Birds, all birds, and nothing but birds

I know, just when you thought it was ok to go back into the water. He’s back!! But rest assured this is a short one and I could not resist. It appears (see here) that biology has forsaken everything that our cognoscenti have taught us about evolution. We all know that it cannot be discontinuous. We all knowthat the continuity thesis is virtually conceptually necessary. We all knowthis because for years we have been told that the idea that linguistic facility in humans is based on something biologically distinctive that only humans have is as close to biologically incoherent as can be imagined. Anybody suggesting that that what we find in human languagemightbe biologically distinctive and unique is a biological illiterate. Impossible. Period. Creationism!

Well guess again. It seems that the bird voicebox, the syrinx, is biologically sui generis in the animal kingdom and “scientists have concluded that this voice box evolved only once, and that it represents a rare example of a true evolutionary novelty” (1). 

But surely they don’t mean ‘novelty’ when they say ‘novelty.’ Yup, that is exactly what they mean:

“It’s something that comes out of nothing,” says Denis Dubuole, a geneticist at the University of Geneva in Switzerland who was not involved with the work. “There is nothing that looks like a syrinx in any related animal groups in vertebrates. This is very bizarre.”

Now, as the little report indicates, true novelties are “hard to come by.” But, as the syrinx indicates, they are not conceptually impossible. It is biologically coherent to propose that these exist and that they can emerge. And that their distinctive properties are exactly what people like Chomsky have been suggesting is true of the recursive parts of FL (4).

They are innovations—new traits or new structures—that arise without any clear connections to existing traits or structures. 

Imagine that, no clear connections to other traits on other species or ancestors. Hmm. Are these guys really biologists? Probably not, or at least, not for long for very soon their credentials are sure to be revoked by the orthodox guardians of EvoLang. Save me! Save me! The discontinuitists are coming!

The report makes one more interesting observation: these kinds of qualitatively new innovations serve as interesting gateways for yet more innovation. Here, the development of the syrinx could have enabled songs to become more complex and biologists speculate that this might in turn have led to further speciation. In the language case, it is conceivable that the capacity for recursion in languageled to a capacity for recursion more generally in other cognitive domains. Think of arithmetic as a new song one can sing when hierarchical recursion has snuck in.  

Is all of this correct? Who knows? Today the claim is that the syrinx is a biological novelty. Tomorrow we might find out that it is less novel than currently advertised (recall for Minimalists, FL is unique but not thatunique. Just a teensy weensy bit unique). What is important is not whether it is unique, but the fact that biology and evolution and genetics have nothing against unique sui generic one of a kind features. They are rare, but not unheard of and not beyond the intellectual pale. That means that entertaining the possibility that something, say hierarchical recursion, is a unique cognitive capacity is not living out on the intellectual edge in evolutionary La-La land. It is a hypothesis and one that cannot be dismissed by assuming that this is not the way biology works or could work. It can so work and seems even to have done so on occasion. That means critics of the claim that language is a species specific capacity have to engage with the actual claims. Hand waving is simply dishonest (and you know who you are). 

Moreover, we know how to show that uniqueness claims are incorrect: just (ha!) show how to derive the properties of the assumed unique organ/capacity from more generic traits and show how the trait/organ under consideration could have continuously evolved from these using very itty bitty steps. Apparently, this was done for fingers and toes from fish fins. If you think that hierarchical recursion is “just more of the same” then find me the fins and show me the steps. If not, well, let’s just say, that the continuists have some work ahead of them (Lucy, you have some explaining to do) if they want to be taken seriously and that there is nothing biologically untoward or incoherent or wrong in assuming that sometimes, rarely but sometimes, novelties arise “without any clear connections to existing traits and structures.” And what better place to look for a discontinuity than in in language?

