The faculty of language: what's special about it? ☆

TL;DR: The approach is sufficiently problematic that it cannot be used to support claims about evolution and related arguments that language is not an adaptation, namely that it is "perfect," non-redundant, unusable in any partial form, and badly designed for communication.

About: This article is published in Cognition.The article was published on 2005-03-01 and is currently open access. It has received 850 citations till now. The article focuses on the topics: Language acquisition & Biolinguistics.

Summary

Introduction

• And it is weakened by experiments suggesting that speech perception cannot be reduced to primate audition, that word learning cannot be reduced to fact learning, and that at least one gene involved in speech and language was evolutionarily selected in the human lineage but is not specific to recursion.
• The approach, however, is sufficiently problematic that it cannot be used to support claims about evolution.

1. The issue of what is special to language

• The most fundamental question in the study of the human language faculty is its place in the natural world: what kind of biological system it is, and how it relates to other systems in their own species and others.
• As with the first two questions, answers will seldom be dichotomous.
• But if represents a minor extension of capacities that existed in the ancestral primate lineage, it could be the result of a chance mutation that became fixed in the species through drift or other non-adaptive evolutionary mechanisms (Pinker & Bloom, 1990).
• In contrast, the authors suggest that FLN—the computational mechanism of recursion—is recently evolved and unique to their species” (p. 1573).
• The authors agree that it is conceptually useful to distinguish between the language faculty in its broad and narrow sense, to dissect the broad language faculty into sensorimotor, conceptual, and grammatical components, and to differentiate among the issues of shared versus unique abilities, gradual versus saltational evolution, and continuity versus change of evolutionary function.

2.1. Conceptual structure

• Let us begin with the messages that language expresses: mental representations in the form of conceptual structure (or, as HCF put it, outputs of the “conceptual–intentional system”).
• The authors add that many other conceptual systems, though not yet systematically studied in non-human primates, are conspicuous in human verbal interactions while being hard to discern in any aspect of primates’ naturalistic behavior.
• These too would be uniquely human aspects of the language faculty in its broad sense, but would be part of a system for non-linguistic reasoning about the world rather than for language itself.
• The notion of a “week” depends on counting time periods that cannot all be perceived at once; the authors doubt that such a concept could be developed or learned without the mediation of language.
• So here the authors more or less concur with HCF, while recognizing a more ramified situation.

2.2. Speech perception

• HCF implicitly reject Alvin Liberman’s hypothesis that “Speech is Special” (SiS).
• HCF cite this as evidence against SiS, together with three other findings: that certain animals can make auditory distinctions based on formant frequency, that tamarin monkeys can learn to discriminate the gross rhythms of different languages, and that monkeys can perceive formants in their own species’ vocalizations.
• Neuroimaging and brain-damage studies suggest that partly distinct sets of brain areas subserve speech and non-speech sounds (Hickok & Poeppel, 2000; Poeppel, 2001; Trout, 2001; Vouloumanos, Kiehl, Werker, & Liddle, 2001).
• Recent studies suggest that young infants, including neonates, prefer speech sounds to non-speech sounds with similar spectral and temporal properties.
• Nonetheless, if findings of similarities between humans and animals trained on human speech contrasts are taken as evidence that primate audition is a sufficient basis for human speech perception, findings of differences following such training must be taken as weakening such a conclusion.

2.3. Speech production

• Turning to the articulatory side of speech, HCF cite two arguments against evolutionary adaptation for language in the human lineage.
• The other species that evolved comparable talents, namely certain birds and porpoises, are not ancestral to humans, and must have evolved their talents independently of what took place in human evolution.
• To reconcile the recursion-only hypothesis with the fact that vocal learning and imitation are distinctively human (among primates), HCF refer to a “capacity for vocal imitation” and assign it to the “broad language faculty” which subsumes non-languagespecific abilities.
• HCF’s second argument against human adaptations for speech production is the discovery that the descended human larynx (which allows a large space of discriminable vowels, while compromising other functions) can be found in certain other mammalian species, where it may have evolved to exaggerate perceived size.
• But this suggestion, even if correct, does not speak to the issue of whether the human vocal tract was evolutionarily shaped to subserve human language.

