on the human- rethinking the natural selection of human language by terrence w. deacon

7/22/2019 On the Human- Rethinking the Natural Selection of Human Language by Terrence W. Deacon

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On The Human: Rethinking The Natural

Selection Of Human Language

by: Terrence W. Deacon

February 14th, 2010

Introduction

Since Darwins time, the human language capacity has been a perennially cited paragon of extreme

complexity that defies the explanatory powers of natural selection. And it is not just critics of

Darwinism who have argued that this most distinctive human capacity is problematic. Alfred Russel

Wallacethe co-discoverer of natural selection theory and in many ways more of an ultra-Darwinian

than Darwin himselffamously argued that the human intellectual capacity which makes languagepossible, is developed to a level of complexity that far exceeds what is achievable through natural

selection alone. While fiercely defending natural selection theory with respect to the traits of other

species, he argued that in the case of humans, natural selection could only have endowed the

savage with a brain a little superior to that of an ape. (p. 392) And Charles Lyellwho personally

promoted Darwins work and generally supported the evolutionary perspectivealso worried that

language was just too complex to have evolved by natural means. Not only are the vast vocabulary

and baroquely structured grammar and syntax of even the most simple of natural languages orders of

magnitude more complex than any other species communication system, but the capacity this all

provides for expressing esoteric concepts and conveying aesthetic experiences seems far removed from

anything with direct adaptive consequence.

Darwin himself fretted over the possibility that natural selection alone might be incapable of

accounting for exaggerated functional complexity in nature. In a letter he wrote to Asa Gray shortly

after the publication of On the Origin of Species, he admits that The sight of a feather in a peacocks

tail, whenever I gaze at it, makes me feel sick! Despite the spectacular and elaborately formed details

of this adornment, it was a burden that negatively impacted health and survival and so could not have

been the subject to natural selection with respect to the environment. But it was the extravagance of

traits such as this, despite their lack of utility, that suggested to Darwin an approach to the challenge

of explaining human mental capacities.

In the case of the peacock tail, and other similar traits, Darwin realized that, indeed, something other

than natural selection with respect to environmental conditions was responsible. Recognizing that

reproduction rather than individual survival was the critical factor in evolution, he argued that

competition with respect to reproductive access (sexual selection) could result in runaway selection on

certain traits, independent of their environmental suitability. Darwin argued that a display feature or

fighting ability that led an individual to out-compete others in gaining access to mates would also

favor proliferation and evolutionary exaggeration of these traits, even at some cost to individual

health and survival. Analogously, he postulated that selection with respect to sex might also explain


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such extravagant and highly divergent traits as human language. In his book The Descent of Man and

Selection in Relation to Sexwhich is typically referred to by only the first half of its titlehe argues

that language and other human traits that appear exaggerated beyond survival value, can be explained

as consequences of sexual selection. So, for example, he imagines that language might have evolved

from something akin to bird song, used as a means to attract mates, and that the ability to produce

highly elaborate vocal behaviors was progressively exaggerated by a kind of arms-race competition forthe most complex vocal display.

Unfortunately, there are strong reasons for doubting the relevance of sexual selection to this most

distinctive of human traits. This is because sexual selection inevitably produces complementary

divergence of male and female traits, as is exemplified by peacock tails and moose antlers, which are

exhibited only by males. While there are indeed a few highly divergent traits distinguishing women

from men (e.g. patterns of fat deposition in breasts and hips, etc.), the sexes differ only very subtly in

their intellectual and language abilities. Thus accounting for the extravagant complexity of language in

terms of sexual selection requires explaining why it lacks this otherwise ubiquitous mark of extreme

sexual dimorphism. To explain the origin of the highly structured human-unique adaptation inevitably

requires addressing Wallaces challenge concerning the complexity and apparent non-adaptive aspects

of these features.

Long evolution in an artificial niche

In my work I use the phrase, symbolic species, quite literally, to argue that symbols have literally

changed the kind of biological organism we are. I believe that we think and behave in many ways that

are quite odd compared to other species because of the way that language has changed us. In many

respects symbolic language has become a major part of the environment to which we have had to

adapt in order to flourish. In the same way that our ancestors bodies evolved in the context of the

demands posed by bipedal foraging with stone tools and incorporating meat into the diet, their brains

evolved in the context of a rich fabric of symbolic cultural communication. As it became increasingly

important to be able to enter into the social web of protolinguistic and other early forms of symbolic

social communication in order to survive and reproduce, the demands imposed by this artificial niche

would have selectively favored mental capacities that guaranteed successful access to this essential

resource. So rather than merely intelligent or wise (sapient) creatures, we are creatures whose social

and mental capacities have been quite literally shaped by the special demands of communicating with

symbols. And this doesnt just mean that we are adapted for language use, but also for all the many

ancillary mental biases that support reliable access and use of this social resource.

But this claim depends on language-like communication being a long-time feature of hominid

evolution. Theories suggesting that human language is a very recent and suddenly evolvedphenomenon would not make this prediction. To them language is almost epiphenomenal. This is

particularly true if the claim is that language appeared suddenly due to some marvelous accidental

mutation that transformed dumb (but large brained) brutes into articulate speakers. This sort of

scenario has become commonplace in recent years, though the evidence supporting it is mostly very

indirect (e.g. archeological evidence of representational forms and objects for adornment, appearing in

the Upper Paleolithic). I think that it is mostly a reflection of a caricatured view of the human/animal

distinction and a sort of hero metaphor imposed upon the fossil evidence. The way that modern


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human brains accommodate language can be used as a clue to how old language is.

If language is a comparatively recent feature of human social interaction, that is if it is only, say, a

hundred thousand years old or so, then we should expect that it had little effect on human brains. Any

structural tweaks of brain architecture that evolved to support it would have had to be either minimal

or else major but dependent on comparatively few genetic changes. A recent origin of language wouldgive it little opportunity to impose selection pressure on human brains, so language function would not

be supported by any widespread and well integrated neurological changes. This would predict that

language abilities are essentially an evolutionary after-thought, inserted unsystematically into an

otherwise typical (if enlarged) ape brain. With l ittle time for the genetic fixation of many supportive

traits to occur, this adaptation would likely depend on only a few key genetic and neurological

changes. As a consequence, language function should be poorly integrated with other cognitive

functions, relatively fragile if faced with impoverished learning contexts, susceptible to catastrophic

breakdown as a result of certain small but critical genetic defects, and severely affected by congenital

mental impairment.

None of these seems to be the case.

On the other hand, if language has been around for a good deal of our evolutionary past, say a million

years or so, that amount of time would have been adequate for the demands of language to have

affected brain evolution more broadly. A large network of subtle gene changes and neurological

adjustments would be involved, and as a result it should be a remarkably well integrated and robust

neurological function. Indeed, there is ample evidence to suggest that language is both well-integrated

into almost every aspect of our cognitive and social lives, that it utilizes a significant fraction of the

forebrain, and is acquired robustly under even quite difficult social circumstances and neurological

impairment. It is far from fragile.

The co-evolutionary interaction goes both ways. Languages also have to adapt to brains. Since thelanguage one learns has to be passed from generation to generation, the more learnable its structures,

and fitted to human limitations, the more effective its reproduction in each generation. Languages and

brains will evolve in tandem, converging towards each other, though not symmetrically. But brain

evolution is a ponderously slow and unyielding process in comparison to the more facile evolution of

languages. So we should expect that languages are more modified for brains than brains are for

language. Nevertheless, if we have been evolving in a symbolic niche for a million years or more, we

should expect that human brains will have been tweaked in many different ways to aid life in this

virtual world.

The world of symbols is an artificial niche. Its ecology is radically different than the biological niche we

also find ourselves in (or at least our ancestors found themselves in). In the same way that beaver dam

building has created an aquatic niche to which beaver bodies have adapted over their evolutionary

history, our cognitive capacities have adapted to our self-constructed niche: a symbolic niche. This is

not a new idea. Indeed the anthropologist Clifford Geertz suggested something like this many decades

ago. I think that today we may be at a point in our evolutionary theorizing and our understanding of

brains to begin to explore exactly what this might mean.


