Tomasello, Michael;
Origins of human communication
MIT Press, 2008, 400 pages [gbook]
ISBN 0262201771, 9780262201773
topics: | language-acquisition | cognitive | primate | communication | intention | phylogeny
Tomasello's views on how human language differs from animal communication has been evolving in recent years, and this latest instalment contains considerable material that is novel, and is of great interest for those interested in issues of language evolution, phylogenetic (native) structures needed for language, and particularly the question of language acquisition. Even in his relatively recent work, such as the 2005 book on Constructing a Language: A Usage-based Theory of Language Acquisition, what distinguishes human from animal communication was posited in terms of two features - that linguistic communication is symbolic, and that it is grammatical: Human linguistic communication differs from the communication of other animal species in two main ways. First, and most importantly, human linguistic communication is symbolic. Linguistic symbols are social conventions... The second main difference is that human linguistic communication is grammatical. Human beings use their linguistic symbols together in patterned ways, and these patterns, known as linguistic constructions, take on meanings of their own — deriving partly from the meanings of the individual symbols but, over time, at least partly from the pattern itself. ... (p.8) Personally, I am not so sure about the second point (grammaticality) - why is animal language non-grammatical? One can surely posit a rudimentary grammar for many animal interactions (e.g. growl is likely to precede attack; the bee's dance), whether they are conventional or not. The bee dance may be thought of as quite a product of a systematic process, a grammar. A much more subbstantial argument originally posited by Chomsky, that the grammar for human language is recursive, has been weakened by evidence that humans are poor at more than a few (say three) levels of recursion, and any finitely recursive system can also be modeled using non-recursive grammars. Also, there is no evidence for recursion at other levels of language such as phonology. Many erstwhile Chomskyans have given up on the recursion-only hypothesis (e.g. see Pinker and Jackendoff, The faculty of language: what's special about it? in Cognition, Mar 2005). But clearly, human language is qualitatively different from animal communication; and Tomasello has been chipping away at the arguments that remain in this quest to define human uniqueness. We see in his 2005 argument re: grammar that like most cognitive linguists, Tomasello views grammar as a meaning-carrying structure, both for animals and us. Other points emphasized by Tomasello include "shared intentionality" - while it turns out that primates have some degree of intentional interpretation to signals (e.g. they lie) - there appears to be no evidence of joint attention or intentionality, which is a clear pre-requisite for the kinds of social interactions leading to language. Two years later, in the Handbook of child psychology, (eds. William Damon; Richard M. Lerner etal 2006), Tomasello in his article on "Acquiring linguistic constructions" (chapter 6), edits the text from 2005 to include a third distinction. Human linguistic communication differs from the communication of other animal species in three main ways. First, and most importantly ... [text is identical to CaL for two paragraphs] Third, unlike all other animal species, humans do not have a single system of comm used by all members of the species. Rather, different groups of humans have conventionalized over historical time diff, mutually unintelligible systems ... more than 6K natural lgs in the world. This means that children must learn the communicative conventions used by those around them... While this is clearly an important distinction, it is far from novel. It doesn't help answer the question of what makes it possible for human infants to acquire language (say sign language) whereas other species cannot. In this important new text, Tomasello argues for yet another distinction - that humans are phylogenetically co-operative, so that the pragmatic nature of communication is present only in humans. Among the evidence he marshals towards this argument are some startling data in the second chapter, where he shows that while chimpanzees have pointing gestures, they cannot grasp the fact that the act of pointing is intended as an helpful signal. Thus, a chimp who is hungry and searching for food may have a human caretaker point towards a box, and he may even go to that box, but instead of turning over that box, he may try some other one. What the chimp does not perceive, says Tomasello, is that human communication is intended to be helpful for the other - language is, in essence, a co-operative activity. Gestures among chimpanzees, on the other hand, is essentially an attention-seeking mechanism, not intended to be helpful. Where this argument is a little weak is that once a chimp is with other humans, they also use referential gestures (pointing to hidden food, requesting humans to retrieve it, etc.). But such gestures are apparently not used among themselves. In other animal communications, e.g. the well-known vocabulary of vervet monkeys, it seems that the vervet calls are not intended to be a signal at all. That they provide it under specific circumstances, and that others understand it as such, and other species sharing the area may even learn it as a signal, but the signal is instinctive, a sort of behavioral module, and not intended to be helpful. Macaques have a "predator" alarm call, but in experiments, they do not give it when they see a predator approaching their offspring; it is elicited only when they themselves are at risk [Cheney/Sefarth:1990b]. p.18: In all, this pattern of flexible comprehension but totally inflexible production in primate vocalizations is captured nicely by Seyfarth and Cheney, Listeners acquire information from signalers who do not, in the human sense, intend to provide it. [S/C 2003:168] [Seyfarth and pioneers in primate signalling] The inability of most animals to recognize the mental states of others distinguishes animal communication most clearly from human language. - [Signalers and receivers in animal communication, Ann. rev psych, v.54:1, 2003] : This claim was novel for me, and it opens up new horizons in our understanding of language. One radical possibility that struck me is that perhaps it is pragmatics that we are genetically programmed for, and given the semantics (after most grammatical categories such as nouns or verbs or gender or tense are just as good as semantic categories) - the syntax is learned using the same (domain-independent) mechanisms as are used in learning to categorize the world visually, say. This is followed up by further details on how this is put into effect by babies acquiring a language. For example, babies learn to take turns well before they learn language; the grammar of taking turns may be more usefully thought of as learning pragmatics; certainly it has little to do with syntax. Tomasello demonstrates how this turn taking behaviour is key to further advances in learning symbols (phonological units and their semantic mappings) and finally combinations of these symbols (syntax, where larger strings also constitute a form-to-semantics mapping) This book is based on Tomasello's Jean Nicod Lectures in Paris, 2006.
