Tuesday, May 4, 2010

Below are excerpts from an excellent review. The parts reproduced relate to the namture of language, and the utter lack of evidence that animals possess anything resembling laguage.

« REVIEWS «Biolinguistics 2.2: 185–194, 2008ISSN 1450–3417 http://www.biolinguistics.euNovel Tools at the Service of Old IdeasJablonka, Eva & Marion J. Lamb. 2005. Evolution in Four Dimensions. Cambridge,MA: MIT Press.By Massimo Piattelli–Palmarini2. Symbols? Oh, No, Please!As of Chapter 6, I start to disagree with J&L. They follow a very old script, onethat opens up with the appearance of symbolic systems. They duly acknowledgethat language is special, with respect to other symbolic communication systemsfound in animals, essentially because of the subtlety of syntax. That is correct, butthere is more to be said. Other crucial differences are to be found already at thelevel of the lexicon. It’s not just syntax that makes human language special, butalso the nature of individual words and the way they connect with each otherand with the world. There are at least four major differences between words andall non-linguistic symbols: (A) aspectual reference, (B) headedness, (C) internalstructure, and (D) edge features. Briefly about each one in turn:(A) Buy and sell, fear and frighten, and a huge variety of such oppositions, in alllanguages, refer to a same objective, physical, filmable, state of affairs, buthave transparently different meanings. The same applies to nouns (destructionvs. demolition, gift versus theft) and to adjectives (thrifty vs. stingy,abundant versus excessive, and so on). Even apparently innocent words likecity embody an aspectual component, a point of view. Words refer onlyunder specific itineraries of mental access (a city can be said to be chaotic,polluted, expensive, mostly Victorian, each expression obviously referringto very different objective features; cf. Chomsky 2005). Word meanings arethrough and through intensional. No symbol used in animal communicationsystems has this property. Also many non-linguistic symbols usedby humans to communicate lack it, unless they are transparently parasiticon language.(B) ‘The California highway commissioner report’ is a report. ‘The world tradeexchange bank’ is a bank. ‘The spy who came in from the cold’ is a spy. Therightmost noun (in English, the leftmost in other languages) heads allnominal compounds. A noun with a determiner (such as the spy) heads theDeterminer Phrase, even when the DP contains a whole sentence (who camein from the cold). Headedness also applies to Verb Phrases (in a morecomplicated way which need not detain us here; see below). The propertyof headedness is conserved by the syntactic derivation, from start to finish,and cannot be altered. It’s a crucial combinatorial valency of lexical entries,determining the category to which they belong and how the syntacticmachinery must treat them. There are, of course, many ways to make acertain symbol particularly salient in a string of non-verbal symbols (size,color, etc.), but headedness is unique to words.(C) Words have a rich internal structure. Thematic roles are probably the mostconspicuous such structures. There was the destruction of Carthage by Scipio,but there cannot be *the sleep of the bed by Scipio. Together with headedness,thematic roles are crucial valencies for combination into larger expressions.Morphological domains within words are also central, with relations ofdominance and asymmetry. Vast, subtle, and ramified consequences of thisinternal structures ensue for syntax and semantics (Halle & Marantz 1993,di Sciullo 2005). No other system of non-linguistic symbols has any sem blanceof such property.(D) Very simply said, words are “sticky” and so are phrasal constituents obtainedby merging two of them, and then merging this compound withother words, again and again, recursively and hierarchically. (The technicalterm for this intrinsic combinatorial power of words and phrasal constituentsin the minimalist program is “edge features”; Chomsky has rightlystressed that the appearance of edge features has been one of the centralevents in the evolution of language.) Whole linguistic expressions, andsentences in particular, are not lists of words, not even ordered lists ofwords. The point I wish to emphasize here is that words have the intrinsiccapacity to project structure “upwards” onto larger compounds. Verbsoffer the richest case, but not the only one. Verbs project a stratification of“shells” in a fixed hierarchical order, specifying the place where to insertthe actants, the auxiliaries, the checking of tense, Case and agreement, andmore (ever since the seminal work of Richard Larson — cf. Larson 1988).All in all, therefore, contrary to spontaneous intuition, contrary to the wholedomain of semiotics, and contrary to what Chapter 6 and Chapter 9 of J&Lsuggest, there is no gain in our understanding of language by assimilating it to asystem of symbols. Any attempt to reconstruct language evolution as theevolution of a symbolic system leads us badly astray. Words are, of course, insome sense, symbols, and they enter into the system of language, but the uniqueproperties summarized here above make words stand radically apart from allother symbolic systems. J&L, unbeknownst to them, seal this radical separationin the last line of their table on p. 234, when they state that the “range ofvariation” of symbolic systems is “unlimited”. I doubt that they are right evenabout symbolic systems, but surely this does not apply to language. The range ofvariation for language is quite severely limited, as J&L sketch in Chapter 8, sortof noncommittally, when speaking of the “principles and parameters” model(Baker 2001, 2003). Symbolic systems are not relevant to language, and theycannot be offered as an intermediate step in language evolution.3 . Culture and LanguageJ&L embrace a thesis that several other authors also have tried to promote: theshaping of language by culture and history. Their critique of the innatist,modularist, and highly specific nature of language has, as is often the case withthose who adopt their position, a possibilistic attitude: Why could we not, oneday, explain a lot in language by means of cultural and historical factors, communicativefunctions, motor control, and general intelligence? This line was offeredover 30 