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The most intense and unusual demands of this niche should be reflected in the ways that human

cognition diverges from patterns more typical of other species. Although it has long been popular to

think of the human difference in terms of general intelligence, I think this bias may have misled us into

ignoring what may be a more important constellation of more subtle differences. These likely included

differences in social cognition (e.g. joint attention, empathy, the ability to anticipate anothers intended

actions), differences in how we learn (e.g. superior transfer learning, a predisposition to assume thatassociations are bidirectionalknown as stimulus equivalence, a comparative ease at mimicking) or

even just unusual motor capacities (e.g. unprecedented articulatory and vocal control). These are

members of a widely distributed and diverse set of adaptations that fractionally and collectively

contribute to our language abilities.

With respect to the brain, we need to confront another mystery. How could these many diverse brain

traits have become so functionally intertwined and interdependent as to provide such a novel means of

communication? This is particularly challenging to explain because language is in effect an emergent

function, not some prior function just requiring fine-tuning. Our various inherited vocalizations, such

as laughter, shrieks of fright, and cries of anguish, are comparatively localized in their neurological

control (mostly subcortical) as are other modes of communication in animals. In comparison, language

depends on a widely dispersed constellation of cortical systems, each of which can be found in other

primate brains, but evolved for very different functions. These brain systems have become collectively

recruited for language only because their previously evolved functions overlapped significantly with

some processing demand necessitated by language, though evolved for quite different functions

altogether. Indeed, the neural structures and circuits involved in the production and comprehension of

language are homologous to structures found ubiquitously in most monkey and ape brains: old

structures performing unprecedented new tricks.

A related mystery concerns the extent to which this dominant form of communication depends on

information maintained by social transmission. Even for theories postulating an innate universalgrammar, the vast quantity and high fidelity of the information constituting even a typical vocabulary

stands out as exceedingly anomalous from a biological point of view. How did such a large fraction of

our communicative capacity wind up offloaded onto social transmission? And what explains the

remarkable reliability of this process?

Relaxed selection and complexity

Perhaps the most surprising and controversial point to be made follows from the realization of the

importance of relaxed selection. The higher-order synergy of systems that contribute to language

requires the cooperative functioning of component brain systems. But it appears to paradoxically

require that this synergy among diverse systems must already be in place in order for selection to havehoned it for language.

The co-evolutionary niche construction scenario sketched above still does not account for the

generation of the novel functional synergy between neural systems that language processing requires.

The discontinuities between call control systems and speech and language control systems of the brain

suggest that a co-evolutionary logic alone is insufficient to explain the shift in substrate. Recent

investigation of a parallel shift in both complexity and neural substrate in birdsong may be able to


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shed some light on this.

In a comparative study of a long-domesticated bird, the Bengalese Finch, and its feral cousin, the

White-Rump Munia, it was discovered that the domesticated lineage was a far more facile song-learner

with a much more complex and flexible song than its wild cousin. This was despite the fact that the

Bengalese Finch was bred in captivity for coloration, not singing (Okanoya, 2004). The domestic/feraldifference of song complexity and song learning in these close finch breeds parallels what is found in

comparisons between species that are song-learners and non-learners. This difference also correlates

with a much more extensive neural control of song in birds that learn a complex and variable song.

The fact that this behavioral and neural complexity can arise spontaneously without specific breeding

for singing is a surprising finding since it is generally assumed that song complexity evolves under the

influence of intense sexual selection. This was, however, blocked by domestication. One intriguing

interpretation is that the relaxation of natural and sexual selection on singing paradoxically was

responsible for its elaboration in this example. In brief, with song becoming irrelevant to species

identification, territorial defense, mate attraction, predator avoidance, and so on, degrading mutations

and existing deleterious alleles affecting the specification of the stereotypic song would not have beenweeded out. The result appears to have been the reduction of innate biases controlling song

production. The domestic song could thus be described as both less constrained and more variable

because it is subject to more kinds of perturbations. But with the specification of song structure no

longer strictly controlled by the primary forebrain motor center (called nucleus RA), other linked brain

systems can begin to play a biasing role. With innate motor biases weakened, auditory experience,

social context, learning biases, and attentional factors could all begin to influence singing. The result is

that the domestic song became more variable, more complicated, and more influenced by social

experience. The usual consequence of relaxed selection is genetic driftincreasing the genetic and

phenotypic variety of a population by allowing random reassortment of allelesbut neurologically,

drift in the genetic control of neural functions should cause constraints to become less specific,generating increased behavioral flexibility and greater conditional sensitivity to other neurological and

contextual factors.

This is relevant to the human case, because a number of features of the human language adaptation

also appear to involve a relaxation of innate constraints allowing multiple other influences besides

fixed links to emotion and immediate context to affect vocalization. Probably the clearest evidence for

this is infant babbling. This unprecedented tendency to freely play with vocal sound production occurs

with minimal innate constraint on what sound can follow what (except for physical constraints on vocal

sound generation). Babbling occurs also in contexts of comparatively low arousal state, whereas

laughter, crying, or shrieking are each produced in comparatively specific high arousal states and with

specific contextual associations. This reduction of innate arousal and contextual constraint on soundproduction, opens the door for numerous other influences to begin to play a role. Like the

domesticated bird, this allows many more brain systems to influence vocal behavior, including socially

acquired auditory experience. In fact, this freedom from constraint is an essential precondition for

being able to correlate learned vocal behaviors with the wide diversity of objects, events, properties,

and relationships language is capable of referring to. It is also a plausible answer to the combinatorial

synergy problem (above) because it demonstrates an evolutionary mechanism that would


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spontaneously result in the emergence of multi-system coordination of neural control over vocal

behavior.

But although an evolutionary de-differentiation process may be a part of the story for human language

adaptation, it is clearly not the whole story. This increased flexibility and conditionality likely exposed

many previously irrelevant interrelationships between brain systems to selection for the newfunctional associations that have emerged. Most of these adaptations remain to be identified.

However, if such a dedifferentiation effect has been involved in our evolution, then scenarios

hypothesizing selection for increased innateness or extrapolation from innate referential calls to words

become less plausible.

Some concluding speculations

In closing, I would like to reflect on some of the more esoteric features of humanness that may be

illuminated by the paired processes of symbolic niche construction effects and relaxed selection.

For example, I think it makes sense to think of ourselves as symbolic savants, unable to suppress the

many predispositions evolved to aid in symbol acquisition, use, and transmission. In order to be so

accomplished at this strange cognitive task, we almost certainly have evolved a predisposition to see

things as symbols, whether they are or not. This is probably manifest in the make-believe of young

children, the way we find meaning in coincidental events, see faces in clouds, are fascinated by art,

charmed by music, and run our lives with respect to dictates presumed to originate from an invisible

spirit world. Like the flight play of birds, the manipulation of objects by monkeys, the attraction of

cats to small feathered toys, our special adaptation is the lens through which we see the world. With it

comes an irrepressible predisposition to seek for a cryptic meaning hiding beneath the surface of

appearances. Almost certainly many of our most distinctive social capacities and biasese.g.

tendencies to conformity and interest in copying the speech we hear as infantsare also reflections of

this adaptation to an ecosystem of symbolic relationships. And of course there is literature and theater.How effortlessly we project ourselves into the experiences of someone else, feeling the joys and

sorrows almost as intensely as our own.

Relaxation of selection, on the other hand, may have contributed to another suite of distinctively

human traits. Widely distributed dedifferentiation at the genetic and epigenetic level would have

increased flexibility of a variety of once phylogenetically constrained cognitive and motivational

systems. Perhaps the most striking feature of humans is their flexibility and cultural variety. Consider

the incredible diversity of marital and kinship organizations. Most species have fairly predictable

patterns of sexual association, kin association, and offspring care, and although they are somewhat

flexible, this variety is mediated almost entirely by individual motivational systems. In contrast,

despite the evolutionary importance of reproduction, human mating and reproduction are largely

controlled by symbolically mediated social negotiations. This offloading of one of the most

fundamental biological functions onto social-symbolic mechanisms is perhaps the signature feature of

being a symbolic species. Thus, because of symbols and with the aid of symbols, Homo sapiens has

been self-domesticated and adapted to a niche unlike any other that ever has existed. We have been

made in the image of the word.