understanding of the call is quite flexible - "Impressively, indivs of a
num of monkey species may even learn during ontogeny to use the alarm calls
of other species, incl some birds, to obtain info abt nearby predators
[Zuberbuehler 2000].
In stark contrast to this flexible comprehension, monkeys and apes do not
learn to produce their vocal calls at all, and have very little voluntary
control over them. ([Tomasello and Zuberbuehler 2002]: reiew) 16
- stimulus for vocalization is tightly fixed, cannot adapt to communicative
situation
- human attempts to teach vocalizations invariably fail
- however, one aspect is flexible - they do not call if alone or without
kin. 17
tight binding of vocalizations may be because they are tied to emotional
states.
The production of sound in the absence of the appropriate emotional
state seems to be an almost impossible task for a chimpanzee.
[Goodall 1986:125]
Tellingly, when macaque mothers in experiments see a "predator" approaching
their offspring, they do not give an alarm call so long as they themselves
are not at risk (Cheney/S:1990b).
Also, vervets often persist in the signal when all the audience are in safe
positions looking at the predator. 19
Sometimes chimps give "pant-hoots" upon finding food even if the whole group
is there and eating [Clark-wrangham-94, though see mitani-nnishida-93].
In all, this pattern of flexible comprehension but totally
inflexible production in primate vocalizations is captured nicely by
Seyfarth and Cheney,
Listeners acquire information from signalers who do
not, in the human sense, intend to provide it. [S/C 2003:168]
[Seyfarth and Cheney are pioneers in primate signalling]
Nonhuman primates vocalize in response to important events, irresp of how
potential recipients may view the situation. [Zuberbuhler 2005 p.126]
on this basis argues that these vocalizations are simply signals, and
qualitatively v different and unrelated to human lg.
two types: intention-movements / attention-getters
chimpanzees :
INTENTION-MOVEMENTS:
arm-raise = initiate play
touch-back (by infants to moms) = request being carried [start of
climbing on]
hand-beg: place hand under Recip's mouth = request food
[start of taking food)
head-bob: bobs and weaves in bowing position = initiate play
arm-on : place arm on recipient's back = start tandem walk
[start of dragging into walk]
ATTENTION-GETTERS:
ground-slap: slap on ground and look at R = often, play
poke-at : a body part of R = various
throw-stuff: at r = often, play
hand-clap: slap own wrist, while approaching R = often, play
back-offer: insistently put own back in front of R = typically grooming
table, p. 23
unlearned intention-movements (first steps of a behav sequence) are
uniquitous in the animal kingdom (noted by [Darwin 1872]), and
systematically described by [Tinbergen 1951] in his classic studies of
seagulls.
such behav have evolved phylogenetically - i.e. they confer some advantage -
e.g. wolves baring fangs and growling - other retreats; or birds signalling
impending sexual advances during mating. 22
ontogenetically learned signals - are more flexibly used - e.g. arm raise for
initiating play. these are always the first part of the action.
ontogenetically ritualized gesture:
these intention-movement signals are abbrevs of full social actions - almost
always dyadic (single recipient). Learned by initially using raising arm and
then hitting and jumping on - over repeated instances, this is understood as
a signal for impending rough & tumble play, then the signaler waits after the
arm-raise for a response 24
--> [ICONIC ? Tomasello doesn't think so p.26-7]
[evidence for this mechanism of learning - and not imitation p.25-6]
attention getters - not widespread at all - may be even unique to primates or
even great apes.