Let me end by adding two useful principles for future thinking on topics related to language and the mind:

1.     Chomsky is never (stupidly) wrong

2.     If you think that Chomsky is (stupidly) wrong go back to 1

Naturalized philosophy

I went to graduate school in philosophy a long time ago. At that time, there was a premium put on “naturalized” research, the idea being that good philosophy needed grounding in a “real” (non-philosophical) discipline. It was a time when Newton and Einstein and Boyle and Godel and Poincare joined the usual dead white European males that we all know and love in the pantheon of philosophical greats. In this setting, it is no surprise that Chomsky and his work made frequent appearances in the pages of the most prestigious philo journals and was a must read for a philosopher of language. It actually took some effort for the discipline to relegate Chomsky to the domain of “philosophical naïf” (I think this was Putnam’s phrase) and it coincided with endless debates about the implications of the referentialist worldview for narrow content and semantic meaning. IMO, this work did not deliver much in the way of insight, though it did manage to make quite a few careers. At any rate, Chomsky’s exit from the main stage coincided with a waning of the naturalizing project and a return to the metaphysical (and metalinguistic) abstruseness that philosophy is, it appears, endemically attracted to. If nothing else, de-naturalizing philosophy establishes academic protective boundaries providing philosophy with a proprietary subject matter that can protect deep thinkers from the naturalizers and their empirical pretentions.[1] Why do I mention this? Because I am a big fan of the kind of naturalized philosophy that the above mentioned luminaries practiced and so I am usually on the lookout for great examples thereof.

What are the distinctive marks of this kind of work? It generally rests on a few pretty “obvious” empirical premises and demonstrates their fertile implications. Chomsky’s work offers an excellent illustration.

What is Chomsky’s most significant contribution to philosophy (and indeed linguistics)? He identified three problems in need of solution: what does a native speaker know when s/he knows her/his native language? What meta-capacity underlies a native speaker’s capacity to acquire her/his native language? And how did this meta-capacity arise in the species?  These are the big three questions he put on the table. And the subsequent questions they naturally lead to: How do native speakers use their knowledge to produce and understand language, how do LADs use their meta-capacity to acquire their native capacity? How are one’s knowledge of language embodied in wetware?  The last three rely on glimmers of answers to the first three. Chomsky has taught us how to understand the first three. 

Here’s the argument. It is based on few really really really obvious facts. First, that nothing does language like humans do. Birds fly, fish swim, humans do language. It is a species specific capacity unlike anything we find anywhere else. Second, a native speaker displays linguistic creativity. This means that a native speaker can use and understand an unbounded number of linguistic objects never before encountered and does this relatively effortlessly. Third, any kid can reflexively acquire any language when placed in the right linguistic environment (linguistic promiscuity), an environment which, when one looks even moderately closely, vastly underdetermines the knowledge attained (poverty of the linguistic stimulus). These three facts make it morally certain that part of linguistic competence implies internalization of a G, that the human meta-capacity of interest involves a higher order capacity to acquire certain kinds of Gs and not others and that this meta-capacity rests on some distinctive species specific capacities of humans. These three conclusions rest solidly on these obvious facts and together they bring forth a research program: what properties to human Gs have and what is the fine structure of the meta-capacity. That Gs exist and that FL/UG exists is trivially true. What their properties are is anything but.[2]

As FoLers know, Chomsky has recently added a third question to the agenda: how FL/UG could possibly have arisen. He argues that the relative rapidity of the emergence of FL and its subsequent stability argues for an intriguing conclusion: that the change that took place was necessarily pretty small and that whatever is proprietary to language must be quite minor. I tend to think that Chomsky is right about this, and that it motivates a research program that (i) aims to limit what is linguistically special while (ii) demonstrating how this special secret sauce allows for an FL like ours in the context of other more cognitively and computationally general mental capacities it is reasonable to believe that our pre-linguistic ancestors enjoyed. Imo, this line of thinking is less solidly based on “obvious” facts, but the line of inquiry is sufficiently provocative to be very inviting. Again, the details are up for grabs, as they should be.

