1. Language
We’ve already covered language a bit already. A good example of language recursion is given by children’s rhymes, such as This is the House That Jack Built:
It is a cumulative tale that does not tell the story of Jack’s house, or even of Jack who built the house, but instead shows how the house is indirectly linked to other things and people, and through this method tells the story of “The man all tattered and torn”, and the “Maiden all forlorn”, as well as other smaller events, showing how these are interlinked…(Wikipedia)
“The House That Jack Built” plays on the process of embedding in English noun phrases. The nursery rhyme is one sentence that continuously grows by embedding more and more relative clauses as postmodifiers in the noun phrase that ends the sentence…In theory, we could go on forever because language relies so heavily on embedding.
The Noun Phrase (Papyr.com)
In English, clauses can be embedded either in the center, or at the end:
In “The House That Jack Built” clauses are added to the right. This is called right-embedding. Much more psychologically taxing is so-called center-embedding, where clauses are inserted in the middle of clauses. We can cope with a single embedded clauses as in:
“The malt that the the rat ate lay in the house that Jack built.”
But it becomes progressively more difficult as we add further embedded clauses:
“The malt[that the rat (that the cat killed) ate] lay in the house that Jack built.”
Or worse:
“The malt [that the rat (that the cat {that the dog chased} killed) ate] lay in the house that Jack built.
I added brackets in the last two examples that may help you see the embeddings, but even so they’re increasingly difficult to unpack. Center-embedding is difficult because words to be linked are separated by the embedded clauses; in the last example above, it was the malt that lay in the house, but the words malt and lay are separated by twelve words. In holding the word malt in mind in order to hear what happened to it, one must also deal with separations between rat and ate and between cat and killed…Center embeddings are more common in written language than in spoken language, perhaps because when language is written you can keep it in front of you indefinitely while you try to figure out the meaning….The linguistic rules that underlie our language faculty can create utterances that are potentially, if not actually, unbounded in potential length and variety. These rules are as pure and beautiful as mathematics…
The Truth About Language pp. 13-14
Or a song you may have sung when you were a child: “There Was an Old Lady who Swallowed a Fly.”
The song tells the nonsensical story of an old woman who swallows increasingly large animals, each to catch the previously swallowed animal, but dies after swallowing a horse. The humour of the song stems from the absurdity that the woman is able to inexplicably and impossibly swallow animals of preposterous sizes without dying, suggesting that she is both superhuman and immortal; however, the addition of a horse is finally enough to kill her. Her inability to survive after swallowing the horse is an event that abruptly and unexpectedly applies real-world logic to the song, directly contradicting her formerly established logic-defying animal-swallowing capability. (Wikipedia)
The structure can be expressed this way:
cow [goat (dog {cat [bird (spider {fly})]})] – after which, she swallows the horse and expires. The resulting autopsy would no doubt unfold a chain of events resembling a Matryoshka doll (or a Turducken).
Or yet another chestnut from my childhood: “There’s a Hole in My Bucket,” which is less an example of recursion that a kind of strange loop:
The song describes a deadlock situation: Henry has a leaky bucket, and Liza tells him to repair it. To fix the leaky bucket, he needs straw. To cut the straw, he needs an axe. To sharpen the axe, he needs to wet the sharpening stone. To wet the stone, he needs water. But to fetch water, he needs the bucket, which has a hole in it. (Wikipedia)
Whether all human languages have a recursive structure by default, or are at least capable of it, is one of the most controversial topics in linguistics.
Bringing more data to language debate (MIT News)
The idea that language is not just based on external stimulus, but is in some way “hard-wired” into the human brain was first developed by Noam Chomsky. He argued that this meant that grammatical constructions were somehow based on the brain’s inner workings (i.e. how the brain formulates thoughts internally), and therefore all languages would exhibit similar underlying structures, something which he called the “Universal Grammar.”
Furthermore, he argued that language construction at its most fundamental level could be reduced to a single recursive operation he called Merge. This was part of his so-called “Minimalist Program” of language construction.
Merge is…when two syntactic objects are combined to form a new syntactic unit (a set).
Merge also has the property of recursion in that it may apply to its own output: the objects combined by Merge are either lexical items or sets that were themselves formed by Merge.
