The language/genes metaphor (part 4)

Part IV: The basic building blocks of linguistic replication?

As I mentioned in the last post, I’m convinced that a language/phenotype analogy is more appropriate than a language/genes analogy. However, here’s a second piece of devil’s advocacy because I still believe a case can be made for the latter metaphor.

The language/genes metaphor is appropriate only if we assume that languages are the auditory manifestations of underlying linguistic structures, and that these structures replicate in the mind every time an individual learns a language, either as a first or second language. Entertaining this possibility means accepting Chomsky’s universal grammar hypothesis and his principles and parameters approach.

Does Chomsky’s approach provide some kind of mechanism whereby we can reduce linguistic structures to a few basic parts, the way we can reduce DNA and its replication to nucleotide bases and enzymes?

Yes, I think so. Phrase structure theory and X’ theory provide a framework for analyzing all human languages according to a few basic building blocks: phrases, phrase heads, complements, and specifiers. This is the “DNA” of language.


We don’t need to go into detail about this chart. Basically, all languages are built from phrase heads (X), which project to a phrase-bar (X’), which project to a phrase (XP). Phrase heads can optionally project a complement, and phrases can optionally project specifiers.

languageDNAFour phrase heads map onto—more or less—the grammatical categories we learn in school: verbs, nouns, prepositions, adverbs and adjectives (both categorized as AP). The other phrase heads are less well known. Tense phrases (aka Inflection Phrases) are an abstract category that allows verbs to inflect for tense and person. Complement phrases are projected from embedded clauses: words such as that or because are complementizers. And determiner phrases project from what we commonly call articles: the, a, an in English.

All human languages are built from these categories. All human languages can be analyzed according to the same basic rules of phrase projection. The difference between languages is the difference between various “parameter settings” for these phrases and projections, among other aspects of language structure that I haven’t talked about here.

One of the most salient cross-linguistic differences is, of course, word order. However, according to phrase structure and X’ theory, this difference is simply a matter of re-configuring or re-arranging the structural projections:

The structure of English word order (Subject - Verb - Object)

The structure of English word order
(Subject – Verb – Object)

The structure of Malagasy word order (Verb - Object - Subject)

The structure of Malagasy word order
(Verb – Object – Subject)

The structure of Japanese word order (Subject - Object - Verb)

The structure of Japanese word order
(Subject – Object – Verb)

So, for example, the difference between English and Japanese is simply the difference between an X’ that projects to X first and complement second (English) and an X’ that projects to complement first and X second (Japanese). In other words, English is a head-initial language and Japanese is a head-final language.


In a Chomskyan framework, there are basic building blocks of linguistic structures, and the differences between languages can be described as differences in the configuration and specification of these structures. Sounds roughly comparable to DNA in my opinion, but then, I’m not a geneticist . . .

(Note: the phrase table and the examples in this post are taken from the helpful notes of Dr. John Nissenbaum.)

The language/genes metaphor (part 3)

Part III: Do linguistic structures replicate?

On the Phylogenetic Networks blog, David Morrison has posted an excellent essay regarding the (as he sees it) false analogy between languages and genes. He suggests that a more apt metaphor would be that of languages/phenotypes. He was kind enough to send me an early draft of the post. Reading it was precisely what inspired me to write a few posts of my own on this subject.

Re-reading the essay, I find myself agreeing with its point once again. If we want to find a connection between linguistic and biological evolution, we should probably take a morphological, developmental, typographic approach—in short, a phenotypic approach. Phenotypes are the observable traits of an organism, the expressions of genotypes (or, more accurately, the expressions of genotypes and environmental pressures). So, phenotypes clearly offer a more grounded and potentially productive linguistic analogy than genotypes because a language is a composite of observable traits—from the phonetic level to the semantic level. A language/genes metaphor is askew; it confuses the replicators of hereditary information with the observable expression of that information.

If found to be productive, will the language/phenotype metaphor be as suggestive as the language/genes metaphor in the debate over language origins? I’m not sure. I’m inclined to say yes—pointing still toward an essentially biological view of language—because a productive language/phenotype analogy would also suggest that languages evolve in a way comparable to physical structures. But I’ll leave that question aside for now. In this post (and perhaps the next one), I still want to play devil’s advocate and entertain the possibility of a productive language/genes metaphor.