years ago already by Jean Piaget to Noam Chomsky, in a direct debate(Piattelli–Palmarini 1980). The answer is today what it was then: No one canexclude this possibility, as a remote possibility. It is, however, eminently rationalto expect that it will not happen. The task seems even more hopeless today than itseemed 35 years ago, because we know a lot more about language than we didthen. For instance, none of the properties of words that I have sketched above canbe explained in terms of culture or history, or motor control, or factors of generalintelligence.On p. 218, J&L venture into a minefield, quite similar to the one into whichMichael Arbib also ventured in BBS recently (Arbib 2005) — a parallel betweenl anguage and mathematics:Although the speed and ease of learning [of language by the child] mayindicate that there are some preexisting specifically selected neural mechanisms,the same properties could also be due to a culturally evolved systemthat is well adapted to the brain, and therefore makes learning easy. Forexample, think how difficult it was 1200 years ago for someone in Europe todivide one number by another. Say they wanted to divide 3712 by 116 […][they point to the impracticality of the Roman numerals — MPP] Today, with ourArabic notation system (and the useful zero), it would take the average tenyear-old only minutes to get the answer 32.No genetic change, no brain change, but rather a cultural invention that hasbecome common knowledge. J&L advocate (like Arbib and Deacon andTomasello) a co-evolution of brain and language and do not advocate a purelycultural-evolution explanation of the language capacity. Well, anyway, theiranalogy with the numerical division is totally irrelevant. No sentence in anylanguage requires “minutes” to be understood by a ten-year-old, or by anyone atany age. Aside from the fact that ten years is a very old age for language,sentences are processed in fractions of seconds, not minutes, today just as theywere 1200 years ago, or earlier. Moreover, the number system and the rules fordividing numbers have to be explicitly and painfully taught. No three-year-oldchild today can make that division, while he or she can well understand quitesubtle syntactic constructions, exactly like a child could already in ancient Egypt.The analogy is infelicitous, because language is in a completely different ballpark.Like this one, many analogies and thought-experiments offered by J&L inthe domain of language are inconsequential or misleading, unlike those that dealwith biology proper.4. New Biology and Old ReflexesA most puzzling aspect of this book is that, after having pleaded persuasively fora major expansion of concepts and models in evolutionary theory, J&L fall backonto a basically classic, neo-Darwinian, functionalist explanation of the evolutiono f language. Just as an example, on p. 339 we read:Two related sets of conditions seem to have pushed our ancestors along theroute to language. The first was an altered ecological and socialenvironment, which provided a strong and persistent motivation for bettercommunication […]. The second and related set of conditions has to do withanatomy and physiology. […] It was probably the increased motor controlover hand movements and vocalizations, and the ability to imitate bothgestures and vocal sounds.They are in excellent and very old company in making these hypotheses, fromDarwin himself, to Jean Piaget, Philip Liberman, Steven Pinker, Paul Bloom,Michael Arbib, and Derek Bickerton, just to name a few. Yet, all that we havelearned from the new biology, and from this very book, should make any suchfunctionalist hypothesis unnecessary or even suspect. Master regulatory geneswith pleiotropic effects, transposons, gene duplications, histone modification,and alternative gene splicing (just to mention a few) offer manifold evolutionarymechanisms that make progressive functional adaptation quite marginal. ButJ&L insist, venturing into “non-genetic inheritance” to explain how “variousfeatures of the emerging language system that were initially culturally transmittedwere later genetically assimilated” (p. 340, my emphasis). I have no qualm withnon-genetic inheritance, amply attested in experiments well explained in theirown previous chapters and also endorsed by Cherniak’s “non-genomic nativism”(which J&L ignore — see supra), but I strongly object to the cultural transmissionhypothesis.Hauser, Chomsky & Fitch (2002) have rightly insisted on the uniqueness ofthe capacity of humans to acquire a lexicon, and on the presence in humans ofBiolinguistics « Special «190syntactic computational powers that are conspicuously absent in other primates(Fitch & Hauser 2004). Together with the very special properties of words seenabove, these are quantum changes in cognitive powers, both qualitatively andquantitatively, impossible to reconstruct by piecemeal functional adaptation.Cultural interactions among humans that are allowed by language presupposethem and cannot explain their gradualistic adaptive origin. The new evolutionarymechanisms presented in this book could have finally dispensed us from exploringagain an old dead-end.The surprising reappearance of old, standard neo-Darwinism is also to bewitnessed when J&L criticize the approach promoted by Hauser, Chomsky &Fitch in an already famous (or infamous, for some; cf. Pinker & Jackendoff 2005)paper published in 2002 (Hauser, Chomsky & Fitch 2002). They surprisinglyrepeat en passant the most routine neo-Darwinian objections.I must also point out that in Chapter 9, J&L choose to tell us the story of thechimp Kanzi and the data collected by Sue Savage–Rumbaugh, allegedlyshowing important continuity between the symbolic system mastered by apes(after long training) and human language. They fail to even mention the case ofthe chimpanzee Nim Chimpsky which led to drastically opposite conclusions.After several years of daily cohabitation and of daily sessions of several hourstrying to teach Nim American Sign Language, Laura Petitto, Herbert Terrace, andThomas G. Bever concluded that no real progress had been made. This momentouspiece of work (Terrace et al. 1979) as well as the papers and book by DavidPremack (Premack 1972, 1986), that for many of us closed the chapter of thesearch for animal language, should at least have been presented, if only tocriticize them.