This recursive property of Merge has been claimed to be a fundamental characteristic that distinguishes language from other cognitive faculties. As Noam Chomsky (1999) puts it, Merge is “an indispensable operation of a recursive system … which takes two syntactic objects A and B and forms the new object G={A,B}” (Wikipedia)
The Merge applies to I-language, the thinking behind language, whereas the language spoken out loud is translated into what he calls E-Language (E for external). Corballis explains:
The Merge operation…strictly hold for what Chomsky calls I-language, which is the internal language of thought, and need not apply directly to E-language, which is external language as actually spoken or signed. In mapping I-language to E-language, various supplementary principles are needed. For instance…the merging of ‘Jane loves John’ with ‘Jane flies airplanes’ to get, ‘Jane, who flies airplanes, loves John’ requires extra rules to introduce the word who and delete one copy of the word Jane.
I-language will map onto different E-languages in different ways. Chomsky’s notion of unbounded Merge, recursively applied, is therefore essentially an idealization, inferred from the study of external languages, but is not in itself directly observable. pp. 23-24
It’s notable that whatever the other merits of the Merge, it does appear to be a good description of how language is extended via metaphor. I recently ran across a good example of this: the word inosculation, meaning to homogenize, make continuous or interjoin. It’s root is the verb “to kiss”, which itself is derived from the word for “mouth.” This word, like so many others, was created through recursion and metaphor.
From in- + osculate, from Latin ōsculātus (“kiss”), from ōs + -culus (“little mouth”).
The sheer diversity of human languages that have been found and studied has put Chomsky’s Universal Grammar theory on the cooler. There does not seem to be any sort of universal grammar that we can find, nor a universal method of thought which underlies it. A few languages have been discovered that do not appear to use recursion, most famously the Pirahã language of the Amazon, but also the Iatmul language of New Guinea and some Australian languages spoken in West Arnhem land. For example, the phrase “They stood watching us fight” would be rendered as “They stood/they were watching us/we were fighting.” in Bininj Gun-Wok (p. 27)
Recursion and Human Thought: A Talk with Daniel Everett (Edge Magazine)
It continues to be debated whether animals have a capacity for recursive expression. A study on 2006 argued that starling calls exhibited a recursive quality, but this has been questioned. As I mentioned earlier, it is often difficult to tell if something which may appear recursive is actually generated recursively.
Starlings vs. Chomsky (Discover)
Corballis argues here (as he has in other books, which I will also refer to), that the human mental capacity for language evolved first via gesticulation (hand gestures), rather than verbal sounds (speech). Only much later, he argues, did communication switch from primarily hand gestures to speech. “I have argued…that the origins of language lie in manual gestures, and the most language-like behavior in nonhuman species is gestural.” (p. 161) Some reasons he gives for believing this are:
1.) We have had extensive control over our arms, hands and fingers (as demonstrated by tool use and manufacture, for example) for a millions of years, but the fine motor control over our lungs and vocal tract required to produce articulate speech is of far more recent vintage. It is also unique to our species—other apes don’t have the control over the lungs or mouth required for speech. In fact, the unique control that humans possess over their breathing leads Corballis to speculate that distant human ancestors must have spent considerable time diving in water, which requires extensive breath control. Human babies, for example, instinctively know to hold their breath in water in a way that other apes—including our closest relatives—cannot. This leads him to endorse an updated version of the Aquatic Ape theory called the Littoral hypothesis, or the Beachcomber theory.
In an extensive discussion of the aquatic ape hypothesis and the various controversies surrounding it, Mark Verhaegen suggests that our apelike ancestors led when he calls an aquarborial life, on the borders between forest and swamp lands. There they fed on shellfish and other waterbourne foods, as well as on plants and animals in the neighboring forested area…In this view, the environment that first shaped our evolution as humans was not so much the savanna as the beach. During the Ice ages the sea levels dropped, opening up territory rich in shellfish but largely devoid of trees. Our early Pleistocene forebears dispersed along the coasts, and fossils have been discovered not only in Africa but as far away as Indonesia, Georgia, and even England. Stone tools were first developed not so much for cutting carcasses of game killed on land as for opening and manipulating shells. Bipedalism too was an adaptation not so much for walking and running as for swimming and shallow diving.