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References

Darwin C (1859) On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races

in the Struggle for Life(John Murray, London), 1st Ed.

Darwin C (1860) Letter 2743 Darwin, C. R. to Gray, Asa, 3 Apr 1860. Source: http://

www.darwinproject.ac.uk/entry-2743.

Darwin C (1871) The Descent of Man and Selection in Relation to Sex (John Murray, London).

Deacon TW (1997) The Symbolic Species: the Coevolution of Language and the Brain(W. W. Norton & Co.,

New York).

Deacon TW (2009) Relaxed selection and the role of epigenesis in the evolution of language. Oxford

Handbook of Developmental Behavioral Neuroscienceeds Blumberg MS, Freeman JH, Robinson SR (Oxford

University Press; New York) pp 730-752.

Lyell C (1863) Geological Evidences of the Antiquity of Man(John Murray, London).

Okanoya K (2004) The Bengalese Finch: A window on the behavioral neurobiology of birdsong syntax . Annals

NY Acad Sci 1016:724735.

Wallace AR (1869) Sir Charles Lyell on Geological Climates and the Origin of Species. Quarterly Review,

April, cxxvi: 359-94.

30 comments to On the Human: Rethinking the natural

selection of human language

Mark Turner

February 15th, 2010 at 3:17 am

Terry Deacon hits the nail on the head in urging us to reconsider the interaction between natural

selection and human language. His emphasis on long evolution is apt. His focus on relaxed

selection in an artificial niche is original, potentially seminal. He offers here a major extension

of his proposals in The Symbolic Specieswhich I reviewed favorably when it was first published

(see http://ssrn.com/author=1058129 ).My disagreement with Deacon is captured in his title: The Natural Selection of Human

Language. There was no natural selection of human language per se, independent of other

advanced abilities. Rather, the basic mental capacity for conceptual integration, otherwise known

as blending, has been evolving since the mammalian line. Human beings evolved a more

advanced ability for blending. This advance made it possible for several related behaviors to

arise as a suite of coordinated and mutually-supporting products of blending. Human language

was one of them. Gilles Fauconnier and I made this proposal in The Way We Think(Basic Books,


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2002; see http://markturner.org/wwt.html).

Evolutionary accounts often take their cue from a rough-and-ready list of advanced human

behaviors we see all about usadvanced music, advanced social cognition, culture, religion, sign

systems, gesture, language, art, science, advanced dance, fashion, advanced tool use, math, . . .

and then, considering them metaphorically as independent traits, seek an evolutionary story for

each, regardless of the others. What most needs to be reconsidered is that impulse. To the extentthat we are able to interrogate the archeological record, these behaviors seem to be recent and to

have come up in concert. To the extent that we are able to study these behaviors in living human

beings, they appear to develop in concert. Blending theory proposes that these behaviors

cooperate because they are siblings, drawing on the same mental source.

Consider surfing. Its an amazing behavior, highly complicated, creative, demanding. Its

Polynesian invention is, evolutionarily speaking, very recent, and its development and

proliferation have occurred mostly in my lifetime. (Fins are a recent invention; the leash was

invented when I was in college.) No one imagines that there has been natural selection for this

behavior per se. Pushing the timeframe back a little, consider writing. Writing is at most 8000

years old. Writing as we know it is at most only a few thousand years old, and writing as acommon activity is at most only a few hundred years old. No one imagines that there has been

natural selection for this behavior per se. Push this back to fifty, sixty, seventy thousand years or

so. I propose that instead of remarkably simultaneous independent evolution or coevolution of

all these different advanced behaviors, there was long evolution of the enabling mental ability,

which reached a crucial tipping point. From that tipping point, all these products arose and

coevolved. The suite was highly adaptive, and the result was cognitively modern human beings.

Derek BickertonFebruary 15th, 2010 at 4:21 pm

Both Terry Deacon and Mark Taylor focus on how language evolved once it had appeared, but

they have little to say about its initial emergence. (Marks remark that Human beings evolved a

more advanced ability for blending leaves a host of questions unansweredhow did it evolve;

why did it evolve in the way it did in humans; why, if it was so common, didnt it evolve in the

same way in other species; and on and on.) Relaxed selection is a good ideaI already pointed

out in Adams Tongue that language could not emerge until communication had broken its link

with fitnessbut it can only apply AFTER a trait is present; after all, Bengal finches could sing

even before domestication. What nobody in the field of language evolution (or in evolution

generally) seems to realize is the extent to which the very notion of being able to use an arbitrarysign to symbolize entities or actions in the real world is totally alien to the way other animals

think. No explanation of how language evolved can be viable unless it first faces this problem

and then explains how it was overcome.


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Mark TurnerFebruary 16th, 2010 at 3:21 am

Derek: Blending theory addresses directly the initial emergence of language. Chapter-

length arguments by Fauconnier and Turner are available in The Way We Think:

Conceptual Blending and the Minds Hidden Complexities, Basic Books, 2002; and The

Origin of Language as a Product of the Evolution of Modern Cognition in Laks,Bernard, et al., editors, Origin and Evolution of Languages: Approaches, Models,

Paradigms. London: Equinox, 2008. There is also a very brief 2008 Fauconnier & Turner

BBS commentary, The Origin of Language as a Product of the Evolution of Double-

Scope Blending.

Alf Hornborg

February 16th, 2010 at 7:24 am

Deacons reasoning beautifully transcends the dichotomy of human versus natural sciences by

accounting for both the multiplicity of human experience and its biological conditions. I am in

complete sympathy with the argument as a whole, but would like to add a few suggestions on

how it could be expanded. First, the distinction between artificial and biological niche may not be

as significant as Deacon proposes, if we accept Uexklls conclusion that all species inhabit

subjective worlds defined by their particular capacities to process signs. Not only do different

species navigate environments defined by their specific perspectives (a circumstance recognized

by many indigenous peoples and reported by anthropologists from Hallowell to Viveiros de

Castro), but the same of course applies to human cultures. As Sahlins and others have shown,

there is no unmediated, objective world accessible to humans. Even for our ancestors, any

biological niche would have been ethno-biological, whether linguistically codified or not. Second,

the proposal that the relaxation of natural and sexual selection has been conducive to linguistic

and cultural diversity wonderfully harmonizes with ecological theories on the creative

proliferation associated with biological colonization of new and less competitive habitats. The

relaxation of constraints appears to encourage creativity in both contexts. Finally, having spent

years trying to grasp the significance of kin terminologies, I think Deacons argument could more

explicitly make the point that the operation of such terminologies, in defining potential spouses,

is not only a reflection of cultural diversity unleashed by the relaxation of selective constraints

but recursively also a source of such relaxation. In the co-evolutionary process that he has

identified, language has relaxed selective pressures by delegating reproductive success to social

conventions. If the relaxation of selection is an explanation of language, the opposite is equallytrue.

Derek BickertonFebruary 17th, 2010 at 2:41 am


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Mark, none of your chapters seem to be available on the web, so I cant comment specifically on

your proposal within the time-frame of this discussion. For now Ill just say that my position is

diametrically opposed to yours, since I believe that enhanced cognition comes from language,

rather than vice versa. I take it that your position excludes any task-specific mental mechanisms

for language, a position which my own work on creole languages renders implausible (although

please note I do NOT endorse Chomskys version, or versions). However, I would reallywelcome a chance to pursue this discussion (I am not among those who automatically rule out

any opinion contrary to their own), so if you have available electronic versions of any of the

three articles you cite, could you send them to me at ?

