Saturday, March 3, 2012

Adam's Tongue: How Humans Made Language, How Language Made Humans

Book Review: Adam’s Tongue: How Humans Made Language, How Language Made Humans by Derek Bickerton   (Hill and Wang 2009)

 This is a mind-blowing account of how we may well have discovered and developed both language and conceptual thought. By no means is this sometimes complex scenario certain but the logic is compelling and the story coherent even though some assumptions have to be made. Cutting edge ideas in evolution are all through this book. The author dukes it out with all the current ideas about language origins and points out many shortcomings. The book is fascinating and holds one’s interest well. The only problem I have with it is that he did not summarize enough after his initial arguments to package it up finer and into a more coherent whole. Bickerton is a linguistics professor but he is quite well-studied in evolutionary biology as well.

Bickerton notes that the question of language origins is very important in science for without language there would be no science. Language is perhaps what makes us human – or beyond mere animals. For all the great sensory and biological abilities of various animals it seems that language is of a magnitude greater. He notes that the evolution of language is a difficult problem to unravel. Did brain size and intelligence make language or vice versa. Or was some of the process co-evolutionary. These are some of the questions pondered. He compares the development of language in humans to the development of flight in insects. He thinks that language is the key to being human. Bickerton sees things more as a loop between genes and environment rather than as all genes a la Richard Dawkins. He also warns against regarding language as a target for natural selection. Many things have been proposed that caused language to be selected: “hunting, toolmaking, child care, social competitiveness, sexual display.” He debunks all these as triggers for language to have been selected but does note that they all have a role in the further development of language after a rudimentary functional language was in place.

He begins with a discussion of Animal Communication Systems (ACS). He points out that these are not at all similar to language and certainly not a close precursor to language – or rather, that there is no hierarchy from ACS to language. He goes through Marc Houser’s criteria for ACS – three broad categories that can overlap: 1) signals that relate to survival, 2) signals that relate to mating and reproduction, 3) social signals. These are how animals communicate in order to increase survival and reproductive success. So survival, mating, and social signals make up the full amount of ACS. The author points out that ACS are concerned with the present, that they are grounded in the here and now, and before language there is no real notion of past and future. Later he notes that animals have an ‘episodic memory’ which is a vague connection to the past, but do not really have memory or a real conception of past and future. Words and language, on the other hand, express qualities that go beyond the present. ACS are concerned strictly with survival fitness. Humans alone, he says, developed a need for language.

Bickerton analyzes and debunks language origin theories having to do with tools, hunting, sex, and grooming and gossip. He notes four tests that any theory of language must pass: 1) Uniqueness – why humans uniquely acquired language and no other species did; 2) Ecology – environment of humans that developed language needs to be taken into account; Credibility – the theory must be credible – he doses not really explain this condition well; 4) Selfishness – there should have been some selfish benefit.

Bickerton systematically rejects the idea that humans developed language as a function of increasing brain size. His conclusion is more that language allowed us to develop bigger brains rather than bigger brains being an impetus fro the development of language.

He goes through the development of language in terms of linguistics theory – from phonology – meaningless sounds, to morphology – sounds with meaning, to syntax – meaningful utterances that we understand as language.

One area of Bickerton’s expertise is with pidgin language development and here he sees a parallel to the development of early language where whatever worked to affect the transfer of ideas was used – words, sounds, gestures, body language, emphasis, etc. He does note his detractors who don’t think pidgin is a good model for language development. He sees pidgin as something intermediate between ACS and language as we know it, a protolanguage. The factor that language shares with protolanguage beyond ACS, he says, is ‘combinability.’

“Languages combine lawfully and protolanguages combine lawlessly. In other words, languages have all kind of constraints on what you may put together with what; protolanguages don’t.”

So language has syntax but protolanguage need not have it. ACS, he says, have no combinability and cannot have it. No precursor to syntax has ever been found in an ACS.

Predication, he says, is the precursor to syntax, and this requires combinablity (of sounds) in some meaningful way. Much of the search for the link between ACS and language has been involved with alarm calls among primates. They have different ones for different threats such as eagle, snake, or leopard, though these only refer indexically to the animals themselves or to threats from above, near, or below. He notes that some have tried to suggest combinability – of such things as calls for food and danger – but when analyzed they are two separate calls and not blended or combined into one.