So what are the marks of naturalized philosophy? Identifying questions motivated by (relatively) straightforward facts that support a framework for asking more detailed questions using conventional modes of empirical inquiry. Chomsky is a master of this kind of thinking. But he is not alone. All of the above is actually in service of advertising another such effort by Randy Gallistel. The paper of interest, which is a marvelous piece of naturalized philosophy appeared here in TiCS. I want to say a word or two about it.

Gallistel’s paper is on the coding question. The claim is that this question has been effectively ignored in the cog-neuro world with baleful effects. The aim is to put it front and center on the research agenda and figure out what kind of neural system is compatible with a reasonable answer to that question. The argument in the paper is roughly as follows.

First, there is overwhelming behavioral evidence that animals (including humans) keeps track of numerical quantities (see box 1, (3)). Hence the brain must have a way to code for number. It must be able to store these numbers in some way and must be able to transmit this stored information in signals in some way. So it must be able to write this information to memory and read this information from memory.

Second, if the brain does code for number it must do so in some code. There are various kinds, but the two the paper discusses are hash/rate/tally codes vs combinatorial codes (4-5). The former are “unary” codes. What this means is that “to convey a particular number one must use as many code elements are the numerosity to which the number refers.” Thus, if the number is 20 then there are 20 hash marks/strokes/dotes whatever representing the number.

The paper distinguishes such codes from “combinatorial” codes. These are the ones we are familiar with. So for example, ‘20’ conveys the number 20 and does so by using 10 digits in order sensitive configurations (i.e. 21 differs from 12). Note, combinatorial code patterns are not isomorphic to the things they represent.[3] 

The paper explores the virtues of combinatorial codes as against hash/rate/tally codes. The latter are “vastly more efficient” by orders of magnitude. Rate codes “convey 1 bit per spike” (5) while it is known that spike trains convey between 3-7 bits per spike. Rate codes are very energy expensive, combinatorial codes can be “exponentially smaller” (6). Last of all, there is evidence that spike trains use combinatorial codes because “reordering the intervals changes the message” (recall ‘21’ vs ‘12’), as expected if they spike trains are expressing a combinatorial code. 

The conclusion: the brain uses a combinatorial code, and this is interesting because this seems to require that the code be “symbolic” in the sense that its abstract (syntactic) structure matters for the information being conveyed.  And this strongly suggests that this info is not stored in synapses as supposed in a neural net system.

This last conclusion should not be controversial. When first put on the market of ideas, neural nets were confidently sold as being non-representational. Rumelhart and McClelland focused on this as one of their more salient properties and Fodor and Pylyshyn criticized such models for precisely this reason. The Gallistel paper is making the additional point that being asymbolic is, in addition to being cognitively problematic, is also neurophysiologically a problem as the kind of codes we are pretty sure we need are the kinds that neural nets are designed not to support. And this means that these are the wrong neuro models for the brain: “In neural net models, plastic synapses are molded by experience” and were intended to model “associative bonds” which “were never conceived of as symbols, and neither are their neurobiological proxies” (8).

Note, we can conclude that neural nets are the wrong model even if we have no idea what the correct model is. We can know what kind of code it is and what this means for the right neurophysiology without knowing what the right neurophysiology is. And if the codes are combinatorial/symbolic then there is no way that the right physiology for memory can be neural nets. This takes the Fodor-Pylyshyn critique on major step further.

So, if not in nets, what kind of architecture. Well, you all know by now. The paper notes that we can get everything we want from a chemical computer. We can physically model classical von Neuman/Turing machines in chemistry, with addresses, reading from, writing to, etc. Moreover, chemical computation has some nice biological features. Complex chemicals can be very stable for long periods of time (what we want from a long term memory store), and writing to such molecules is very energy efficient (8). In addition, chemical computing can be fast (some “can be altered on a nanosecond time scale”) and we know of instances of this kind of chemical computing that are behaviorally relevant. Last chemical computations are very energy efficient. Both storing and computing can be done cheaply if done chemically.

