Average male IQ greater than average female IQ

From BBC News:

Academics in the UK claim their research shows that men are more intelligent than women.

A study to be published later this year in the British Journal of Psychology says that men are on average five points ahead on IQ tests.

Paul Irwing and Professor Richard Lynn claim the difference grows when the highest IQ levels are considered.

Their research was based on IQ tests given to 80,000 people and a further study of 20,000 students.

‘Widening gap’

Dr Irwing, a senior lecturer in organisational psychology at Manchester University, told the Today programme on BBC Radio Four the study showed that, up to the age of 14, there was no difference between the IQs of boys and girls.

“But beyond that age and into adulthood there is a difference of five points, which is small but it can have important implications,” he said.

Seems that the paper will be published later, so details will have to come from the press.

Going back to the Meccan well….

I have been reading some chapters of A History of Islamic Societies recently, and I noticed something interesting. But first some context. I have read a lot about the dynamics of Indonesian, in particular Javanese, society for many years. The reason is that on this island of 100 million you have a nominally Muslim society which expresses the full range of Islam from “orthodox” Arabicized practice and belief (the urban reformist santri) to nominal Muslims whose practice is so close to Indonesian Hinduism1 that since the 1960s many of them have been switching to that religion. Until recently my conception of the emergence of a urban literate santri was that it was an inevitable result of a closer reading of the source texts and traditions of Islam, the Koran and the Hadiths. In other words, santri Muslims were simply more Muslim than the typical Javanese Muslim (an increase in the magnitude of the same vector).

But, as some know, I have also expressed skepticism at too close of a reliance on texts as determinative on the pathway of social and cultural development. In the chapters in the above book on 19th century Indian Islam I noted something interesting: reformist neo-orthodox movements are repeatedly attributed to hajjiis, those who made the pilgrimage to Mecca, in particular those who had resided in the city for long periods of time. The prestige that they attained upon their return resulted in their initiation of “reforms” to bring local practices (often loosely classified as “Sufi”) into line with Meccan norms. The same “reforms” were initiated by Hui who had returned from Mecca. And sure enough, the chapter on Southeast Asian Islam notes that the modernist reformist Muslims who rose to challenge the traditional expressions of Javanese Islam were also inspired by movements founded by hajjiis!

In The Meme Machine Susan Blackmore characterizes some individuals as “meme fountains.” It seems clear to me that the hajjiis were operating as meme fountains when they returned from Arabia and the sacred physical heart of Islam, Mecca. The practices of Meccan Islam are in some ways unchallengeably normative, and so the hajjiis had the moral authority to “reform” local practices which deviated from the Meccan norm. Richard Dawkins explained the neo-memetic ideas of Blackmore in part as fidelity to an original source which was abstracted and converted into clear heuristics so as to make errors unbiased (and so non-progressive). The original template served to anchor propogated ideas and practices which did not replicate duplication errors. The standard model promoted by many is that the Koran and Hadiths serve as that template. I dissent from this view because my own reading of cognitive science suggests that religious texts are easily warped and distorted by “learned consensus” or personal self-interest. They do not exhibit the transparent inferential characteristics of mathematical axioms, ergo, the often strained verbal gymnastics of the religious “sciences.” Rather, I am suggesting that the template is more likely to be the norms espoused by the Muslims of Mecca.

This has an implications: the hajj is far more common today than it was in the past. There are millions of hajjiis every year (the Saudi government even has to limit it). In synergy with communication technologies that implies that the number of meme fountains might be far greater than in the past (though the more mundane nature of the hajj because of modern transporation might mitigate the influence of hajjiis). Efforts to tailor or accommodate Islam to local norms must be balanced against the conformist tendencies of the meme fountain generator that is Mecca. Additionally, the character of Meccan Islam is partly dictated by the Saudi state, which frowns upon non-Wahhabi or Salafist practices (though Meccan Muslims resist the Saudi orthodoxy).

In the past the Dar-al-Islam was an idea that appealed to elites, for only elites were literate and practiced an Islam which was characterized by punctilious adherence to the norms of sharia (this is more true of the non-Arab world). Today many regions of the Muslim world are modernizing (eg; Malaysia) and literacy and access to source texts is spreading. With it is an attempt to generate a common set of Islamic norms. But I think it is important not to neglect the physical presence of hajjiis throughout the Muslim world and their direct experience and understanding of how Islam is practiced in the city of Muhammed. It is often said that Malcom X’s encounter with blue-eyed Muslims in Mecca was relevatory for him, and changed his understanding of what Islam is. I suspect that this is but the tip of the iceberg of what is going on, and any attempt to understand how Islam is developing needs to include an ethnography of the hajjiis.

1 – Indonesian Hinduism, typified by the religious practices of Bali, is not the same as Indian Hinduism, ergo, the qualifier. The Balinese are not the only Indonesian Hindus, there remained through the Muslim period communities of identified Hindus in Java, especially in the eastern regions and in the highlands. Since 1965 there has been a trend for heterodox religious movements and individuals to give their affiliation as Hindu to avoid religious persecution (the national ideology demands that citizens be a member of one of the major religious groups, Islam, Christianity, Buddhism or Hinduism). Some of these groups are close to being Hindu in name only.