but again, these are learned by repeatedly successfully gaining attention by
doing these actions ... 29
60-70% of gestures of captive chimpanzees : "pointing" to out-of-reach food so the human will retrieve it for them. Behav arise spontaneously without any training from the humans [Leavens-Hopkins-98,LH-bard-05]. Typically, they are doing this through a cage, and so they orient their body toward the out-of-reach food, and thrust their fingers and hands through the caging toward the food as well. - p.35 Pointing is used flexibly - if several types of food are avlbl, apes will point to the most desirable one, and will continue pointing to it even if given a less desirable food [lbh-05]. when they observe that a human needs a tool to retrieve food for them, and the tool is hidden while the human is away, when the human returns, they will point to the location of the hidden tool [call-tomasello-94]. This is still best seen as a req that the human retrieve the tool (so he can retr the food) because apes do not gesture in this situation if the tool is for the human's own use. chimps raised in rich human contexts, similar to the way human children are raised, have been obsrvd to req things imperatively in other ways as well. E.g point to a locked door reqsting human to open it - or will lead the human to the door or high shelf by pulling his hand, stopping and waiting in front of it expectantly [gomez 90]. May also bring a recalcitrant object (e.g a locked box) to human for help. Apes in zoos often develop attn getters from visitors, eg. clapping hands - so they may throw food. Often look at the eyes of the human while making such requests - suggests they know that the causality/ intentionality somehow emanates from behind the eyes and not just from the external limbs carrying out the desired actions [Gomez 90, 2004] 37 These pointing gestures are a natural extension of their own attention-getting gestures. Obv q.: why apes point for humans, but not for one another? obv answer: other apes are not motivated to help them in the same way as humans. 37 evolutionary implication: if social env of apes suddenly became more cooperative, they could point imperatively to req help from each other w no other addl cogn machinery. 37 no ape, neither to ape or human audiences, uses pointing to serve functions other than the imperative. Do not point declaratively to simply share interest, or to inform abt something the other may want or need to know, as human infants do right from very early in ontogeny (see ch 4). [tomasello-carpenter-05] presented 3 young human-raised chimps with situations that reliably elicit expressive-declarative pointing in human infants (e.g. surprising, interesting, events), but observed no declaratives from them. 38 Also, even the signed productions of "linguistic" apes are almost all imperatives - approx 96-98% in the only two systematic studies [Rivas 05, Greenfield/savage-rumbaugh-90].
[tomasello-call-gluckman-97]:
introduced apes to a game in which one human, the hider, hid food in one
of three buckets and a second human, the helper, helped them to find it -
what has been called the object choice task. Apes knew from prev
experience that there was only one piece of food and they wd get only one
choice. In the key exptl condition, the hider hid the food from the ape
while the helper peeked, and then the helper simply pointed informatively
for the ape to the bucket in which the food was hidden. Astoundingly,
apes then chose buckets randomly, even though they were highly motivated
to find food on almost every trial. Quite often they followed the
helpers' pointing and looking to the correct buckedt, but then did not
choose it. Thus, following the directionality of the point was not the
problem; they just did not seem to understand its meaning, its relevance
to their search for food.
It is as if the apes said to themselves "OK. There's a bucket. So what?
Where's the food?" Human infants perform well on this seemingly trivial
task by 14 mos (behne-carpenter-tomasello-2005).39
hare-tomasello-2004: previous basic choice task, plus a competitive task, in
which a human is competing w ape for food.