ACS signs are indexical rather than symbolic – indexical signs point directly at what they refer to. Symbolic signs are not confined to the here and now and so are in the domain of language. He notes that both ACS and language are both informative and manipulative. ACS is primarily manipulative and only secondarily informative, while language is primarily informative and only secondarily manipulative. Information is only a byproduct of ACS. Manipulative signals are confined to the here and now while informative signals are not. He contends that symbolism rather than syntax is the uniquely human ability that allowed language to develop. In terms of development beyond ACS it was ‘displacement’ (in space and time beyond the here and now) that had to develop. Of the three types of ACS signals, it is only survival (and not mating or social signals) he explains that could have made the leap to displacement. ACS survival signals can be divided into alarm calls and food calls. Distance of newly discovered food and time to reveal news of such food is a candidate situation for displacement to have developed. There is a third class of signal different from the indexical and symbolic. This is the iconic, which is something that resembles what it refers to such as mimicking the noise a certain animal makes. This is the route (from icon to symbol) he thinks the development of symbolic language took. He gives the selective pressure as “the need to transmit information about food sources outside the sensory range of message recipients” and the means of doing this through iconic signs.

He talks a lot of the “primate-centric bias” where genetics is seen as the most influential factor on language development and perpetuated by the determinism of Richard Dawkins and many others and the focus on other primates in the search for the development of language. So ape ACS has been a main focus in this search. He goes through some theories where language is presumed to be derived from primate ACS – the primate gestures idea of Pollick and de Waal and the theory of the singing apes (as a pair-bonding mechanism) of Mithen. He re-iterates that ACS and language are different things – that ACS did not necessarily directly evolve into language.

He goes through and debunks the ‘talking apes’ experiments to teach language to apes and shows that it is not symbolic language that they are learning but an a learned extension of their ACS. He sees these experiments as teaching the apes a rudimentary form of protolanguage – with some combinability. He suggests that their neurology was altered in the sense that, “Neurons that fire together, wire together.”

Homology is discussed – ie. genetic possibilities related to earlier animal forms that lie dormant in genes. Intra-species communication among other species, particularly social insects such as ants and bees indicates a latent genetic capability for deeper than ACS communication.

Next he goes through the very interesting theory of niche construction. In explaining this he gives the example of beavers. They designed their environments by making them but their environments have designed them as well – their tails, their teeth, their mouth configuration, their eyelids, their webbed feet, and their thick fur. As the author states it, it is a situation where:  “Chance + Necessity + Time = Perfect Fitness.”

“… it’s the interaction between genes and behavior that starts the evolutionary motor, and feedback between genes and behavior that keeps it going. That’s the insight that gave birth to niche construction theory.”

“… animals themselves modify the environments they live in, and that these modified environments, in turn, select for further genetic variations in the animal. So a feedback process begins, a two-way street in which the animal is developing the niche and the niche is developing the animal, until you get the lock-and-key fit between the animal and niche that makes people say, “But there must  have been a designer!”

In defining a niche Bickerton notes three components of a niche: 1) habitat – macro and/or micro, 2) nourishment, and 3) means of obtaining food or nourishment. Though one may not think of niches as being actively constructed, many are in nature. Farming is niche construction, including ants that farm fungi or aphids. Earthworms construct their niche. Termites construct climate controlled dwellings. The photosynthesis of plants constructs a niche that allows other species, those that breathe oxygen, to thrive. The bottom line is that it is not just the species that makes the niche but the niche that makes the species. Humans, he says, have the greatest capacity to adapt the environment to their own needs. So what he says is that the development of language among humans is a form of niche construction. Humans, it seems, constructed new niches at unprecedented scale and speed. He thinks that the search for a gene for language is ultimately futile as niche construction explains language development rather than genetics. He says that alarm calls did not morph into words but probably helped ready us for words.