Verhaegen lists a number of features that seem to have emerged only in Pleistocene fossils, some of which are present in other diving species but not in pre-Pleistocene hominins. These include loss of fur; an external nose; a large head; and head, body, and legs all in a straight line. The upright stance may have helped individuals stand tall and spot shellfish in the shallow water. Later, in the Pleistocene, different Homo populations ventured inland along rivers and perhaps then evolved characteristics more suited to hunting land-based animals. The ability to run, for instance, seems to have evolved later in the Pleistocene. But Verhaegen suggest that, in fact, we are poorly adapted to a dry, savannalike environment and retain many littoral adaptations (that is, adaptations to coastal regions): “We have a water- and sodium-wasting cooling system of abundant sweat glands, totally unfit for a dry environment. Our maximal urine concentration is much too low for a savanna-dwelling mammal. We need much more water than other primates and have to drink more often than savanna inhabitants, yet we cannot drink large quantities at a time.
Part of the reason for our swollen brains may derive from a diet of shellfish and other fish accessible the shallow-water foraging [sic]. Seafood supplies docosahexaenoic acid (DHA), an omega 3 fatty acid, and some have suggested that it was this that drive the increase in brain size, reinforcing the emergence of language and social intelligence.
Michael A. Crawford and colleagues have long proposed that we still need to supplement our diets with DHA and other seafoods to maintain fitness. Echoing Crawford, Marcos Duarte issues a grim warning: “The sharp rise in brain disorders, which, in many developed countries, involves social costs exceeding those of heart disease and cancer combined, has been deemed the most worrying change in disease pattern in modern societies, calling for urgent consideration of seafood requirements to supply the omega 3 and DHA required for brain health.
The Truth About Language: What It Is and Where It Came From; pp. 95-97
2.) Chimpanzees appear to have little control over the types of sounds that they make. Vocalization in primates appears to be largely instinctual, and not under conscious control.
3.) Although apes such as chimpanzees, bonobos and gorillas cannot learn spoken language, they can be taught to communicate with humans using sign language. Apes have learned vocabularies of several thousand signed words, most notably Koko the gorilla, and the bonobo Kanzi.
Manual activity in primates is intentional and subject to learning, whereas vocalizations appear to be largely involuntary and fixed. In teaching great apes to speak, much greater success has been achieved through gesture and the use of keyboards than through vocalization, and the bodily gestures of apes in the wild are less contained by context than are their vocalizations. These observations strongly suggest that language evolved from manual gestures. p. 57
4.) Mirror neurons are neurons in our brain that fire not in response to an action, but in response to watching someone else perform that action. They were first discovered in monkeys (sometimes called “monkey-see, monkey-do” neurons), but are present in all apes. These are part of a larger network of regions called the mirror system. It has been proposed that language grew out of this mirror system. The underlying idea is that, “[W]e perceive speech not in terms of the acoustic patterns it creates, but in terms of how we ourselves would articulate it.” (p. 61) This called the motor theory of speech perception. If this theory is true, it would point to an origin of language in gestural imitation rather than calls, which do not recruit mirror neurons in other primates.
The mirror system, in contrast to the primate vocalization system, has to do with intentional action, and is clearly modifiable through experience. For example, mirror neurons in the monkey brain respond to the sounds of certain actions, such as the tearing of paper or the cracking of nuts, and these responses can only have been learned. The neurons were not activated, though, by money calls, suggesting that vocalization itself is not part of the mirror system in monkeys…
…in the monkey, mirror neurons responded to transitive acts, as in reaching for an actual object, but do not respond to intransitive acts, where a movement is mimed and involves no object. In humans, by contrast, the mirror system responds to both transitive and intransitive acts, and the incorporation of intransitive acts would have paved the way to the understanding of acts that are symbolic rather than object-related…functional magnetic resonance imaging (fMRI) in humans shows that the mirror-neuron region of the premotor cortex is activated not only when they watch movements of the foot, hand, and mouth, but also when they read phrases pertaining to these movements. Somewhere along the line, the mirror system became interested in language. p. 62
5.) The anatomical structures in the mouth and throat required to produce something like human vocal patterns (phonemes) also came fairly late in human evolution. There is no evidence that even archaic humans could do it properly:
One requirement for articulate speech was the lowering of the larynx, creating a right-angled vocal tract that allows us to produce the wide range of vowels that characterize speech. Philip Lieberman has argued that this modification was incomplete even in the Neanderthals…Daniel Lieberman…had shown that the structure of the cranium underwent changes after we split with the Neanderthals. One such change is the shortening of the sphenoid, the central bone of the cranial base form which the face grows forward, resulting in a flattened face. The flattening may have been part of the change that created the right-angled vocal tract, with horizontal and vertical components of equal length. This is the modification that allowed us the full range of vowel sounds, from ah to oo.