Lorenzo MagnaniFebruary 17th, 2010 at 5:26 am

I would like to add a few suggestions on how to extend this wonderful analysis of language as a

cognitive niche given by Deacon. It would be interesting taking advantage of this framework

to address the problem of the intertwining between language and cooperation, to increase

knowledge about an important topic: violence. Here the example of fallacies. The hypotheses

generated by the so-called fallacies in a dialectic interplay (but also when addressed to a non-

interactive audience) are certainly conflict-makers but they do not have to be conceived

absolutely as a priori deal-breakers and dialogue-breakers. I would contend that the

potential deceptive and uncooperative aim of fallacies can be intertwined with pieces of both

information and disinformation, logical valid and invalid inferences, other typical mistakes of

reasoning like perceptual errors, faulty memories and misinterpreted or wrongly transmitted

evidence, but fallacious argumentations still can be at first sight paradoxically civil ways/

conventions for negotiating. That is, sending a so-called deceptive fallacy to a listener is much

less violent than sending a bullet, even if it can enter as violent linguistic behavior a further

causal chain of possibly more violent results. Also in the case of potentially deceptive/

uncooperative fallacious argumentation addressed to a non-interactive audience, the listener is

in principle in the condition to disagree with and reject what is proposed (as in the case of

deceptive and fallacious advertising or political and religious propaganda). In summary,

language is possibly a tool exactly like a knife, as Ren Thom already contended some decades

ago.

Terrence DeaconFebruary 18th, 2010 at 9:57 pm

On the Mark Turner / Derek Bickerton debate:

I am in sympathy with Derek Bickerton in treating the capacity to use conventional symbolic

reference as a more fundamental (and simpler) threshold distinguishing recent hominid

evolution. I have been arguing this point since the early 1990s. Moreover, it should be obvious


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that our ability to utilize symbolic tools has greatly facilitated conceptual blending. But I also

recognize that the notion of conceptual blending may also extend to domains beyond symbolic

processes, though this fact doesnt make this process more basic. But I worry that conceptual

blend theory needs more unpacking. It is too abstract in its current cognitive science incarnation,

and needs to be decomposed into component neural processing dynamics so that it isnt treated

like some monolithic function that is present or absent. In service of this goal I think we needto consider it along side its earlier close cousins: i.e. the related notions of Arthur Koestlers

bisociation Gregory Batesons double description Charles Pierces abduction and

extensive abstraction. I actually think that there could be a useful collective unpacking of all

five concepts to get at some of the underlying process assumptions, on the way to a unified

cognitive neuroscience theory. But the either/or framing of this issue is counter-productive.

These capacities co-evolved. As cognitive supports for each evolved and were socially developed

they reciprocally amplified each other. We are good double-scope blenders because we can tap

into vast symbolic supports and analogues, and we can develop remarkably rich symbolic

systems because we can create complex conceptual synergies via conceptual blending. Again we

need to approach this issue from a synergistic co-evolutionary perspective, which is a coreassumption of the target piece. This view implies that both symbolic-linguistic and blending

capacities evolved in tandem. At an early phase of this evolutionary ratchet I suspect that the two

capacities are not differentiable from one another and so a chicken and egg debate may be

pointless. More to the point, I think that both capacities require similar neurological

augmentation, particularly involving prefrontal cortical functions (e.g. enhancement of transfer

learning, combinatorial working memory, displacement of intrinsic salience/reward effects,

stimulus equivalence bias). These are phylogenetically atypical cognitive capacities. The question I

address here is how this suite of interdependent capacities relevant to language and symbolic

cognition evolved to its present state. Relaxed selection effects are particularly relevant to this

debate. De-differentiation is a prerequisite to both the interaction of the relevant neurological

systems and the ability to juxtapose divergent cognitive processes as required by both symbolic

reference construction and cognitive blending.


I am grateful to Mark Turner for kindly making available to me electronic versions of two of the

items he cited in his second post on this thread. They made for fascinating reading, and I

certainly wouldnt dream of questioning the centrality of conceptual blending in all aspects ofmodern human cognition, including language. But the centrality of something now does not

automatically entail its centrality then, and from my perspective, conceptual blending does not

explain how language evolved.

Before I start, however, a sincere word of apology to Terry. Much of what I shall say has only an

oblique bearing on Terrys case (although I am here in a sense arguing against him, since I do

believe that natural selection, albeit in a bizarre and indirect way, did cause language to evolve).

Be it noted however, that my thinking on this is and has been for the last few years heavily


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influenced by my (somewhat tardy) acceptance of Terrys contention that symbolism, not syntax,

is the major defining mark of the human species. And I do accept that, once language had begun

to evolve, long evolution in an artificial niche is about as good a capsule description of what

took place as youre likely to get. The question I want to zero in on is, Was natural selection

responsible for starting language?

Marks case in many ways resembles Terrys, but to my great surprise, it is also in many wayssimilar to Chomskys. I know this sounds counterintuitive, but note the following:

1) Neither account makes substantive reference to pre-human evolution..

2) Both accounts root human-prehuman discontinuity in thought rather than behavior.

3) Both accounts implicitly assume that the cognitive/conceptual system of human predecessors

was similar to that of humans.

4) Both accounts assume that the internal revolution that made language possible was fully

completed before the utterance of a single word.

5) Both accounts assume that language emerged quite abruptly and substantially in the form in

which we find it today; in other words, they assume that there was nothing intermediate

between an alingual state and modern human languageno kind of protolanguage that did notalready have all the major properties of modern human language.

In fact, the only significant difference between the two models seems to be that the engines

driving them were in the one case syntactic (the process Merge) and in the other semantic

(conceptual blending).

Reverting to (1), above, although Mark claimed in his first post to this thread that the basic

mental capacity for conceptual integration, otherwise known as blending, has been evolving since

the mammalian line, at the beginning of Chapter 9 of The Way We Think he states that the

considerable efforts of animal psychologists have uncovered no evidence that other species can

reach very far in conceiving of counterfactual scenarios (like those underlying pretense),

metaphors, analogies, or category extension. These statements seem to me flatly contradictory,

and if the second is correct, what caused the explosion of blending capacity in a single mammal?

He asserts (without giving details) that each step of the [blending] capacity would have been

adaptive because each step gives existing cognitive ability to compress, remember, reason,

categorize and analogize. But he gives no evidence of any evolutionary results from this

increased capacity. I agree that the fact that conceptual blending IS so complex and far-reaching

suggests that it must have had some evolutionary history. But this fact is equally consistent with

the view that conceptual blending began (and could only have begun) once the first overt

symbolic units (call them words, proto-words, word-like objects or whatever you want) came

into existence perhaps a couple of million years ago. And the latter view is indeed more

consistent with the large cognitive gap that, as Mark admits, exists between humans and other

animals.

T. Givn

February 19th, 2010 at 4:44 pm

Terry Deacon certainly opened a beautiful can of worms, elegantly and provocatively, but it is


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still a can of worms. For what he says to make sense, considerable filling-in is required. Since

brevity is demanded by the venue, I apologize for the extreme compression of what follows.

1. Complexity and relaxed selection: There is an unfortunate tho no-doubt unintended inference

here that a highly complex system, with a lot of cross-modular interaction and co-evolution,

necessarily transcends adaptive selection. Such an inference is dubious in biology, where its most

ardent proponents are the ID crowd. It is equally dubious when it comes to language. Plenty ofrun-of-the-mill cellular, somatic, and neurological systems are highly complex but still

unimpeachably adaptive, selected and genetically coded. By itself, systemic complexity does not

translate into relaxed selection. Rather, it points out to more a complex, interactive, multi-

factored selection. Epiphenomena or spandrels may be one consequence of complex selection,

but they are hardly counter-evidence to it. Human language is a prime example of a highly

complex multi-modular system that is nonetheless adaptive and selected. And the presumed

arbitrariness and extravagance of its spandrels is vastly over-stated.

2. Innateness, variability and selection: In general, the older a system is in bio-evolution, the

more rigidly-programmed (innate) it tends to be in the genome. Older evolved systems exhibit

more within-species uniformity, are more fully automated at birth, and are less sensitive toepigenesis, maturation and learning. In contrast, more recently evolved systems tend to be less

rigidly programmed in the genome, exhibit more phenotypic and behavioral variability, and are

more susceptible to maturation and learning effects. But this flexibility and variability of recently

evolved systems is hardly evidence for relaxed selectional pressures. On the contrary, such

variability and behavioral flexibility are the innovative vanguard of adaptive selection (Mayr

1976, 1982; Fernald & White 2000, West-Eberhard 2003). Through the interaction of niche

construction and genetic assimilation, flexible behavioral experimentation eventually becomes

assimilated into the genome (Baldwin 1898; Waddington 1942, 1953; West-Eberhard 2003). In

principle, phenotypic and behavioral variability in the early stages of evolutionary change is a

highly adaptive phenomenon. It allows for multiple adaptive solutions to compete head on,

before selection pares the multiplicity down to the few that have proven themselves over

multiple generations and contexts. These success stories are then coded more rigidly in the

genome. The progression from old (reptile) brain to mid-brain to cortex is a terrific example of

this evolutionary trend, with decreased genetic specification, increased phenotypic and

behavioral variability, and increased maturation-and-learning sensitivity.