His explanation begins with the niche carved out by australopithecines about 2.5 mya. Aside from possible endurance hunting and living in constant danger from predators due to their small size he thinks that these proto-humans ate by foraging and by scavenging. The scavenging hierarchy would have been led by larger fiercer predators with vultures at the lowest followed by the lowliest – the humanoids. He and others think they were last but they figured out how to crack bones and devour the nutrient-dense marrow. Bones of large herbivores would have been plentiful, long-lasting, and without competition. This nutrient-dense marrow may have resulted in increased brain growth. Even so there is only a small amount of marrow in bones. Dead megafauna would have been relatively abundant. These are large animals that could not be taken down by predators – things like mammoths and hippos. They have very thick skins that predators cannot rend until they decompose for a few days. The theory is that the humans – normally at the low end of the scavenging totem pole, found that they could go in before the predators and cut open the thick skin with sharp volcanic rocks or flint. There is evidence for this in the fossil record. Up until 2 mya the cut marks on fossil bones came after predator marks – suggesting humans utilizing the bones for marrow. After this time the cut marks seem to occur before the predator marks indicating that humans got there first. This indicates a new form of scavenging and the author places it in terms of ‘optimal foraging theory’ which states that, “… any species will choose, out of available foods, just those that yield the highest calorific intake relative to the energy that’s expended in obtaining them.” This change in foraging strategy would have required these early humans to range over larger distances than before – which is indicated in the fossil record. According to the theory the humans would have to find the recently dead megafauna, quickly gather sufficient numbers of humans with sharp stones to hurl at carnivores who would be hovering near and try to move in especially as they smelled the meat better as the skin was pierced.

Next he digresses to discuss evolutionary and development biology – known as “evo-devo” which suggests that homology is more widespread than thought. Homology means going back, sometimes way back, to common ancestors to see how features developed in some but not in others – though the genes they developed from are still there, latent. If a similar niche comes about in a totally different species much later on,  that species may draw on the same genetic material in a similar way. Here he is referring to the selective pressure of the need to transmit information about food sources beyond the sensory range of recipients of that information. Both ants and bees are able to do this. Bees do it through dance and reference to the sun’s position. Ants do it through shaking displays and chemicals. This transmission behavior can be seen as a form of recruiting. Some ants, like early humans, practice a fission-fusion feeding strategy, that is, they spread out and regroup and information is transmitted (chemically) about big sources of food. Ravens scavenge with a single carcass claimed by bonding pairs though a single raven may recruit others to drive off a pair. These are all homologies of recruiting behavior regarding food sources.

He suggests that a group ancestral to homo erectus broke of from homo habilis by going from catchment scavenging (bone marrow) to territorial scavenging (dead megafauna). This would require evolutionary changes over time – bigger size, ability to withstand thirst, better throwing ability, and bigger size. He goes through a scenario where these pre-lingual humans scattered in foraging bands – where one locates a dead megafauna and gathers others to hurry and butcher it while fending off predators with their numbers and hurling sharp stones. When a dead animal was located there arose the problem of recruitment, how to gather the other bands together quickly in order to get at the food. So iconic language – like the sounds of the dead animal were likely first uttered with a desire to utter notions like “come now!”  “this way!” One possible source of evidence is the large number of so-called hand axes found together – he suggests these were not hand axes but the stones hurled at predators. He suggests it was the women who did the butchering – being protected furthest from the predators, the stone-throwing men being more expendable. So this recruitment is a form of cooperation that yields benefit that can only be derived by gathering sufficient numbers. This situation, he notes, would require non-kin cooperation, which would have been a new thing.