Clearly, the only way to do this is by assuming the veracity of Chomsky’s universal grammar (UG) and his principles and parameters approach. Assuming the other major linguistic theory—Halliday’s systemic functional grammar—the metaphor doesn’t work at all. It is not too misleading, however, in a Chomskyan framework, to view the phonology, morphology, and syntax of a language in a ‘genetic’ way because this framework assumes that languages are built on underlying structures that could be said to replicate themselves, in that these structures are expressed and understood by humans as language. One can view the relationship, without stretching things too much, as a two-tiered organization:


The language/structure distinction, in generative linguistics, is not as clear or even as important as the phenotype/genotype distinction in biology. But, again, we assume that languages are made possible by their underlying structures, and so it’s not entirely unfair to differentiate them for purposes of exploring this metaphor.

Do linguistic structures replicate themselves? In a sense, yes. In both first and second language acquisition research, evidence suggests that syntactic structures develop gradually. (We typically speak of grammars being ‘acquired,’ but the word denotes a structural development in the mind.) Of course, the development doesn’t begin with anything like sexual (2 parents to offspring) or even asexual (1 parent to offspring) reproduction. During first language acquisition, linguistic structures develop in the mind of a child over the course of about 2-5 years, and we might say the ‘parents’ of this linguistic development are anyone and everyone who communicates linguistically with the child, anyone who passes on structural linguistic information in the form of verbal interaction.

Take the following examples. (Examples come from Hawkins’ Second Language Syntax and Clark’s First Language Acquisition.) The first comes from an interaction between a 2 year old and his mother; the second comes from a second-language learner of English.

languagedevelop1Regardless of language, children and adults first develop lexical categories—nouns, verbs, and adjectives. In (1), the child is acquiring the lexeme mouse and is in the beginning stages of acquiring its plural form, mice. In (2), the adult has acquired basic English negation. At these early stages of development, the language has not “replicated” itself completely. The structures underlying them are unspecified.

languagedevelop2Only with time do the structures become specified: as more information is developed in the new speaker’s mind, the structures become more robust and slowly begin to replicate the fully functional language. For example, compare (2a) with (3) below, She isn’t old. (3) represents a fully developed—a fully specified— inflectional structure. The speaker is no longer working with a NegP and just attaching lexical items to it, as in (2a), She no old; instead, he has developed the category Tense, in conjunction with the ability to inflect and transform verbs. In short, the difference between (2a) and (3) is the difference between a language in the process of replication and a language that has been fully replicated in a speaker’s mind.

languagedevelop4The lexicon of a language contains its lexical categories, individual words with specific conceptual content. Lexicons vary from language to language—dog, der Hund, el perro. Lexical items are often the first things to develop during first or second language acquisition. The lexicon interacts with the language’s morphology to create richer semantic meaning—add –s to pluralize in English, add –en to pluralize in German; add ed to make an English verb past tense. Morphology develops gradually along with a language’s syntax, which connects all these pieces together to form coherent utterances, i.e., sentences.

A lot of information resides in any language; it is acquired piece by piece, starting with simple words and ending with fully formed syntax. The information resides in the minds of advanced speakers, and is transferred to new speakers through verbal interaction. Every time you speak with a child or non-native speaker, you are, in a sense, pollenating their mind with linguistic information which will eventually develop into a fully structured and specified language.

If languages do replicate in a way broadly similar to genes, then we would expect linguistic structures, like genes, to have some kind of uniform replication process. And, in many instances, we do find that linguistic structures replicate, or develop, along similar lines across different languages. (Obviously, most studies of language acquisition have been carried out with the world’s major Romance, Germanic, and Sino languages, so we don’t have anything like a complete picture of how all the world’s languages develop, but the evidence we do have suggests an organized process.)

For example, as discussed in Hawkins, several studies have shown that English verb phrases and noun phrases develop in a similar fashion across speakers, starting with bare VPs and NPs (unspecified lexical categories that simply attach to other lexical categories), moving through comparable levels of specification (e.g., the subsequent acquisition of definite article the and copula be, both of which are the ‘least specified’ specifications*), and ending with third-person singular –s and possessive –‘s.

languagedevelop5*The and copula be are not highly specified because both select for just about anything they want. The can select a singular noun (the girl) or a plural noun (the girls) regardless of the noun’s initial phoneme; in contrast, a can only select a singular noun that begins with a vowel, so the develops before a. Likewise, copula be selects for a noun (is the man), an adjective (is happy), or a preposition (is under the table); in contrast, auxiliary be only selects for a verb ending in –ing (is running), so copula be develops before auxiliary be.

More in the next post . . . I’ll end by noting that I’m only partially convinced by my own argument here about the replication of linguistic structures. As I said at the beginning, I’m more convinced that a language/phenotype analogy is more appropriate.