All of this leads to the conclusion that the locus of neurobiological computing is chemical and where are the relevant chemicals? Inside the cell. So, in place of neural nets we have the “cell intrinsic memory hypothesis” (1). Happily, there is now evidence that some computing gets done intra-celluarly (1-2). But if some gets done there…

This paper is great naturalized philosophy: we argue from pretty simple behavioral evidence that a certain kind of coding format is required and then that these kinds of formats prefer certain kinds of physical systems to support such codes and end with conclusions about the locus of the relevant computations. Thus we move from numbers are required, to combinatorial codes are the right kind, to neural nets won’t cut it to chemical computing within the cell. The big open meaty empirical question is what particular combinatorial code is exploited. It’s the cog-neuro analogue of how DNA stores genetic information and uses it. Right now, we do not know. At all.

This last analogy to DNA is important, and, IMO, is the strongest reason for thinking that this line of thinking is correct. Conventional computers provide an excellent model of how computation can be physically implemented. We know how to chemically “build” a conventional computer. We know that biology already uses chemistry to store and use information in hereditary and development. Is it really plausible that this in place machinery is not used for cognitive computation? Or as the paper puts it in the last sentence: “Why should the conveyance of acquired information proceed by principles fundamentally different from those that govern the conveyance of heritable information?” Why indeed! Isn’t the contrary assumption (the machinery is there for the using but it is never used) biologically scandalous? Wouldn’t Darwin be turning in his grave if he considered this? Isn’t assuming it to be false a kind of cognitive creationism? Yup, connetionists and neural net types are the Jerry Falwells of biology! Who would have thunk it: the road from Associationsim to Creationism is paved with Empiricist intentions. Only Rationalism and Naturalized Philosophy can save you.

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[1] Let me quickly add that I consider philosophy training a very useful aid to right thinking. Nothing allows you to acquire the feel for good argumentation than a stressful philosophical workout. And by “good” I mean understanding how premises related to conclusions, how challenging premises can allow one to understand how to evaluate conclusions, understanding that it is always reasonable to ask what would happen to a conclusion should such and such a premise be removed etc.  In other words, philosophy prizes deductive structure and this is a useful talent to nurture regardless of what conclusions you are interested in netting and premises you are interested in frying.

[2] Chomsky, as you all know, not only posed the questions but showed how to go about empirically investigating them. This is what puts him in with the Gods: he discovered interesting questions and figured out technology relevant to answering them.

[3] Thus, the numeral’s patterning represents the number in the former but not the latter. The difference between the two kinds of codes is similar to the one made (here) between patterns that track the patterning and those that do not.

Inference to some great provocations

David Berlinsky is editing a newish online magazine Inference that articles in which I have mentioned in several previous posts. The latest issue is full of fun for linguists as there are four articles of immediate relevance. Here’s the link for the issue. Let me say a word or two about the pieces.

The first is an essay by Chomsky that goes over familiar ground regarding the distinctive nature of human linguistic capacity. He observes that this observation has a Cartesian pedigree and that language was recognized as distinctive (all and only humans have it) and wondrous (it was free and capable of expressing unboundedly many thoughts) and demanding of some kind of explanation (it really didn’t fit in well with what was understood to be the causal structure of the physical world) as early as it was noticed.

As Chomsky notes, Cartesians had relatively little of substance to say about the underpinnings of this wondrous capacity, mainly because the 17^th century lacked the mathematical tools for the project. They had no way of describing how it was possible to “make infinite use of finite means” as von Humboldt put it (2). This changed in the 20^th century with Church, Godel, Post and Turing laying the foundations of computation theory. This work “demonstrated how a finite object like the brain could generate an infinite variety of expressions.” And as a result, “[i]t became possible, for the first time, to address part of” the problem that the Cartesians identified (2).

Note the ‘part of’ hedge. As Chomsky emphasizes, the problem the Cartesians identified has two parts. The first, and for them the most important feature, is the distinction between “inclined” vs “impelled” behavior (3). Machines are impelled to act, never “inclined.” Humans, being free agents, are most often “inclined” (though they can be “compelled” as well). Use of language is the poster child for inclined behavior. Cartesians had no good understanding of the mechanics of inclination. As Chomsky observes, more than 300 years later, neither do we. As he puts it, language’s “free creative use remains a mystery,” as does free action in general (e.g. raising one’s hand) (3).