2.4. Phonology

• Having the potential to articulate speech sounds—that is, having a vocal tract of the right shape and controllable in the right ways—is not the same as being able to produce the sounds of a language.
• Example a relative clause inside a relative clause (a book that was written by the novelist you met last night), which automatically confers the ability to do so ad libitum (e.g. a book [that was written by the novelist [you met on the night [that the authors decided to buy the boat [that you liked so much]]]]).
• The rhythmic properties of language and music may well be unique to humans: informal observations suggest that no other primate can easily be trained to move to an auditory beat, as in marching, dancing, tapping the feet, or clapping the hands (Brown, Merker, & Wallin, 2000, p. 12).
• But there are no syllables built out of the combination of two or more full syllables, which is the crucial case for true recursion.
• Whether or not these hypotheses about the adaptive function of phonology are correct, it is undeniable that phonology constitutes a distinct level of organization of all human languages.

2.5. Words

• Some words, such as hello, ouch, yes, and allakazam, do not combine with other words (other than trivially, as in direct quotes).
• They do so by suggesting that word learning is not specific to language, citing the hypothesis, which they attribute to Bloom (1999) and Markson and Bloom (1997) that “human children may use domain-general mechanisms to acquire and recall words.”.
• Presumably it is because they attributed common knowledge of a name (mep) to that speaker, even though they had never witnessed that speaker learning the name.
• Behrend and collaborators (Behrend, Scofield, & Kleinknecht, 2001; Scofield & Behrend, 2003), refining a phenomenon discovered by Markman (1989), showed that two-year-old children assign a novel word to an object they are unfamiliar with rather than to one they are familiar with (presumably a consequence of an avoidance of synonymy), but they show no such effect for novel facts.
• Moreover, a good portion of people’s knowledge of words (especially verbs and functional morphemes) consists of exactly the kind of information that is manipulated by recursive syntax, the component held to make up the narrow language faculty.

2.6. Syntax

• The authors finally turn to syntactic structure, the principles by which words and morphemes are concatenated into sentences.
• Most languages of the world are not as strict about word order as English, and often the operative principles of phrase order concern topic and focus, a fairly marginal issue in English grammar.
• Languages are full of devices like pronouns and articles, which help signal which information the speaker expects to be old or new to express temporal and logical relations; restrictive and appositive modification (as in relative clauses); and grammatical distinctions among questions, imperatives, statements, and other kinds of illocutionary force, signaled by phrase order, morphology, or intonation.
• This differs from the kind of analysis mandated by a grammar of recursively embedded phrases, namely [high–[high–[high–low]–low]–low].
• Languages, mathematical notation, the set of all palindromes, and an infinity of others), the fact that actual human languages are a minuscule and well-defined subset of recursive languages is unexplained.

2.7. Summary of evidence on the recursion-only hypothesis

• The state of the evidence for HCF’s hypothesis that only recursion is special to language is as follows: † Conceptual structure: HCF plausibly suggest that human conceptual structure partly overlaps with that of other primates and partly incorporates newly evolved capacities.
• HCF discuss two ways in which words are a distinctively human ability, possibly unique to their species.
• None of these impairments knock out or compromise recursion alone.
• Since speech is the main feature that differentiates the natural auditory environments of humans and of chimpanzees, the authors speculate that these evolutionary changes were in the service of enhanced perception of speech.
• As more genes with effects on speech and language are identified, sequenced, and compared across individuals and species, additional tests contrasting the language-asadaptation hypothesis with the recursion-only hypothesis will be available.

3. The minimalist program as a rationale for the recursion-only hypothesis

• Given the disparity between the recursion-only hypothesis and the facts of language, together with its disparity from Chomsky’s earlier commitment to complexity and from Chomsky’s current overall approach to the language faculty, the Minimalist Program (MP) (Chomsky, 1995, 2000a,b; Lasnik, 2002).
• The major difficulty with the Minimalist Program, as Chomsky (2000b, p. 124) himself admits, is that “All the phenomena of language appear to refute it.”.
• The general point is unexceptionable, but it offers few grounds for confidence that the particular theory under discussion is correct.
• † Language is an “optimal” or “perfect” mapping between sound and meaning, and in this perfection it is unlike other biological systems. †.

4.1. Language is badly designed for communication

• The question is whether particular components of the functioning of FLN are adaptations for language, specifically acted upon by natural selection—or, even more broadly, whether FLN evolved for reasons other than communication (1574).
• Though Chomsky denies the truism that language is “properly regarded as a system for communication,” he provides no compelling reasons to doubt it, nor does he explain what a communication system would have to look like for it to be more “usable” or less “dysfunctional” than human languages.
• For all the authors know, hands might be used more often in fidgeting than grasping, but that would not make fidgeting the biological function of the hand.
• This is not to deny that inner speech enhances thought (Jackendoff, 1996), and that this enhancement has been a major influence on the growth of civilization.
• The primary adaptation is communication, with enhanced thought as an additional benefit.