without looking at the ape in any way, the human reached toward the
correct bucket, but because her arm could not go very far through the
plexiglas hole, was unable to reach it. [on the ape's turn] it knew where
the food was! 40
thus they read the human intentionality behind the reaching gesture as a sign
that the human may be expecting food in this bucket. but they fail to
understand in the other situation that the human is communicating
altruistically in order to help them towards their goals. 41
but dogs do very well in the basic choice tasks. wolves do poorly. most
animals that do well have been raised by humans - dogs, trained dolphins,
domestic goats, and a few hand-raised chimps. as for dogs, perhaps humans, as
they were domesticating dogs, selected (over the past 10K to 12K years) for
individuals w characteristics enabling them to understand the human intention
(in some sense). but research is still on-going. 43
it is diff to appreciate the astounding [nature of] apes' flexible skills of gestural communication. The vast majority of animal comm is basically genetically fixed... though gestural comm of monkeys have not been studied in much in much detail, it appears mostly stereotypic [maestripieri-1998]. the flexibility of great ape gestural comm is thus truly an evolutionary novelty. behavrl flexibility is generally a sign that learning is involved and indeed we presented evidence that many ape gestures are learned. But this could, in theory, be either rel simple assoc learning -- or complex cognitive processes involving an understanding of the intentionality of the communicn partner. We bel that complex cogn processes are involved... [next section]
- when human passes food to chimp, and then fails to do so, ape reacts w frustration as if h is deliberately unwilling - whereas she waits patiently if h is making good-faith attempts that are failing accidentally [call-etal-04; behne-etal-05 w human infants] - when human or conspecific needs help in reaching, chimps help in manner sim to human infants - requires understanding of the other's goal [warneken-tomasello-06, warneken-07] - shown an action that is marked as a failed attempt to do X (eg hands slipping off the object); chimp in her turn does X and not the action actually demo'd. [tomasello-carpenter-05, based on meltzoff-95 w h infants] - when a human shows a human-raised chimp a series of two actions on an object, one of which is marked as accidental, the ape usually executes only the intended action [tomasello-carpenter-05, based on carpenter-akhtar-tomasello-1998 study on human infants] 45 - human-raised chimp understands diff between actions that are freely chosen vs forced. only former is imitated [buttelmann-etal-07, based on gergely-bekkering-kiraly-02 study on h infants]
- when h peers behind a barrier, ape moves over to get a better view and to look behiind as well. - when h's gaze is directed toward a barrier and there is also an object beyond it, ape look only to barrier and not at object, unless barrier has a window in it, when they look at object. - when apes beg for food, they take into acct whether h can see the gesture - when chimp compete w each other for food, take into acct whether the competitor can see the contested food, and even on occasion attempt to conceal their approach from a competitor. 48 chimps understand that - agents want certain states to obtain (have goals) - agents see the world and so can assess the situation w r t the goal state - agents do things to when they perceive that the environment is not in the goal state. this kind of understanding of intentional action supports a basic form of practical reasoning that enables indivs to understand and predict what others are doing and will do, even in novel situations. The vast majority of studies on nonhuman primate comm focus on vocal displays, without even mentioning gestures (two recent exceptions are corballis-02 and burling-05). This is a huge mistake - primate vocal dispalys are no diff from other mammals - mostly unlearned, genetically fixed, emotionally urgent, involuntary, inflexible. in contrast, a signific num of great ape gestures are learned and flexibly produced.
opening quote: I wouldn't know what I should point to in the picture as a correlate of the word kiss... or... the word taller... [But] there is an act of "directing attention to the size of people" or to their actions... This shows how it was possible for the general concept of meaning to come about. - Wittgenstein, The big typescript
1 A Focus on Infrastructure 1 a very general intro of 12 pages - is avlbl at http://mitpress.mit.edu/books/chapters/0262201771chap1.pdf 2 Primate Intentional Communication 13 3 Human Cooperative Communication 57 4 Ontogenetic Origins 109 5 Phylogenetic Origins 169 6 The Grammatical Dimension 243 7 From Ape Gestures to Human Language 319 References 347 Author Index 373 Subject Index 379
Human communication is grounded in fundamentally cooperative, even shared, intentions. In this original and provocative account of the evolutionary origins of human communication, Michael Tomasello connects the fundamentally cooperative structure of human communication (initially discovered by Paul Grice) to the especially cooperative structure of human (as opposed to other primate) social interaction. Tomasello argues that human cooperative communication rests on a psychological infrastructure of shared intentionality (joint attention, common ground), evolved originally for collaboration and culture more generally. The basic motives of the infrastructure are helping and sharing: humans communicate to request help, inform others of things helpfully, and share attitudes as a way of bonding within the cultural group. These cooperative motives each created different functional pressures for conventionalizing grammatical constructions. Requesting help in the immediate you-and-me and here-and-now, for example, required very little grammar, but informing and sharing required increasingly complex grammatical devices. Drawing on empirical research into gestural and vocal communication by great apes and human infants (much of it conducted by his own research team), Tomasello argues further that humans' cooperative communication emerged first in the natural gestures of pointing and pantomiming. Conventional communication, first gestural and then vocal, evolved only after humans already possessed these natural gestures and their shared intentionality infrastructure along with skills of cultural learning for creating and passing along jointly understood communicative conventions. Challenging the Chomskian view that linguistic knowledge is innate, Tomasello proposes instead that the most fundamental aspects of uniquely human communication are biological adaptations for cooperative social interaction in general and that the purely linguistic dimensions of human communication are cultural conventions and constructions created by and passed along within particular cultural groups.