The second part, one that computation theory has given us a modest handle on, is the unbounded nature of the thoughts we can express. This feature very much impressed Galileo and Arnauld & Lancelot and von Humboldt, and it should impress you too! The “infinite variety” of meaningfully distinct expressions characteristic of human language “surpasse[s] all stupendous inventions” (1).  Chomsky has redubbed this feature of language “the Basic Property” (BP). BP refers to a property of the human brain, “the language faculty,” and its capacity to “construct a digitally infinite array of structured expressions” each of which “is semantically interpreted as expressing a thought, and each can be externalized by some sensory modality such as speech” (2).  BP is what GG has been investigating for the last 60 years or so. Quite a lot has been discovered about it (and yes, there is still lots that we don’t know!).

Chomsky emphasizes something that is worth reemphasizing: these facts about language are not news. That humans have linguistic creativity in the two senses above should not really be a matter of dispute. That humans do language like no other animal does should also be uncontroversial. How we do this is a very tough question, only a small part (very small part) of which we have managed to illuminate. It is sad that much debate still circulates around the whether question rather than the how. It is wasted time.

An important theme in Chomsky’s essay turns on how the world looks when we have no idea what’s up. Here is a quote that I believe all good scientifically inclined GGers should have tattooed to themselves (preferably in some discrete place) (3):

When understanding is thin, we expect to see extreme variety and complexity.

Absolutely! Variety and complexity are hallmarks of ignorance. And this is why progress and simplicity go hand in hand. And this is why I have clasped to my heart Dresher’s apposite dictum: There should be only two kinds of papers in linguistics: (i) papers that show that two things that look completely different are roughly the same and (ii) papers that show that two things that are roughly the same are in fact identical. These are the papers that highlight our progressively deeper understanding. Complication is often necessary, but it is progressive just in case it paves the way for greater simplicity.

The unification and simplicity is, thus, a leading indicator of scientific insight. Within linguistics it has a second function. It allows one to start addressing the issue of how FL might have evolved.  Here’s Chomsky:

In the analysis of the Basic Property, we are bound to seek the simplest computational procedure consistent with the data of language. Simplicity is implicit in the basic goals of scientific inquiry. It has long been recognized that only simple theories can attain a rich explanatory depth. “Nature never doth that by many things, which may be done by a few,” Galileo remarked, and this maxim has guided the sciences since their modern origins. It is the task of the scientist to demonstrate this, from the motion of the planets, to an eagle’s flight, to the inner workings of a cell, to the growth of language in the mind of a child. Linguistics seeks the simplest theory for an additional reason: it must face the problem of evolvability. Not a great deal is known about the evolution of modern humans. The few facts that are well established, and others that have recently been coming to light, are rather suggestive. They conform to the conclusion that the language faculty is very simple; it may, perhaps, even be computationally optimal, precisely what is suggested on methodological grounds.

Unless FL is simpler than we have considered it to be up till now (e.g. far simpler than say GBish models make it out to be) then there is little chance that we will be able to explain its etiology. So there are both general methodological grounds for wanting simple theories of FL and linguistic internal reasons for hoping that much of the apparent complexity of FL is just apparent.

Chomsky’s piece proceeds by rehearsing in short form the basic minimalist trope concerning evolvability. First, that we know little about it and that we will likely not know very much about it ever. Second, that FL is a true species property as the Cartesians surmised. Third, that FL has not evolved much since humans separated. Fourth, that FL is a pretty recent biological innovation. The third and fourth points are taken to imply that the Basic Property aspect of FL must be pretty simple in the sense that what we see today pretty well reflects the original evo innovation and so its properties are physically simple in that they have not been shaped by the forces of selection. In other words, what we see in BP is pretty much undistorted by the shaping effects of evolution and so largely reflect the physical constraints that allowed it to emerge.