3. Cognition vs. communication: I must confess I find the Turner-Bickerton exchange here rather

unenlightening. On the one hand, the neurological systems that underlie pre-human and pre-

linguistic cognitionof objects-and-events, of somatic sense and motor control, of space-and-time,

of action and agencyare ancient mammalian and pre-mammalian systems (Ungerleider and

Miskin 1982; inter alia). Not only do they predate human communication by a wide margin, they

also serve as the platform upon which the more elaborate cognitive representation system thatunderlies human language was erected. True, language has prompted a great elaboration,

complexity, and increased abstraction of its precursor representational systems. But the core

neurological sub-systems that underlie language processing arose much earlier and still perform

many of their pre-linguistic functions (Amunts et al. 1999; Bookheimer 2002; Badre and Wagner

2007; Kaan 2009; Hagoort 2009; Fiederichi 2009; Friederici & Brauer 2009; Fernndez-Duque 2009;

inter alia).


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On the other hand, to suggestas so-called cognitive linguists are fond of doing that somehow

the communicative apparatus of human language and in particular grammar falls out of the

cognitive representational system is to ignore both what grammar does as an adaptive system

and how uniquely it is structured; as well as to ignore the distinct, complex, multi-modular

neurology of grammar (Friederici 2009, inter alia). Communication is not mental representation.

Rather, it is the transfer of mental representations from one mind to another. It certainlypresupposes mental representation, but does not fall out of it.

4. Diversity vs. universality: Human language, as a relatively recent and highly complex

adaptation (from ca. 1.8 million to ca. 100,00 years ago) bears all the marks of a recently-evolved

biological system: Flexibility, maturation-and-learning dependence, and considerable phenotypic

and behavioral variability. It is too tempting, however, to over-state linguistic variability and

ignore the great amount of universality of language functions, structures and controlling

principles. Just as it is too tempting from the opposite perspective to exaggerate universality and

pooh-pooh variability (Chomsky 1992; Hauser et al. 2002). From my middle-ground vantage

point, I see plenty of universals of both phonological and grammatical structure and function.

Like all good species-specific universals, they surely are genetically coded. Still, such universalallow considerably phenotypic and behavioral variation, and such variation is biologically natural

functionalgiven the complexity and evolutionary recency of human language.

5. The adaptive niche of human language: To understand the difference between pre-human and

human communication, one must begins with two core features of non-human communication: (a)

non-displaced reference; and (b) strictly manipulative speech-acts.

The first feature indeed predicts the second: When communication is only about here-and-now,

you-and-I, this-and-that visible in the shared speech-situation, there is no need for declarative

speech-acts. All relevant information (epistemics) is fully shared. Only manipulation (deontics)

needs to be communicated. Humans are the only species that, overwhelmingly, communicates

about displaced reference by transacting declarative and interrogative speech-acts. The adaptive

niche for human communication must have, therefore, entailed some vital information that is not

available in the here-and-now but rather pertains to there-and-then, and is therefore not shared

equally by speaker and hearer. Several possible niches qualify for this condition: (a) reporting on

and recruitment for cooperative foraging of remote food-sources (big-game hunting, Washburn

& Lancaster 1968; big-game scavenging, Bickerton 2009). (b) reporting on and planning for

migration to a remote new territory; (c) reporting on and planning for hostile engagement

elsewhere. All three ecological niches are unique to the hominid line. All three demand

declarative/interrogative communication about remote referents. Is it an accident that the two

adaptive niches in which honey bees developed their symbolic communication are: (a) reporting

on and recruitment for foraging of a remote food-source; and (b) reporting on and recruitment

for migration to a remote new hive-site (von Frisch 1967; Gould and Towne 1987)?6. Human language as a complex adaptation: Saying that human communication is symbolic is

saying relatively little. The devil is in the extremely complex detail. Human language has two

distinct codesphonology and grammarthat perform different functions and evolved at

different times. Phonologythe sound codeis much more concrete, arbitrary (symbolic) and

easier to get a grip on. It functions primarily to code the lexicon of entities (nouns), events

(verbs) and states (adjectives); that is, to code semantic memory. All the available evidence


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suggests that phonology evolved much earlier, giving rise first to pre-grammatical pidgin (Givn

1979, 2009) or proto-language (Bickerton 1981, 2009). But while seemingly a lexical code, single-

word symbols in actual communication do not code mere lexical information, but rather

propositional speech-acts. Thus the vervet monkeys predator calls (Cheney and Seyfarth 1990)

do not code the merely-lexical eagle, leopard, snake, but rather the propositional speech-acts

hide from the eagle, watch out for the leopard, run from the snake.Grammar evolved much later and gradually, and is much more complex and abstract. Its

adaptive motivation is much harder to understand, due primarily to out-of-context

contemplation of structures detached from their adaptive contexts (Chomsky 1965). Once

grammars adaptive-communicative function is understood, it turns out to be much less arbitrary

than the sound code. Grammar encodes multiple, highly specific communicative functions, most

of them having to do with the speakers assessment of the hearers deontic (intention) and

epistemic (belief) mental states during ongoing communication. It is a highly-automated

instrument for representing other minds (Givn 2005), much more efficient and less error-prone

than pre-grammatical pidgin. Not only is grammar as a whole adaptive, but specific grammatical

construction perform specific communicative functions, in a way that is highly constrained andfar from arbitrary (Haiman ed. 1985; Givn 1995, 2001, 2005). The familiar story of grammar as

an extravagant spandrel (e.g. Hauser et al. 2002) thus needs to be tempered with the

understanding of grammars adaptive function.

References:

Amunts, K., A. Schleicer, U. Burgel, H. Mohlberg, H.B.M. Uyling and K. Zilles (1999) Brocas

region re-visited: Cytoarchitecture and intersubject variability, J. of Comparative Neurology,

421.1

Badre, D. and A.D. Wagner (2007) The left ventrolateral prefrontal cortex and the cognitive

control of memory, Neuropsychologia, 45

Baldwin, J.M. (1896) A new factor in evolution, The American Naturalist, 30

Bickerton, D. (1981) Roots of Language, Ann Arbor, MI: Karoma

Bickerton, D. (2009) Adams Tongue, NY: Hill and Wang

Bookheimer, S. (2002) Functional MRI of language: New approaches to understanding the

cortical organization of semantic processing, Annual Review of Neuroscience, 25

Cheney, D. and R. Seyfarth (1990) How Monkeys See the World, Chicago: University of Chicago

Press

Chomsky, N. (1965) Aspects of the Theory of Syntax, Cambridge, MA: MIT Press

Chomsky, N. (1992) A minimalist program for linguistic theory, MIT Occasional Papers in

Linguistics, , Cambridge, MA: MIT Press

Fernald, R.D. and S.A. White (2000) Social control of brains: From behavior to genes in M.

Gazzaniga (ed. ) The New Cognitive Science, 2nd edition, Cambridge, MA: MIT PressFernndez-Duque, D. (2009) Cognitive and neural underpinnings of syntactic complexity, in T.

Givn and M. Shibatani (eds) Syntactic Complexity, TSL #85, Amsterdam: J. Benjamins

Friederici, A. (2009) Brain circuits of syntax, in D. Bickerton and E. Szathmry (eds) Biological

Foundations and Origin of Syntax, Cambridge, MA: MIT Press

Friederici, A. and J. Brauer (2009) Syntactic complexity in the brain, in T. Givn and M.