by Michael C. Corballis, Jan 2009 Just seven years after the publication of Darwin's Origin of Species in 1859 the Linguistic Society of Paris famously banned all discussion of the origins of language. The ban was reiterated in 1872 by the Philological Society of London. It seems to have persisted; a century later, Noam Chomsky declared it ‘a serious error’ to suppose that language could be explained in terms of natural selection [1]. The study of language was largely confined to a linguistic cocoon, and language was assumed to be uniquely human, the product of some saltational event, be it a genetic mutation or the fortuitous outcome of an increase in brain size. [saltation: mutation that drastically changes the phenotype] ... No longer is language the exclusive preserve of the linguists, and even Chomsky's influence seems to be waning quickly. Michael Tomasello is one of the pioneers of the change. His new book, Origins of Human Communication, summarizes his ground-breaking work on cognition and communication in chimpanzees and in human infants, and creates an evolutionary and developmental scenario in which language emerges, not from animal calls or vocalizations, but from manual gestures. The prerequisites for language, he argues, lie in intentionality and theory of mind. Ever since Premack and Woodruff [3] raised the question in 1978, there has been dispute as to whether chimpanzees possess theory of mind. Tomasello argues that they do, but only to the extent of understanding the intentions of others. This restricts their communications to attention-getting and requests. Human language requires further recursive steps to allow shared intentionality (i.e. ‘not only do I know what you are thinking but I also know that you know that I know this’). This leads to the Gricean concept of language as a cooperative enterprise that goes beyond requesting to informing and sharing knowledge. Although chimps do not seem capable of shared intention, Tomasello finds evidence for it in the pointing behaviour of human infants from the age of about 1 year. In human development, as in evolution, the bases for language are evident in manual gesture, whether it then proceeds to sign language or to speech. Language then unfolds, not through the mystical workings of universal grammar, but through conventions that arise in cultural contexts. Although true language remains beyond the grasp of non-human species, its development can be understood in naturalistic terms. Tomasello's argument is impressive for its subtlety and depth, but it has narrow confines. At one point he notes that human communication is crafted for reference to events that are not perceptually present, and much of our conversations have to do with the sharing of past events or imagined future ones, or indeed fictional ones. Thus, another spur to the evolution of language – and grammar – could have been the ability to travel mentally in time [4]. Whether this is unique to humans, however, remains a matter of contention. [unfortunate that] Tomasello cites evidence that the FOXP2 gene came to fixation no more than 150 000 years ago. He means a mutation of the gene, not the gene itself, but the dating of the mutation has been questioned by evidence that it was present in Neandertal DNA, suggesting that it goes back some 300 000 to 400 000 years [5]. But this in turn has been disputed [6], so the FOXP2 mutation could well signal the fact that autonomous speech came late to our species, and was long preceded by a communication system that was predominantly manual. Surprisingly, there is no mention of mirror neurons, which often feature in accounts of language evolution. Although mirror neurons have been too freely invoked to explain a wide range of phenomena, they do offer strong support for the view that language evolved from a system in the primate brain that has to do with manual grasping [7]. Has the idea that language originated in manual gestures finally come of age? It arose in the 18th century and was intermittently advocated in the ensuing centuries. It appeared in modern form in an article by Hewes [8] in 1973, and several authors, including myself [9], have tried to update and elaborate it since then. For the most complete and up-to-date account, readers might well read Tomasello's fine book in conjunction with the recent books by Rizzolatti and Sinigaglia [7] and Armstrong and Wilcox [10]. These three books take very different routes, but come to essentially the same conclusion. References 1 N. Chomsky, Reflections on Language, Pantheon (1975) p.59. 2 S. Pinker and P. Bloom, Natural language and natural selection, Behav. Brain Sci. 13 (1990), pp. 707–784. 3 D. Premack and G. Woodruff, Does the chimpanzee have a theory of mind?, Behav. Brain Sci. 1 (1978), pp. 515–526. 4 T. Suddendorf and M.C. Corballis, The evolution of foresight: what is mental time travel, and is it unique to humans? Behav, Brain Sci. 30 (2007), pp. 299–351. 5 J. Krause et al., The derived FOXP2 variant of modern humans was shared with Neandertals, Curr. Biol. 17 (2007), pp. 1908–1912. 6 G. Coop et al., The timing of selection of the human FOXP2 gene, Mol. Biol. Evol. 25 (2008), pp. 1257–1259. 7 G. Rizzolatti and C. Sinigaglia, Mirrors in the Brain, Oxford University Press (2008). 8 G.W. Hewes, Primate communication and the gestural origins of language, Curr. Anthropol. 14 (1973), pp. 5–24. 9 M.C. Corballis, From Hand to Mouth: the Origins of Language, Princeton University Press (2002). 10 D.F. Armstrong and S.E. Wilcox, The Gestural Origin of Language, Oxford University Press (2007).