All of this is by now pretty standard stuff, but Chomsky tells it well here. He goes on to do what any such story requires. He tries to illustrate how a simple system of the kind he envisions will have those features that GG has discovered to be characteristic of FL (e.g. structure dependence, unboundedly many discrete structures capable of supporting semantic interpretation etc.). This second step is what makes MP really interesting. We have a pretty good idea what kinds of things FL concerns itself with. That’s what 60 years of GG research has provided. MP’s goal is to show how to derive these properties from simpler starting points, the simpler the better. The target of explanation (the explanadum) are the “laws” of GB. MP theories are interesting to the degree that they can derive these “laws” from simpler more principled starting points. And, that, Chomsky argues, is what what makes Merge based accounts interesting, they derive features that we have every reason to believe characterize FL.[1]

Two other papers in the issue address these minimalist themes. The first is a review of the recent Berwick & Chomsky (B&C) book Why only us. The second is a review of a book on the origins of symbolic artifacts. Cederic Boeckx (CB) reviews B&C. Ian Tatersall (IT) reviews the second. The reviews are in interesting conflict.

The Boeckx review is quite negative, the heart of the criticism being that asking ‘why only humans have language’ is the wrong question. What makes it wrong? Well, frankly, I am not sure. But I think that the CB review thinks that asking it endorses a form of “exceptional nativism” (7) that fails to recognize “the mosaic character of language,” which, if I get the point, implies eschewing “descent with modification” models of evolution (the gold standard according to CB) in favor of “top-down, all-or-nothing” perspectives that reject comparative cognition models (or any animal models), dismiss cultural transmission as playing any role in explaining “linguistic complexity” and generally take a jaundiced view of any evolutionary accounts of language (7-8). I actually am skeptical regarding any of this.

Before addressing these points, however, it is interesting that IT appears to take the position that CB finds wrong-headed. He thinks that human symbolic capacities are biologically quite distinctive (indeed “unique”) and very much in need of some explanation. Moreover, in contrast to CB, IT thinks it pretty clear that this “symbolic activity” is of “rather recent origin” and that, “as far as can be told, it was only our lineage that achieved symbolic intelligence with all of its (unintended) consequences” (1). If we read “symbolic” here to mean “linguistic” (which I think is a fair reading), it appears that IT is asking for exactly the kind of inquiry that CB thinks misconceived.

That said, let’s return to CB’s worries. The review makes several worthwhile points. IMO, the two most useful are the observation that there is more to language evolution than the emergence of the Basic Property (i.e. Merge and discretely infinite hierarchically structured objects) and that there may be more time available for selection to work its magic than is presupposed.  Let’s consider these points in turn.

I think that many would be happy to agree that though BP is a distinctive property of human language it may not be the only distinctive linguistic property. CB is right to observe that if there are others (sometimes grouped together as FLW vs FLN) then these need to be biologically fixed and that, to date, MP has had little to say about these. One might go further; to date it is not clear that we have identified many properties of FLW at all. Are there any?

One plausible candidate involves those faculties recruited for externalization. It is reasonable to think that once FLN was fixed in the species, that linking its products to the AP interface required some (possibly extensive) distinctive biological retrofitting. Indeed, one might imagine that all of phonology is such a biological kludge and that human phonology has no close biological analogues outside of humans.[2] If this is so, then the question of how much time this retrofitting required and how fast the mechanisms of evolution (e.g. selection) operate is an important one. Indeed, if there was special retrofitting for FLW linguistic properties then these must have all taken place before the time that humans went their separate ways for precisely the reasons that Chomsky likes to (rightly) emphasize: not only can any human acquire the recursive properties of any G, s/he can also acquire the FLW properties of any G (e.g. any phonology, morphology, metrical system etc.).[3] If acquiring any of these requires a special distinctive biology, then this must have been fixed before we went our separate ways or we would expect, contrary to apparent fact, that e.g. some “accents” would be inaccessible to some kids. CB is quite right that it behooves us to start identifying distinctive linguistic properties beyond the Basic Property and asking how they might have become fixed. And CB is also right that this is a domain in which comparative cognition/biology would be very useful (and has already been started (see note 2). It is less clear that any of this applies to explaining the evolution of the Basic Property itself.