Shibatani (eds) Syntactic Complexity, TSL #85, Amsterdam: J. Benjamins


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Givn, T. (1979) On Understanding Grammar, NY: Academic Press

Givn, T. (1995) Functionalism and Grammar, Amsterdam: J. Benjamins

Givn, T. (2001) Syntax: An Introduction (2 vols), Amsterdam: J. Benjamins

Givn, T. (2005) Context as Other Minds, Amsterdam: J. Benjamins

Givn, T. (2009) The Genesis of Syntactic Complexity, Amsterdam: J. Benjamins

Gould, J.L. and W. Towne (1987) Evolution of the dance language, The American Naturalist,130.3

Hagoort, P. (2009) Reflections on the neurobiology of syntax, in D. Bickerton and E. Szathmry

(eds) Biological Foundations and Origin of Syntax, Cambridge, MA: MIT Press

Haiman, J. (ed. 1985) Iconicity in Syntax, TSL #6, Amsterdam: J. Benjamins

Hauser, M., N. Chomsky and W.T. Fitch (2002) The faculty of language: What it is, who has it,

how did it evolve? Science, 298

Kaan, E. (2009) Fundamental syntactic phenomena and their putative relation to the brain, in D.

Bickerton and E. Szathmry (eds) Biological Foundations and Origin of Syntax, Cambridge, MA:

MIT Press

Mayr, E. (1976) Evolution and the Diversity of Life, Cambridge, MA: Harvard University PressMayr, E. (1982) The Growth of Biological Thought, Cambridge, MA: Harvard University Press

Ungerleider, L.A. and M. Mishkin (1982) Two cortical visual systems, in D.G. Inge, M.A,

Goodale and R.J.Q,. Mansfield (eds) Analysis of Visual Behavior, Cambridge, MA: MIT Press

von Frisch, K. (1967) The Dance Language and Orientation of Bees, Cambridge, MA: Harvard

University Press

Waddington, C.H. (1942) Canalization of development and the inheritance of acquired

characters, Nature, 150

Waddington, C.H. (1953) Genetic assimilation of an acquire character, Evolution, 7

Washburn, S.L. and C. Lancaster (1968) The Evolution of Hunting, in R.B. Lee and I. DeVore,

Man the Hunter, Chicago: Aldine

West-Eberhard, M.J. (2003) Developmental Plasticity and Evolution, Oxford: Oxford University

Press


Terry, when I hear words like bisociation, double description, or abduction, I reach for my

Occams razor. Aside from that, I think were (mostly) on the same page. Both symbolic-

linguistic and blending capacities evolved in tandem. Right on! After that our difference ismerely one of focus. You are, as you say, concerned with their subsequent evolution, while I am

concerned with how they got started in the first place. Which was hen and which was egg, or

was it a third party? Something had to get the whole thing started, but people dont seem to see

that this is the real problemjust about anything can evolve further once its gotten startedso

they either ignore it or give the kind of answer that shows they havent really thought it

through.


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At this point, there is far too much in Tom Givons response for me to even contemplateresponding to, except to say to all involved that you shouldnt assume that I have said

everything that I wanted to say about this issue in the 2500 word essay that I have contributed.

In order to stay within the size limitations of this venue I only opened a narrow window on the

relationship between natural selection and language, and even at that I could only hint at the

details. This inevitably has led Tom to conclude that just because I have emphasized one

previously unappreciated aspect of the problem (self-organization effects intrinsic to epigenetic

processes and the way that they are exposed via niche-construction) that I am denying the

importance of the other (natural selection on biological substrates to generate functional

correspondences). Far from it.

For the most part we are in agreement on many points, and perhaps in a later post I can address

a few of the ways we diverge. Here I only comment on the general points made about natural

selection. There is a much larger biological background behind my approach which of necessity

has had to go unmentioned. It traces to my work on brain development and evolution, and more

broadly it borrows from work that currently runs under the banner of evodevo and which has

begun to illuminate once problematic issues in evolutionary genetics, molecular cellular biology,

and epigenesis. My point is not to discount the contributions of natural selection, which I agree is

the final arbiter of functional adaptation, but to bring attention to another unnoticed facet of the

evolutionary process. Natural selection is explicitly NOT the generator of the biological

phenomena that it prunes in the process that leads to increased adaptation. Not only are the

variants of existing organismic subsystems generated irrespective of function (e.g. by genetic

damage) but the expression of these varieties of structure and dynamics depends on generative

processes whose details we tend to hide in generic concepts like epigenesis and reproduction.

New stuff, new structures, and new processes need to be generated so that there is raw material

fed to the engine of natural selection. The second law of thermodynamics has to be locally tamed

in order for this to be possible. And natural selection theory is so widely applicable precisely

because it can be agnostic as to how any of this is achieved, so long as it is. Surprisingly, despite

our many disagreements about innateness, I find some resonance in Noam Chomskys periodic

suggestion that some of the complexity of grammar may have emerged from general laws of

physics analogous to the way that the Fibonacci regularities exemplified in the spirals of

sunflower seed and pine cone facets emerge. Natural selection has found a way to stabilize the

conditions that support the generation of this marvelous regularity of growth because it hasimportant functional advantages. But natural selection didnt generate it in the first place,

geometric regularities that can become amplified due to center-out growth process are the

ultimate source (as has now been demonstrated also in growth-like inorganic processes). I also

agree that flexibility CAN be an adaptive response to a variable and demanding habitat, but not

necessarily. And I hope I have shown that there is another mechanism potentially available to

explain some of the complexity (both neurologically and functionally) and some of the flexibility,

besides natural selection and innate algorithms. In this essay, I am only interested in pointing out


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the importance of processes that have tended to be overlooked by those assuming that only

natural selection in its most basic sense is at work, and that any universals must be assumed to

arise from genetic origin. Just appealing to genetic accident is little better than invoking a

miracle.

Indeed, this is a can of worms, and like Pandoras box, even just opening it a crack runs the risk

of unleashing explosion of linked conceptual problems. Derek (and Mark), dont be too sure thatyou can ignore the various theories related to conceptual blending. I do think that buried in this

mess is an important insight into the crucial transition that we both find so interesting. I am

happy to welcome Occam into the game but I am wary of trying to simplify too soon, and as a

biologist I am constantly confronted with the fact that mother nature doesnt respect this razor.

This goes for restricting our explanations to simplifying assumptions about natural selection,

mechanisms contributing to biological complexity, theories attempting to explain the source of

language universals, and how we account for the neurological teaks that provide us with such a

distinctive capacity.

In response to my remarks suggesting that I am only interested in the subsequent evolution of

language capacities, I meant this only in the context of the present essay. Indeed, Derek and Iagree that explaining the transition from non-symbolic to symbolic communication is ground

zero.


Your last paragraph is well said, Terry, but when it comes to ground zero, what seems to you the

role of natural selection there? After all, any reader faced with your bare title might have

expected to hear something about that.


Ground zero:

I still stand by the general scenario as sketched in my book The Symbolic Species, in which I

argue that the shift in foraging ecology precipitated by the development of the first stone tool

technology at 2.4 million years ago was the first spark. This was a first niche construction activity,that embedded these early hominids in a radically different ecology and demanded a

fundamental restructuring of social-sexual relationships that only symbolic communication

(because of its displacement of reference) could stabilize. Indeed, I dont believe that stone tool

supported foraging could have been maintained across generations without it. The meager

capacity of great apes to acquire a very small repertoire of symbolic signs (with highly structured

support) suggests to me that the cognitive flexibility of these australopithecine (A. garhi) tool

users was just barely sufficient to achieve this level of symbolization (probably mostly in the form


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of ritualized performances). But this created a complex synergy between tool technology and

communicative technology that could only be sustained by social transmission. This semiotic

niche is the hominid equivalent to a beaver dam. It both relaxed selection on many traits no

longer critical, and shifted selection onto others, specifically those that would support the

stability of this virtual niche. Cognitive flexibility niche construction shifted selection and

relaxed selection shifted cognitive predispositions and increased cognitive flexibility Myanswer to your question, then, is that neither natural selection nor some lucky genetic accident

precipitated this transition. It was cognitive flexibility and the social capacity to acquire novel

behaviors by observation learning.


