move forward the study of
historical phonology. As for getting insight into the historical
relatedness of languages, Lightfoot only offers a counsel of despair
(p.173): ''It is impossible to know what a corresponding form could be in
syntax, hard to know how one could define a sentence of French that
corresponds to some sentence of English [sic] and hard to see how the
comparative method could have anything to work with.'' Lightfoot's closing
analysis (pp.181-183) of recent research seems to suggest that historical
linguistics be abandoned in favor of comparative linguistics: ''Longobardi
... has developed an approach to defining relatedness between systems by
quantifying the degree of correspondence among corresponding settings,
without invoking reconstructions of any kind of change.'' Such an analysis
has nothing to do with how children acquire language. Moreover,
Longobardi's analysis (e.g., 2003, 2005) focuses on parameters he has
analyzed for the syntax of noun phrases, so that languages which appear
close by this method may differ dramatically in parameters for others
aspects of language. I am prepared to believe that such analysis has a role
to play, but stress that this utility holds even if we view UG as a purely
descriptive framework seeking to display a set of variations in the
grammars of human languages and reject the view that UG is an innate
capacity that guides all the essential processes of language acquisition
and thus delimits the set of possible human languages.

In conclusion, Lightfoot's book offers theories of both language
acquisition and language change by assertion. With minor exceptions, he
does not acknowledge the existence of rival theories and thus offers no
discussion of data pro or con his own theories. As a result, the case that
his approach will bolster work on historical linguistics seems ill-supported.

REFERENCES

Arbib, M.A., and Hill, J.C., 1984, Schemas, Computation, and Language
Acquisition, Human Development 27:282-296.

Ayoun, D. (2003) Parameter Setting in Language Acquisition, London: Continuum.

Bean, M., 1983, The development of word order patterns in Old English,
London: Croom Helm.

Clahsen, H., & Smolka, K.-D., 1986, Psycholinguistic evidence and the
description of V2 in German, in Verb-second phenomena in Germanic languages
(H. Haider & M. Prinzhorn, Eds.), Dordrecht: Foris, pp.137-167.

Clark, E. (2003) First Language Acquisition, Cambridge: Cambridge
University Press.

Clark, R., 1992, The selection of syntactic knowledge, Language
Acquisition, 2:83-149.

Croft, W., 2000, Explaining Language Change: An Evolutionary Approach,
Harlow, England: Longman.

Gibson, E., & Wexler, K.,1994, Triggers, Linguistic Inquiry, 25:407-454.

Holm, J., 2000, An introduction to pidgins and creoles, Cambridge:
Cambridge University Press.

Lightfoot, D.W., 1991, How to set parameters: arguments from language
change, Cambridge, MA: MIT Press.

Lightfoot, D.W., 1999, The development of Language Acquisition, Oxford:
Blackwell.

Longobardi, Giuseppe. 2003. Methods in Parametric Linguistics and Cognitive
History. Linguistic Variation Yearbook 3, 2003, 101-138.

Longobardi, Giuseppe. 2005. A Minimalist Program for Parametric
Linguistics? In Organizing Grammar: Linguistic Studies for Henk van
Riemsdijk, ed. by Hans Broekhuis, Norbert Corver, Marinus Huybregts, Ursula
Kleinhenz, and Jan Koster. Berlin/New York: Mouton de Gruyter, 407-414.

Pullum, G.K., & Scholz, B.C., 2002, Empirical assessment of stimulus
poverty arguments, The Linguistic Review, 19:9-50.

Senghas, A, 2003, Intergenerational influence and ontogenetic development
in the emergence of spatial grammar in Nicaraguan Sign Language Cognitive
Development 18:511-531.

Senghas A, Kita S, Ozyurek A., 2004, Children creating core properties of
language: evidence from an emerging sign language in Nicaragua. Science.
305:1779-82.

Tomasello, M., 2003, Constructing a Language: A Usage-Based Theory of
Language Acquisition, Cambridge, MA: Harvard University Press. 

ABOUT THE REVIEWER


Michael Arbib is a University Professor at the University of Southern
California. Among his edited and co-edited books are The Algebraic Theory
of Machines, Languages, and Semigroups, (Academic Press, 1968), Neural
Models of Language Processes (Academic Press, 1982), The Handbook of Brain
Theory and Neural Networks,  (The MIT Press, 1995, 2003), Who Needs
Emotions: The Brain Meets the Robot, (Oxford University Press, 2005), and
>From Action to Language via the Mirror System, (Cambridge University Press,
2006). 




-----------------------------------------------------------
LINGUIST List: Vol-18-432	

	



More information about the LINGUIST mailing list