He donates a section to the alternative ideas of language development put forward by Noam Chomsky. He disagrees with Chomsky on the ultimate origins of language but agrees with him on many other linguistics issues and is not at all part of what he says is an existing anti-Chomsky faction. Chomsky, an expert in linguistics, had not mentioned language origins until he co-authored a paper in 2002. Here a compromise was made where the ‘faculty of language’ was divided into a broad faculty (BFL) and a narrow faculty (NFL). Hauser, one of the co-authors, believes language to have developed due to natural selection. The notion of recursion – “the capacity to embed one linguistic structure within another of the same kind – one phrase, clause, or sentence inside another” was part of FLN – that which is unique to humans and specifically dedicated to language. FLB could have developed from other biological needs. I don’t quite understand all these features but the bottom line is that Chomsky etal were saying that animals first had concepts that would not merge with other concepts. When concept merging appeared the brain was re-wired. Merging then was further developed and complex thought, planning, and language developed. The author disagrees with this sequence. He thinks that though the early humans may have had some categorizing abilities, proto-concepts of a sort, that actual language appeared before conceptualization (which is often defined as language-based thought). Of course, after a few words were learned by necessity, concepts could be further developed and lead to more words in a feedback system. This likely did not happen quickly – at first, although once it began to really happen it may taken off. Categories, he suggests, can trigger episodic memories in animals neurologically as a threat or potential food source is located but if the threat or food is not potentially present in the mind, in the here and now, then the neurons won’t fire. Concepts require defining something when it is not present. If there is no threat or no potential satisfaction then there is no biological need for the idea. The neurons are related to the threat or the satisfaction rather than to the thing that provides it. When they become related to the thing then the process would be conceptual. He gives an analogy of RAM (random access memory) and CAM (content addressable memory) with computers. CAM is more complex and more energy expensive – more like real concepts versus survival categorization. So he is saying that words allowed concepts as we know them to form neurologically. He compares online thinking and offline thinking. Online thinking refers again to the here and now and offline thinking refers to ideation of things not present. After words were developed then thought and language could co-evolve. After rudimentary language developed then all the things thought to have started language like – “instructing the young, competing socially, displaying sexually, making artifacts, gossiping, performing rituals …” would be free to be enhanced and further developed. The vast time required for the extensive re-wiring of the brain would have taken hundreds of thousands of years and during that time the human brain did gradually double in size though no major changes in human tools came about (from 2mya) for about a million years.

The recruitment signals that went beyond ACS had functional reference, had displacement, were learned, and contained protonouns (names for species), and possibly protoverbs (“come” “hurry”). In order for language to develop these signs would have had to uncouple from situations, from the here and now, and from survival fitness. Words for past and future would have had to develop and cooperation beyond that required for fitness would have had to develop before these uncouplings could take place. That is why he suggests that language did not develop right away from these recruitment signals even though they were the first break from ACS toward language. He thinks displacement was the single most influential factor in developing symbolical thinking. He suggests that a recruitment signal for say “mammoth” may have been imitated by the young and gradually the signal sound gets divorced from the immediacy of the situations where it arises and eventually a representation forms in the brain. Perhaps there were ritual re-enactments of the scavenging missions at some point and this would reify the symbols in the brains. Once symbolic thinking developed the territorial scavenging foraging strategy could be improved by noting and communicating signs suggesting possible dying megafauna. Next he thinks came the development of syntax – maybe a hundred thousand years ago as he suggests – the development of barbed weapons suggested that syntax was appearing conceptually. The barbed weapon requires a sequence of events to be learned with regard to the weapon interfacing with the animal. In light of this he thinks protolanguage was like a pidgin language with emerging syntax. Then it became possible to link concepts into coherent trains of thought. He thinks that the earliest protolanguage contained very few words with no sound overlap and that vocabulary building came much later and that the development of vocabulary selected for greater phonological complexity. Gradually, as is now well known, we developed language faculties with which we are born. He says predication preceded true syntax perhaps in the manner of sequencing words as in pidgin. Words were probably originally linked as “beads on a string” and later developed hierarchical orders which became universal as true language developed. He calls language development an auto-catalytic process – one that drives itself – due to a need for greater effectiveness and to convey more in a short time period. Hierarchical structured speech is faster than pidgin. This structure is what Chomsky calls Merge. Brevity and clarity are other factors that get enhanced with structured syntax. Needs to distinguish things of different types and to qualify things are the types of things that led to greater complexity.

In the last section he analyzes and criticizes the idea of recursion – phrases within phrases. Chomsky uses it to argue that language is cultural rather than biological but the author thinks that the origin of language is ultimately biological. This seems a bit strange or rather obvious to me as it seems that culture itself is ultimately biological so the biological origin seems much more likely to me. 

Anyway – this is an awesome book that really opens up some thought about what it really means to be human.

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