Terry, I agree with everything you say, but you still arent getting to grips with the real crux of

the matter, which is, how and why were the first symbolic signs created? Ive said it before, Ill

say it again, if it comes to that, YOUVE said itthe idea of using a sound or gesture to symbolize

a concept of some real-world entity is something totally alien to non-human minds. Some kind of

ritual doesnt begin to explain things, because nothing in a ritual necessitates having a concept of

anything. For instance a chimps rain dance could develop into some kind of ritual, getting more

complicated over time, without it symbolizing anythingits just what they do when raindrops

keep falling on their heads. For all the many virtues of The Symbolic Species, it did not, unless

memory fools me, contain any explicit account of how the first words, manual signs or whatever

came to be.

Slawomir Wacewicz

February 20th, 2010 at 11:18 pm

Full twenty years after the publication of the Pinker-Bloom BBS paper that many see as

foundational for the entire field of evolution of language, it is very interesting to see a text by

Prof. Deacon on the same general topic the role of natural selection but reaching a novel and

provocative conclusion. When Pinker and Bloom argued for a specific role of natural selection in

designing subsystems of the human language faculty, Deacon points to the possible role of the

relaxation of selection pressures in (phylogenetic) language development. However, the textstarts with alluding to many important points regarding the evolution of language let me start

from enumerating these points (of, I hope, consensus) because they are well worth re-

emphasizing:

1. Language itself must have been a selection pressure humans as a species (thus, their

cognition) show clear signs of having been selected for efficient language use.

2. The language-brain coevolution, as suggested by the name, is CO-evolution, so it works in

both directions: language evolves to adapt to its environment, i.e. the human brain/mind. This


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idea has been especially prominent in the works of M. Christiansen.

3. Before there was full language there must have been a simpler communication system, but

already distinguished by the use of arbitrary and conventional signs, > symbols. This of course

is a development on D. Bickertons seminal idea of protolanguage.

4. Language (or protolanguage) couldnt have developed from nothing as it were, bare ape

cognition but instead must have been built upon a rich collection of cognitive preadaptationsfor language, such as Theory of Mind (further subdivisible into joint attention, empathy, etc.),

mimesis, and many others. Prof. Bickerton comments on this in discussion.

5. Language, or at least protolanguage, is something phylogenetically old. 50kY [50,000 year]

theories of language origin are deeply problematic. It is symptomatic that the idea of a very

recent emergence of language seems to be popular with very many researchers with a passing

interest in this field, but only very few researchers with more that a passing knowledge (e.g.

seasoned Evolang delegates). For many years Deacon has been consistent in his criticisms of the

50kY theories.

I can offer little in the way of commenting on the novel argument concerning the possible effect

of the relaxation of selection pressures, but I would like to venture two questions.1. One important (indeed, crucial, but often neglected) feature is missing from the explanation

and that is the transfer of honest information (already alluded to by Prof. Givn). What language

accomplishes is essentially *altruistic* transfer of honest information to nonrelatives how could

an altruistic form of behaviour have evolved certainly is non-obvious and requires an

explanation.

Could your account perhaps be made compatible with some particular explanation of the

emergence of altruism/cooperation as manifested in linguistic communication?

2. As it stands, relaxation is a rather general concept: the removal or subsiding of what *specific*

selection pressures should be subsumed under this term in the present context?

Finally, this is probably a good opportunity for thanking Prof. Deacon for his presentation at the

Protolang conference in Torun last year a big thank you once again!

Slawomir Wacewicz

Salikoko S. Mufwene

February 21st, 2010 at 2:09 pm

Terrence Deacon has written a thought-provoking article on the co-evolution of language and the

brain, from the perspective of niche construction. He submits an evolutionary account that

conjures up an adaptive/exaptive perspective that in some ways conflicts with the language thathe uses to explain it, for instance when he says that we are creatures whose social and mental

capacities have been quite literally shaped by the special demands of communicating with

symbols and modern brains accommodate language, as well as by his characterization of the

social niche in which language evolved as artificial. It all sounds as if symbolic and cultural

communication had origins separate from and/or independent of the brain and hominin social

interactions, worst of all an existence that is anterior to the state of the hominin brain that could

use it. Therefore the brain would have been adapting to language rather than language reflecting


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what the brain is capable of. Selection would have operated through the survival, at different

stages of the phylogeny of mankind, of those hominins whose brains could accommodate the

complex structures and functions of then-emergent languages all the way to modern ones.

The scenario as presented sounds contrary to what one would expect to have happened. A

comparison with other animal species suggests that hominins had always been able to

communicate, albeit in less complex ways at earlier stages of our phylogeny; evolution has led usto gradually develop more and more complex systems for communication (based on

predominantly symbolic devices built upon more elemental phonetic/signed units and

combinatorial conventions). Part of the complexity itself must have emerged from the

interactions of modules that produced various strategies at different times. It is thus also

plausible to conceive of languages as emergent phenomena (see below).

I think it is relevant to consider the fact that parrots can imitate speech, though the anatomical

structure they use is different from that of humans. Thus the particular shape of humans bucco-

pharyngeal structure is secondary compared to the role of our minds. The reason why parrots

cannot produce novel utterances that they have never heard before (which characterizes

linguistic competence), thus cannot use speech creatively, is that they are not endowed with thekinds of minds that can behave linguistically in the human style. This appears to be the same

reason why they have not capitalized on their potential to produce phonetic sounds to develop a

human-like communicative system for themselves. It is likewise significant that great apes have

not developed signed languages of their own (though they have forelimbs similar to humans)

nor any complex social cultures comparable to humans, among other things that distinguish them

from mankind. The 2% or so of genetic materials they do not share with humans include the

absence of the kind of mental capacity that modern humans are endowed with.

It seems to me that human languages (spoken and signed) reflect the complexity of the minds

that produced and use them, and in fact have continued to reshape them to date, although

perhaps in respects evolutionarily less significant than those associated with the protracted

emergence of language. An account that sounds plausible would involve hominins adaptive

quest for more and more suitable means of communication as their minds evolved toward

increasingly more complex structures/activities and they produced more and more complex

social life styles and organizations that called for more and more sophisticated modes of

communication. Such a scenario would account for the emergence of symbolic communication

and culture. Even if these evolved rather later in the phylogeny of mankind, they would still

typify humans as a unique symbolic species unlike any other in the animal kingdom.

I think it is important to underscore the fact that communication with any means, apparently in a

form more holistic than combinatorial, occurred much earlier. A challenge we face is to explain

the transition from holistic vocalizations and gestures to compositional speech and signed

language, respectively, with hierarchically-structured discrete units. (Linguists should think hereof double articulation, though reality suggests more levels!) None of this evolution would have

been possible without the emergence, after the separation of the Homo line from the other

primates, of mental structures capable of domesticating the human anatomy to meet new and

more complex communicative needs. Language may have enhanced human cognition, in fact it

facilitates its ontogenetic development (thanks to its world-creating capacity), but comparisons

with other animals suggest that the hominin ability to think and solve problems differently from


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other primates seems to have preceded the emergence of symbolic language itself.

The question of how diversity emerged would be more puzzling if the cradle of mankind had

lain in one single camp or village in East Africa and language had been designed. Linguistic

systems have been so resistant to reductions to a few regularities largely because they consist of

phenomena that emerged at different times in response to specific communicative needs, with the

innovations being only partly constrained by current strategies. In a nutshell, we must bear inmind that any kind of cultural evolution has involved innovators and copiers, with these roles

varying with every feature. If, as I assume, there were different hominin colonies not bound to

meet their communicative needs in identical ways, and if innovators in the same colonies could

produce alternative responses to the same or similar challenges, then the question should be not

why there is variation (both language-internal and cross-linguistic) but why there is not more

typological variation than would be possible. The answers need not lie in the monogenesis of

language. They probably lie in the kinds of species-specific evolutionary factors (physiological

and mental) that constrained the languages (at any evolutionary stage) that different populations

produced. Note that Language is the invention of the scholar, a useful generalization indeed,

but not a phylogenetic singular suggested by the geographical distribution of the availablepaleontological evidence. These considerations lead us to the question of what the language

organ or Universal Grammar proposed in theoretical linguistics means and what it really

consists of, if such a device need be posited.