If this is right, it is hard for me to understand CB’s criticism of B&C’s identification of hierarchical recursion as a very central distinctive feature of FL and asking how it could have emerged.  CB seems to accept this point at times (“such a property unquestionably exists” (3)) but thinks that B&C are too obsessed with it. But this seems to me an odd criticism. Why? Because B&C’s way into the ling-evo issues is exactly the right way to study the evolution of any trait: First identify the trait of interest. Second, explain how it could have emerged.  B&C identify the trait (viz. hierarchical recursion) and explain that it arose via the one time (non-gradual) emergence of a recursive operation like Merge. The problem with lots of evo of lang work is that it fails to take the first step of identifying the trait at issue. But absent this any further evolutionary speculation is idle. If one concedes that a basic feature of FL is the Basic Property, then obsessing about how it could have emerged is exactly the right way to proceed.

Furthermore, and here I think that CB’s discussion is off the mark, it seems pretty clear that this property is not going to be all that amenable to any thing but a “top-down, all-or-nothing” account. What I mean is that recursion is not something that takes place in steps, a point that Dawkins made succinctly in support of Chomsky’s proposal (see here). As he notes, there is no such thing as “half recursion” and so there will be no very interesting “descent with modification” account of this property. Something special happened in humans. Among other things this led to hierarchical recursion. And this thing, whatever it was, likely came in one fell swoop. This might not be all there is to say about language, but this is one big thing about it and I don’t see why CB is resistant to this point. Or, put another way, even if CB is right about many other features of language being distinctive and amenable to more conventional evo analysis, it does not gainsay the fact that the Basic Property is not one of these.

There is actually a more exorbitant possibility that perhaps CB is reacting to. As the review notes (7): “Language is special, but not all that special; all creatures have special abilities.” I don’t want to over-read this, but one way of taking it is that different “abilities” supervene on common capacities. This amounts to a warning not to confuse apparent expressions of capacities for fundamental differences in capacities. This is a version of the standard continuity thesis (that Lenneberg, among others, argued is very misleading (i.e. false) wrt language). On this view, there is nothing much different in the capacities of the “language ready” brain from the “language capable” brain. They are the same thing. In effect, we need add nothing to an ape brain to get ours, though some reorganization might be required (i.e no new circuits). I personally don’t think this is so. Why? For the traditional reasons that Chomsky and IT note, namely that nothing else looks like it does language like we do, even remotely. And though I doubt that hierarchical recursion is the whole story (and have even suggested that something other than Merge is the secret sauce that got things going), I do think that it is a big part of it and that downplaying its distinctiveness is not useful.

Let me put this another way. All can agree that evolution involves descent with modification. The question is how big a role to attribute to descent and how much to modification (as well as how much modification is permitted). The MP idea can be seen as saying that much of FL is there before Merge got added. Merge is the “modification” all else the “descent.” There will fe features of FL continuous with what came before and some not continuous. No mystery about the outline of such an analysis, though the details can be very hard to develop. At any rate, it is hard for me to see what would go wrong if one assumed that Merge (like the third color neuron involved in trichromatic vision (thx Bill for this)) is a novel circuit and that FL does what it does by combining the powers of this new operation with those cognitive/computational powers inherited from our ancestors. That would be descent with modification. And, so far as I can tell, that is what a standard MP story like that in B&C aims to deliver. Why CB doesn’t like (or doesn’t appear to like) this kind of story escapes me.