4.2. Language is “perfect”

• Next let us consider the conjecture, central to the Minimalist Program, that language, though dysfunctional for communication, is a “perfect” or “optimal” mapping between sound and meaning, such that its form is structurally inevitable given what it has to bridge.
• There is a progression of functionality, not a dichotomy between one system that is “perfect” and other systems that are “not usable at all.”.
• With regard to recovering the meaning of words and sentences, one can rxmxve thx vxwxls, rexove and still retain partial (and sometimes total) intelligibility (Miller, 1967).
• Chomsky occasionally has alluded to the alleged non-redundancy of lexical storage in memory: “Consider the way an item is represented in the lexicon, with no redundancy, including just what is not predictable by rule” (Chomsky, 2000b, p. 118).
• 17 There is a simpler resolution of the apparent incompatibility between biology and Minimalism, namely that Chomsky’s recent claims about language have it backwards.

4.3. The narrow faculty language faculty evolved for reasons other than language

• HCF speculate that recursion, which they identify as the defining characteristic of the narrow language faculty, may have “evolved for reasons other than language.”.
• Indeed, the only reason language needs to be recursive is because its function is to express recursive thoughts.
• First, its recursive products are temporally sequenced, unlike those of social cognition or visual decomposition.
• The argument that language is no better designed for communication than hair styles is belied by the enormously greater expressive power of language and the fact that this power is enabled by the grammatical machinery that makes language so unusual.

Frequently asked questions

Q1. What have the authors contributed in "The faculty of language: what’s special about it?" ?

The authors examine the question of which aspects of language are uniquely human and uniquely linguistic in light of recent suggestions by Hauser, Chomsky, and Fitch that the only such aspect is syntactic recursion, the rest of language being either specific to humans but not to language ( e. g. words and concepts ) or not specific to humans ( e. g. speech perception ). The recursion-only claim, the authors suggest, is motivated by Chomsky ’ s recent approach to syntax, the Minimalist Program, which de-emphasizes the same aspects of language. The approach, however, is sufficiently problematic that it can not be used to support claims about evolution. 2004. 08. 004 * the authors thank Stephen Anderson, Paul Bloom, Susan Carey, Andrew Carstairs-McCarthy, Matt Cartmill, Noam Chomsky, Barbara Citko, Peter Culicover, Dan Dennett, Tecumseh Fitch, Randy Gallistel, David Geary, Tim German, Henry Gleitman, Lila Gleitman, Adele Goldberg, Marc Hauser, Greg Hickok, David Kemmerer, Patricia Kuhl, Shalom Lappin, Philip Lieberman, Alec Marantz, Martin Nowak, Paul Postal, Robert Provine, Robert Remez, Ben Shenoy, Elizabeth Spelke, Lynn Stein, J. D. Trout, Athena Vouloumanos, and Cognition referees for helpful comments and discussion. And it is weakened by experiments suggesting that speech perception can not be reduced to primate audition, that word learning can not be reduced to fact learning, and that at least one gene involved in speech and language was evolutionarily selected in the human lineage but is not specific to recursion. 

Q2. What is the universal design feature of human language?

As noted as early as Hockett (1960), “duality of patterning”—the existence of two levels of rule-governed combinatorial structure, one combining meaningless sounds into morphemes, the other combining meaningful morphemes into words and phrases—is a universal design feature of human language. 

Q3. What is the fundamental question in the study of the human language faculty?

The most fundamental question in the study of the human language faculty is its place in the natural world: what kind of biological system it is, and how it relates to other systems in their own species and others. 

Q4. What is the position of Chomsky’s strongest critics?

the position that very little is special to language, and that the special bits are minor modifications of other cognitive processes, is one that Chomsky’s strongest critics have counterposed to his for years. 

Q5. What are the arguments against evolution for language in the human lineage?

Turning to the articulatory side of speech, HCF cite two arguments against evolutionary adaptation for language in the human lineage. 

Q6. What is the evidence for HCF’s hypothesis that only recursive languages are special?

mathematical notation, the set of all palindromes, and an infinity of others), the fact that actual human languages are a minuscule and well-defined subset of recursive languages is unexplained. 

Q7. What does the HCF claim is that word learning is not specific to language?

They do so by suggesting that word learning is not specific to language, citing the hypothesis, which they attribute to Bloom (1999) and Markson and Bloom (1997) that “human children may use domain-general mechanisms to acquire and recall words.” 

Q8. What is the recent comparison of the genomes of mice, chimpanzees?

A recent comparison of the genomes of mice, chimpanzees, and humans turned up a number of genes that are expressed in the development of the auditory system and that have undergone positive selection in the human lineage (Clark et al., 2003).