Leigh Van ValenFebruary 21st, 2010 at 4:24 pm

Yes, interesting, and I look forward to a more fleshed-out version. There is also the possibility of

selection specifically for a relaxation of constraints, not mit einem Schlag but a progressive

loosening of a relatively more closed behavioral system in a prelinguistic or protolinguistic

context of more flexible overall behavior. Ostensive identification or protodefinition would seem

to require such capacity.

Such a process, like relaxation of selection (from what initial state?), gives complexity, and

perhaps a less disordered complexity. Constraints would be relaxed in a way that enhances

function, an outcome that is less expected under the random dissociations that would be

produced by drift under relaxed selection.

Results of active selection along the open-closed continuum are well known in the context of

learning and fixed action patterns. The active selection I suggest here would operate on the same

connections that Deacon envisages.An aside: Language evolution, in recorded cases, often proceeds partly by structural

simplification, making the language easier to learn and the overall trend thus advantageous.

There is then the obvious question of how the earlier complexity arose. This complexity doesnt

follow from the relaxation of constraints, which merely permits it. Many languages with few or

no speakers today are remarkably complex, in different ways. Might the size of isolated small

groups somehow promote complexity? There may be a correlation here, but an actual causal

process seems mysterious.


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Derek Bickerton

February 21st, 2010 at 4:56 pmSlawomir Wacewicz has asked an excellent question, one which every language evolutionist

should be prepared to answer: why should anyone transfer useful information to non-kin (and

why should non-kin believe themthe cheap tokens problem!)? It seems to me that for these

objections to be overcome, at least the following four conditions should hold:

1) Speaker gains an immediate benefit from giving the information (not just some possible future

reciprocity).

2) Speaker can only obtain this benefit if the information is given.

3) Speaker can derive no benefit from giving the information if it is false.

4) Hearer can quickly verify whether the information is false or not.

I know of only one situation in which all these conditions can be met. Around 2 million years

ago, human ancestors began to engage in scavenging megafauna carcasses. In order to exploit

such carcasses and cope with a fearsome array of competitors, those ancestors were obliged to

gather large (> 50) groups. To do so they would have had to inform conspecifics of the nature

and whereabouts of those carcasseswithout adequate numbers, the operation could not be

carried out and no-one would benefit. Note that with this scenario, you solve at one blow the

evolution not just of language but of co-operationthe only other major dimension on which we

differ from our primate kin. For a detailed account, see chapters 4-8 of Adams Tongue.

Derek BickertonFebruary 21st, 2010 at 6:51 pm

Leigh van Valens aside: Lee, Im afraid youre confusing language evolution with linguistic

change. Since modern homo, languages have been cycling around within the relatively narrow

search space provided by the mature language faculty. If a language is used by a small

homogeneous community for a long time undisturbed, it will accrete complexities like a ship

accretes barnacles. If a language undergoes severe social disturbances or gets to be used by large

numbers of people, it will shed those complexities. I think thats one of the few things few

linguists would quarrel about.

Sara WallerFebruary 23rd, 2010 at 1:05 pm

Thanks so much for this enlightening discussion, and thanks to Mark Turner especially for letting

me know about it. I think Ive missed the deadline for a response any chance for an extension


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of continuation? It would be fun to talk more about animal communication, language, and human

thought.

Gary Comstock

February 23rd, 2010 at 1:56 pm

While the discussion will remain open until Terry posts his final reply, we cannot guarantee

that he will have seen comments posted after Feb. 24.

Sue Savage-RumbaughFebruary 24th, 2010 at 12:35 pm

The exchanges in this dialogue are fueled by a desire to understand how language could have

evolved from something that appears to be not language, and by a firm belief that language sets

humanity apart from other living beings on the planet. Most of the participants agree that only

human beings possess language, and most agree with Terry that symboling (not grammar) is the

key event in hominid evolution the Ground Zero. Some continue to view the gestures and

vocalizations of other animals as symbolic but holistic in nature. Some continue to assert that

combining symbols is a truly unique human innovation and that Terrys emphasis on symbols is

misguided. I would like to set that debate aside for now, due to lack of space. For those who

wish to know, my view is that true symboling and grammar are inextricably intertwined. It is

fundamentally impossible to have one without the other and previous attempts to view them as

separable has misled humanity in its search for a solution to the origins of language.More important for the current debate however, is the fact that this debate began before science

achieved the ability to rapidly sequence the entire genome and to follow genes across

generations. Such new data is challenging the ground rules of evolutionary theory at its core. We

no longer need infer that genes have changed, because anatomy and behavior have changed. We

can look and see if genes have changed and what genes have changed. We now know the

following things.

a) The biggest genetic differences between apes and human beings lie in genes that code for

immunity not those that code for intelligence or language in any simple sense, or anatomy. Apes

and humans are true sibling species.

b) The onset of FLUENT speech could indeed have been a sudden genetic event. This is differentfrom the onset of speech itself, or the linkage of speech to a wide array of complex cognitive

processes.

c) Epigenetic markers are more likely than genes themselves to account for the behavioral

changes we associate with language, thus making the ape to human transition more of a cultural

transformation than a biological transformation.

d) Genetic activation profiles during prenatal and postnatal development, as a function of culture,

can manifest differently in different environments, with major life changing consequences.


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The basic question of whether evolutionary theory can account for language must now be

understood on the basis of this new knowledge.

Ape rearing requires clinging, human rearing does not. Thus the ape and human developmental

trajectories that are built from birth forward, produce different kinds of beings and very

different epigenetic profiles. This one difference, clinging, affects the tendency toward

bipedalism, toward free vocalization, and toward object use and manufacture.When bonobo infants are reared in an environment which decreases or eliminates the constant

need to cling to the mother, their hands and eyes become free from birth to engage in a variety

of object manipulatory activities. This allows the brain to construct eye/hand/mouth/object

manipulatory systems that are co-ordinated in ways that follow the pattern of human infants.

The need to cling inhibits this and channels the neurological development of eye/hand

coordination in a non-relaxed developmental manner. This phenomenon is analogous to

Deacons relaxation hypothesis, but it is the culture which is the relaxing constraint, not the

genes. Not only do patterns of eye/hand coordination change in striking ways with human

rearing, the vocal system becomes relaxed as well. This is not because it becomes free of any

genetic constraint. It is freed because of a decrease in the risk of predation. Humans infantsliving in stable dwellings are far less likely to be attacked than bonobo infants. When an bonobo

infant, in an arboreal a world, gets very far away, makes very much noise or gets interested in

playing with objects rather than watching its mother and rushing to her before she moves, its

chances of survival decrease markedly. If a bonobo mother puts a very young baby down, it is

immediately subject to predation. Human reared bonobo infants face no such pressure and are

free, because of human culture, to follow the developmental trajectory of the human infant.

As they do so the plasticity of their nervous systems allows them to process and comprehend

human speech, both symbols and syntax. Thus it becomes clear that the ground zero question

does not apply to whether apes have language ability they do. The question is what is the

cultural trajectory required to facilitate a human language. The answer is that the required

cultural trajectory is obviously a human one. Were a human child to be reared along an ape

cultural trajectory, even though it had a human brain, it would not manifest a human language,

even though it possessed a human brain and would, like free-ranging apes, manifest the ability to

communicate symbolic meaning with intentionality.

While some linguists continue to quibble about whether what Kanzi has demonstrated is really

exactly human language, this debate is really no longer relevant. Kanzi clearly has acquired

sufficient language ability to indicate that the human rearing trajectory is the key ingredient in

the emergence of human language. In this vein, it is essential to note that Kanzi did not have a

uniquely human rearing he was reared in a Pan/Homo culture. Had Kanzi been reared with a

uniquely human trajectory, his human language capacity would perhaps have become sufficiently

well developed that not only would he be producing vocal approximations of human words andsentences, but quite clear ones. (For those readers interested in seeing what Kanzi and family

have accomplished, go to Kanzi.bvu.edu)

Kanzi is a first generation attempt to determine what happens when scientific investigation

p

on the human- rethinking the natural selection of human language by terrence w. deacon

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