Other anatomical evidence suggests that the anatomical requirements for fully articulate speech were probably not complete until late in the evolution of Homo. For example, the hypoglossal nerve, which innervates the tongue, is also is much larger in humans, perhaps reflecting the importance of tongued gestures in speech. The evidence suggests that the size of the hypoglossal canal in early australopithecenes, and perhaps in Homo habilis, was within the range of that in modern great apes, while that of the Neanderthal and early H. sapiens skulls was contained will within the modern human range, although this has been disputed.
A further clue comes from the finding that the thoracic region of the spinal cord is relatively larger in humans than in nonhuman primates, probably because breathing during speech involves extra muscles of the thorax and abdomen. Fossil evidence indicates that this enlargement was not present in early hominins or even in Homo eragaster, dating from 1.6 million years ago, but was present in several Neanderthal fossils.
Emboldened by such evidence…Phillip Lieberman has recently made the radical claim that “fully human speech anatomy first appears in the fossil record in the Upper Paleolithic (about 50,000 years ago) and is absent in both Neanderthals and earlier humans.” This provocative statement suggests that articulate speech emerged even later than the arrival of Homo sapiens some 150,000 to 200,000 years ago. While this may be an extreme conclusion, the bulk of evidence does suggest that autonomous speech emerged very late in the human repertoire…pp. 72-74
Primer: Acoustics and Physiology of Human Speech (The Scientist)
Interestingly, despite the anatomical evidence for a late development of language being fairly recent, Jaynes argued for a Pleistocene origin for speech in Homo sapiens (but not other archaic humans) back in 1976. He also implied that communication was unspoken, possibly through hand gestures much the way Corballis argues:
It is commonly thought that language is such an inherent part of the human constitution that it must go back somehow through the tribal ancestry of man to the very origin of the genus Homo, that is, for almost two million years. Most contemporary linguists of my acquaintance would like to persuade me that this is true. But with this view, I wish to totally and emphatically disagree. If early man, through these two million years, had even a primordial speech, why is there so little evidence of even simple culture or technology? For there is precious little archaeologically up to 40,000 B.C., other than the crudest of stone tools.
Sometimes the reaction to a denial that early man had speech is, how then did man function or communicate? The answer is very simple: just like all other primates with an abundance of visual and vocal signals which were very far removed from the syntactical language that we practice today. And when I even carry this speechlessness down through the Pleistocene Age, when man developed various kinds of primitive pebble choppers and hand axes, again my linguist friends lament my arrogant ignorance and swear oaths that in order to transmit even such rudimentary skills from one generation to another, there had to be language.
But consider that it is almost impossible to describe chipping flints into choppers in language. The art was transmitted solely by imitation, exactly the same way in which chimpanzees transmit the trick of inserting straws into ant hills to get ants. It is the same problem as the transmission of bicycle riding: does language assist at all?
Because language must make dramatic changes in man’s attention to things and persons, because it allows a transfer of information of enormous scope, it must have developed over a period that shows archaeologically that such changes occurred. Such a one is the late Pleistocene, roughly from 70,000 B.C. to 8000 B.C. This period was characterized climatically by wide variations in temperature, corresponding to the advance and retreat of glacial conditions, and biologically by huge migrations of animals and man caused by these changes in weather. The hominid population exploded out of the African heartland into the Eurasian subarctic and then into the Americas and Australia. The population around the Mediterranean reached a new high and took the lead in cultural innovation, transferring man’s cultural and biological focus from the tropics to the middle latitudes. His fires, caves and furs created for a man a kind of transportable microclimate that allowed these migrations to take place.