The language/genes metaphor (part 2)

Part II: Metaphors, and why this one is interesting

In the last post, I used an example from Jeanne Fahnestock’s Rhetorical Figures in Science to show what productive figuration looks like. Specifically, I discussed the figure incrementum and how it has provided a conceptual framework for research in evolutionary theory and astronomy.

When working with a metaphor, we want the same generative potential. We should expect the metaphor to provide a conceptual framework that allows researchers to look at something in a new way, to ask new questions, or to make new predictions. In every conceptual metaphor, there is a target domain and a source domain. The target is the object to which attributes are ascribed; the source is the object from which attributes are borrowed. In the language/genes metaphor, genes are the source, and linguistic structures are the target.

We shouldn’t expect every attribute of the source to mirror every attribute of the target at every step and in every way imaginable—we’re not talking about 1:1 correspondence here. Rather, a productive metaphor should allow us to see some attribute of the target in some way that was hitherto hidden before the comparison to the source was made. A metaphor, guided by the attributes of the source domain, selects and highlights certain features of the target domain (while, of course, deflecting other, perhaps more defining features—no metaphor is free. We’ll return to this epistemological danger later on.)

So. Genes and linguistic structures. I’m interested in this comparison because I’m interested in the origins and evolution of language. One of the great questions in science is whether language evolved from gesture and vocalization—becoming gradually more complex through increased socialization, mental awareness, and IQ—or whether language arose relatively quickly in a specific population, the result of a mutation or, more likely, a host of mutations.

I have to admit that a good prima facie case can be made for the latter view; this is the view held by Chomsky and most American linguists. Language, after all, operates on the basis of complex structures and lightning-fast computations, traits which make comparisons to animal vocalizations seem quaint (birds and chimps don’t inflect for case or subordinate clauses). We don’t see a ‘continuum of language’ in nature. Human language is only human language once it’s human language, regardless of what you’ve heard about bird and whale songs from the kumbaya types who chant parochial clichés about “similarities between humans and animals that make people feel uneasy.

However, even if we admit that language is a peculiarly human ability, there’s no necessary reason to assume that it is based on polygenic mutations alone. Social pressures on linguistic change are well documented; so, too, is the fact that not all languages exhibit the same degree of complexity, which is what we should expect if language is not the result of a human-specific cognitive adaptation. There’s evidence that points away from the Chomsky view, in other words.

If the evolution of linguistic structures is analogous to genetic replication, it would be very suggestive in relation to the debate over language origins. Suggestive, not definitive—linguistic structures and genes might be analogous, not homologous, and so the metaphor wouldn’t necessarily prove anything one way or the other. It would simply be interesting—and would suggest that language is perhaps grounded in biology rather than socialization—if languages replicate themselves along genetic lines.

The language/genes metaphor (part 1)

Part I: Rhetorical figures in science

I recently suggested that a parallel can be drawn between genetic evolution and the evolution of linguistic structures.

Is that a fair comparison? Is the language/genes metaphor appropriate?

I’ll attempt to answer that question in a series of posts. To begin with, however, we need to keep in mind that a metaphor is only valuable if it somehow aids research. A metaphor is, after all, a figure of speech, a comparison of unlike items. Unless it allows researchers to pose new questions, make new predictions, or guide inquiry in a new direction, then a metaphor at best offers a Sagan-esque elucidation, or, at worst, a misleading equivocation.

So, before interrogating the language/genes metaphor directly, I’ll use this post to look at the intersection of scientific research and a specific rhetorical figure–the incrementum, aka auxesis–in order to see what productive, generative figuration looks like more generally.

Jeanne Fahnestock’s Rhetorical Figures in Science is one of the most well-researched books on the subject. The book’s overall thesis is that rhetorical figures—which are syntactically available in all Indo-European and Sino-Tibetan languages, if not all languages full stop—that rhetorical figures offer scientists a way to “epitomize” their reasoning, to put complex information into a condensed (and thus easily evaluated) form.

Rhetorical figuration is what many people mean by ‘logical’ thinking. Pure logic is Aristotelian, deductive, syllogistic. However, not all rational thought proceeds by way of a syllogism. There are other lines of reasoning, as well, and since the time of the Greeks, most have been catalogued as the common topics and the rhetorical figures. The special characteristic of rhetorical figures is that they can encapsulate reasoning in a starkly precise form; herein lies their potentially productive power.

Fahnestock writes:

The figure is a verbal summary that epitomizes a line of reasoning. It is a condensed or even diagram-like rendering of the relationship among a set of terms, a relationship that constitutes the argument and that could be expressed at greater length. (24)

Of course, Fahnestock is sure to point out that not all reasoning—scientific or otherwise—can be epitomized formally via a rhetorical figure. The point is, figures are there as linguistic resources and sometimes scientists can use them to clarify their ideas . . . and to guide their research.