Observe that how one falls on the distinctiveness of BC issue relates to what one thinks of the short time span observation (i.e. language is of recent vintage so there is little time for natural selection or descent with modification to work its magic). The view Chomsky (and Berwick and Dawkins and Tatersall) favor is that there is something qualitatively different between language capable brains and ones that are not. This does not mean that they don’t also greatly overlap. It just means that they are not capacity congruent. But if there is a qualitative difference (e.g. a novel kind of circuit) then the emphasis will be on the modifications, not the descent in accounting for the distinctiveness. B&C is happy enough with the idea that FL properties are largely shared with our ancestors. But there is something different, and that difference is a big deal. And we have a pretty good idea about (some of) the fine structure of that difference and that is what Minimalist linguistics should aim to explain.[4] Indeed, I have argued and would continue to argue that the name of the Minimalist game is to explain these very properties in a simple way. But I’ve said that already here, so I won’t belabor the point (though I encourage you to do so).

A few more random remarks and I am done. The IT piece provides a quick overview of how distinctive human symbolic (linguistic?) capacities are. In IT’s view, very. In IT’s view, the difference also emerged very recently, and understanding that is critical to understanding modern humans. And he is not alone. The reviewee Genevieve von Petziger appears to take a similar view, dating the start of the modern human mind to about 80kya (2). All this fits in with the dates that Chomsky generally assumes. It is nice to see that (some) people expert in this area find these datings and the idea that the capacity of interest is unique to us credible. Of course, to the degree that this dating is credible and to the degree that this is not a long time for evolution to exercise its powers the harder the evolutionary problem becomes. And, of course, that’s what makes the problem interesting. At any rate, what the IT review makes clear is that the way Chomsky has framed the problem is not without reasonable expert support. Whether this view is correct, is, of course, an empirical matter (and hence beyond my domain to competently judge).

Ok, let me mention two more intellectual confections of interest and we are done. I will be short.

The first is a review of Wolfe’s book by David Lobina and Mark Brenchley. It is really good and I cannot recommend it highly enough. I urge you in particular to read the discussion on recursion as self-reference vs self-embedding and the very enlightening discussion of how Post’s original formalism (might have) led to some confusion on these issues. I particularly liked the discussion of how Merge de-confuses them, in effect by dumping the string based conception of recursion that Post’s formalism used (and which invited a view of recursion as self-embedding) and implementing the recursive idea more cleanly in a Merge like system in which linguistic structures are directly embedded in one another without transiting through strings at all. This cleanly distinguishes the (misleading) idea that the recursion lies with embedding clauses within clauses from the more fundamental idea that recursion requires some kind of inductive self-reference. Like I said, the discussion is terrific and very useful.

And now for desert: read David Adger’s fun review of Arrival. I confess that I did not really like the movie that much, but after reading David’s review, I intend to re-see it with a more open mind.

That’s it. Take a look at the issue of Inference. It’s nice to see serious linguistic issues intelligently discussed in a non-specialist’s venue. It can be done and done well. We need more of it.

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[1] Chomsky also mentions that how lexical items have very distinctive properties and that we understand very little about them. This ahs become a standard trope in his essays, and a welcome one. It seems that lexical items are unlike animal signs in that the latter are really “referential” in ways that the former are not. The how and whys behind this, however, is completely opaque.

[2] There has been quite a lot of interesting comparative work done, most prominently by Berwick, on relating human phonology with bird song. See here and here for some discussion and links.

[3] There is another possibility: once FLN is in place there is only one way to retrofit all the components of FLW. If so, then there is no selection going on here and so the fact that all those endowed with FLNs share common FLWs would not require a common ancestor for the FLWs. Though I know nothing about these things, this option strikes me as far-fetched. If it is, then the logic that Chomsky has deployed for arguing that FLN was in place before humans went their separate ways would hold for FLW as well.

[4] CB makes a claim that is often mooted in discussions about biology. It is Dobzhansky’s dictum that nothing in biology makes sense except in the light of evolution. I think that this is overstated. Lots of biology “makes sense” without worrying about origin. We can understand how hearts work or eyes see or vocal tracts produce sounds without knowing anything at all about how they emerged. This is not to diss the inquiry: we all want to know how things came to be what they are. But the idea that natural selection is the only thing that makes sense of what we see is often overblown, especially so when Dobzhansky quotes are marshaled. For some interesting discussion of this see this.