We are used to referring to these people as late Neanderthalers [sic]. At one time they were thought to be a separate species of man supplanted by Cor-Magnon man around 35,000 B.C. But the more recent view is that they were part of the general human line, which had great variation, a variation that allowed for an increasing pace of evolution, as man, taking his artificial climate with him, spread into these new ecological niches. More work needs to be done to establish the true patterns of settlement, but the most recent emphasis seems to be on its variation, some group continually moving, others making seasonal migrations, and others staying at a site all the year round.
I am emphasizing the climate changes during this last glacial age because I believe these changes were the basis of the selective pressures behind the development of language through several stages. OoCitBotBM; pp. 129-131
Thus, Jaynes falls into the camp that argues that language was the decisive factor in the transition to behavioral modernity as seen in the archaeological record (as do many others). This would also explain the relative stasis of cultures like that of Homo erectus, whose tools remained basically unchanged for thousands of years and had no signs of art, music, or any other kind of abstract thinking.
6.) People using sign language utilize the exact same areas of the brain (as shown by fMRI scans, for example) as people engaged in verbal speech.
Even in modern humans, mimed action activates the brain circuits normally thought of as dedicated to language…activities elicited activity in the left side of the brain in frontal and posterior areas–including Broca’s and Wernicke’s areas–that have been identified since the nineteenth century was the core of the language system…these areas have to do, not just with language, but with the more general linking of symbols to meaning, whether the symbols are words, gestures, images, sounds, or objects….We also know that the use of signed language in the profoundly deaf activates the same brain areas that are activated by speech…p. 64
7.) Hand gestures do not require linearalization. Corballis gives the example of an elephant and a woodshed. While some words do sound like what they describe (onomatopoeic words), most do not. In fact, they cannot. Thus, it would be difficult for sounds alone to distinguish between things such as elephants and woodsheds. Gestures, however, are much less limited in their descriptiveness.
Speech…requires that the information be linearalized, piped into a sequence of sounds that are necessarily limited in terms of how they can capture the spatial and physical natures of what they represent…Signed languages are clearly less constrained. The hands and arms can mimic the shape of real-world objects and actions, and to some extent lexical information can be delivered in parallel instead of being forced into a rigid temporal sequence. With the hands, it is almost certainly possible to distinguish an elephant from a woodshed, in purely visual terms. pp. 65-66
But see this: Linguistic study proves more than 6,000 languages use similar sounds for common words (ABC)
Over time, sounds may have supplemented hand gestures because they are not dependent on direct lines of sight. They can also transmit descriptive warning calls more effectively (“Look out, a bear is coming!”). Corballis speculates that facial gestures became increasingly incorporated with manual gestures over time, and that these facial gestures eventually also became combined with rudimentary sounds. This was the platform for the evolution of speech. Finally, freeing up the hands completely from the need for communication would have allowed for carrying objects and tool manufacture that was simultaneous with communication.
The switch, then, would have freed the hands for other activities, such as carrying and manufacture. It also allows people to speak and use tools at the same time. It might be regarded, in fact, as an early example of miniaturization, whereby gestures are squeezed from the upper body to the mouth. It also allows the development of pedagogy, enabling us to explain skilled actions while at the same time demonstrating them, as in a modern television cooking show. The freeing of the hands and the parallel use of speech may have led to significant advances in technology, and help explain why humans eventually predominated over the other large-brained hominins, including the Neanderthals, who died out some 30,000 years ago. p. 78
Incidentally, miniaturization, or at least the concept of it, also played a critical role in tool development for Homo sapiens: From Stone Age Chips to Microchips: How Tiny Tools Made Us Human (Emory University)
Eventually, speech supplanted gesture as the dominant method of communication, although hand gestures have never completely gone away, as exemplified by mimes, deaf people, and Italians. Gestures, such as pointing, mimicking, and picking things up, are all still used during the acquisition of language, as any teacher of young children will attest.
Why apes can’t talk: our study suggests they’ve got the voice but not the brains (The Conversation)