Fahnestock’s book explores the use of figuration in scientific literature, from Newton to materials engineering journals. One example she provides is particularly famous: Thomas Huxley’s search for the inorganic primordial soup that, he believed, had given rise to organic matter.

In his lab, Huxley had studied muddy ooze from the bottom of the ocean and found nothing of interest . . . until, ten years later, he “reexamined his bottled specimens under the microscope [and] discerned gelatinous bodies in the muck, bodies that he took to be the preserved specimens of loosely structured living forms, amorphous masses of protoplasm newly identified as the universal stuff of life” (Fahnestock 86). Huxley, it seemed, had discovered the Urschleim, the missing link between inorganic matter and organic life.

For Huxley and all early supporters of evolution, an exigent question was how organic life arose from inorganic substance. We might say ‘logic’ told Huxley that some mediating substance must exist or had once existed, but really, it is rhetorical figuration that allows the thought to be constructed, a substitution of A/B for A/somewhere between A and B/B. Or, in Huxley’s case, Inorganic/Bathybius haeckelii/Organic.

For Huxley, organic/inorganic was itself a rhetorical figure—an antithesis, or juxtaposition of contraries in parallel form. And, as Fahnestock points out, one way to break up an antithesis is with another figure—an incrementum—to show that the antithesis is simply two isolated steps in a larger, hitherto undiscovered series. An incrementum, then, is a series-making figure, one of many. And because series reasoning is particularly important for scientific thought, series-making figures can play a productive role in guiding scientific research, even when, as in Huxley’s case, the new research leads to a dead end.

Fahnestock again:

If species evolved from each other with no need for special creation, where did the first living form come from? How was the gulf between the inorganic and the organic first crossed? Huxley’s bathybius offered a potential answer to this immediate question and at the same time seemed to fulfill the speculations [the rhetorically figured speculations!] of the early nineteenth-century Naturphilosoph Lorenz Oken, who imagined that life had originated as an “Urschleim,” a “primitive mucous substance” generating itself from inorganic constituents in pools of sea water. Ernst Haeckel [another early Darwinian] seized on the possibility that bathybius generated itself spontaneously on the ocean floor and, as a structureless homogenous cellular material, represented the simplest of possible life forms. In this way, bathybius was rhetorically amplified by Haeckel and others into a vast layer of primitive living matter lying along the interface between rock and teeming sea, a widely distributed middle term between the inorganic and organic worlds. (87)

Unfortunately for Haeckel and Huxley, bathybius was neither primitive nor living. It was simply the byproduct of a chemical reaction called precipitation. They both admitted their mistake and moved on. However, the exigent question they were attempting to answer was and remains important, and we can thank series reasoning (the incrementum) for the rational and precise framing of the question.

Today, of course, biologists know there is no single item that bridges the antithesis organic/inorganic. And yet, there is

no reason to limit antithesis-mediating to a single third term; a coherent series of terms can be used instead. Currently, the search that inspired Huxley and Haeckel for a way to bridge the antithesis between the living and nonliving is being carried on by molecular biologists and virologists, but none of these researchers is looking for a single term as a sufficient intermediate. Instead, in the last thirty years, a host of forms have been identified that qualify to create what one virologist has called a “Continuum of Molecular Life Forms” (Levine 1992) . . . Everyone now working in this field is constructing an extended series of one kind or another. (90)

So here is a good example of productive rhetorical figuration in science. Series reasoning—based on the incrementum—has for a century served as the backbone, the framework for research into that gray area between organic and inorganic molecular structures.

(Another, simpler example of productive series reasoning comes from the study of our solar system. The asteroid belt was discovered after astronomers realized that a planetary gap existed between Mars and Jupiter. A simple formula known as Titus-Bode’s law calculated the distance between planetary orbits. Another god, the astronomers concluded, should exist between the war god and the sky god. So, astronomers—William Herschel among them—trained their telescopes on the part of the sky where, according to their mathematically supported incrementum, a new fourth planet should exist.)

So, the incrementum has helped scientists formulate ideas about what to look for (the simplest organic life forms) and where to look for them (between Mars and Jupiter). The figuration doesn’t do the work; it simply provides the conceptual framework. All figuration “epitomizes” a longer line of reasoning. Figuration is productive, however, if it allows scholars to make predictions or pose new questions.

Does the language/genes metaphor allow us to do those things? Or would a different metaphor—or a different figure altogether—be more productive?