"Asian" and "Western" thinking….

A reader pointed me to this new research out in PNAS that suggests that “…Westerners attend more to focal objects, whereas East Asians attend more to contextual information.” Scientific American has a popular press piece up on this as well. The reader wondered why the researchers focused on cultural rather than biological factors. To understand, I think you need to have read Nisbett’s book, The Geography of Thought (see my review), where he introduces many of the ideas that loom in the background of this paper. In the book Nisbett notes that Anglo-Saxons1 and East Asians are his two model cultures, but that Continental Europeans tend to “think” in a hybrid fashion, while most other peoples view the world as East Asians do. Phylogenetically Europeans are not located between East Asians and Anglo-Saxons, they are on a continental scale almost indistinguishable from Anglo-Saxons. Similarly, various non-European groups are not particularly closely related to East Asians vis-a-vi Anglo-Saxons. Also, Nisbett even presents evidence in his book that Anglo-Saxons and East Asians can be “trained” to respond to questions like the other group by simply giving them explicit instructions on what to look for (the training can last as little as an hour). But there is a more important piece of evidence. Here is a fragment from a paper titled Cultural Preferences for Formal versus Intuitive Learning:

…European Americans, more than Chinese or Koreans, set aside intuition in favor of formal reasoning. Conversely, Chinese and Koreans relied on intuitive strategies more than European Americans. Asian Americans’ reasoning was either identical to that of European Americans, or intermediate…. [* see note below]

Certainly formal and intuitive reasoning are genetically controlled to some extent, and I am willing to bet that many cognitive biases on the individual level can contribute to whether one prefers formal or intuitive reasoning. Perhaps the “central tendency” in terms of formalism vs. intuition of different populations might be different assuming the same environmental background. But the results from Asian Americans suggest that a great deal of the bias is culturally mediated. One could posit Baldwin Effects strengthening the cultural bias but it seems plausible that this process has not gone very far along. For example, I would argue that the individualism of Anglo-Saxon cultures as a mass society value is a relatively recent affair (though the aristocratic perception of Rights and Prerogatives are eternal!).

Related: Chris has much more on this topic. John expresses skepticism.

1 – Short hand for the English speaking world.

* This is why I give props to the Greeks for popularizing the formal proof in mathematics. I don’t think it is a “normal” way to think, and the Chinese, certainly not a dull people, tended not to stab at problems in this fashion. Neither did Indian mathematicians, and even the great Ramanujan was not much of a formalist from what I gather.

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Culturally Authentic Recipe Club

Contemporary Americans don’t eat the same dishes as Medieval Europeans because because many foods in a modern American diet were not available to Medieval Europeans. They either hadn’t been discovered by Europeans yet, such as New World foods like maize, potatoes, and chocolate, or were unavailable for other reasons, such as pepper and other spices, which were expensive luxuries then.

When devising recipes, medieval cooks like Taillevent had to take into account the amount of leftovers and how perishable they would be given the lack of refrigeration as well as how reliable his supply of quality ingredients was. Almond milk, for example, used to be commonplace for a number of reasons. In addition to its inherent perishability, cow’s milk was often sold by unscrupulous dealers who adulterated their product or sold spoiled milk as fresh. Almonds were much less perishable and a reliable supply could be kept on hand.

Old recipes are often the best that a cook could devise given the constraints at the time. Mooncakes, for example, have decreased in popularity as the Chinese community has been exposed to lighter goodies like Portugese egg tarts and Australian (no, I don’t mean Austrian) apple strudel and adopted them as their own.

Now if you’ll excuse me, I’m hungry.

Bushy phylogenies….

A new report is coming out of Dmanisi, Georgia, about a 1.8 million “Homo erectus” skull. This is a site that has generated a lot of buzz in the past few years, mostly because it is evidence that pre-moderns ventured into northern Eurasia very soon after their emergence in Africa. Here is a map from talk.origins which places it in perspective:

(if you click it you will see a larger image)

~1.8 million years ago there were many Homo and homo-like species hanging around on the scene. Remember those popular T-shirts which showed a linear sequence of species? Well, I’m not saying that modern humans are hybridized from branches of the bush (see here though on what might have happened). John Hawks scooped a press a few weeks ago (and knows more about this topic, obviously).

Hominid hacking

I’m sure you’ve heard about the very ancient pedigree of tuberculosis by now. Carl Zimmer has posted in depth on this topic already, so I’ll just point you there in case you want something more than the free PDF. Too often people imagine evolution as being driven out environmental change. My recent post which pointed to climate change is in keeping with this tradition. But in reality coevolution with other species, in particular pathogens, is a crucial factor which doesn’t get enough emphasis, even though the ‘Red Queen’ hypothesis is in the zeitgeist. Unfortunately, I think part of this is the tendency to imagine ‘fitness’ as something in relation to the elements around you, when what is really crucial is your reproductive rate in relation to conspecifics. This rate is strongly influenced by persistent infections (pathogens) as well as social interactions with other members of your species. The “environment” is outside, inside as well as the biases and emergent dynamics of the social group. Additionally, the parasite-hitchikers can give us phylogenetically relevant data points for palaeoanthropology, as tapeworms and lice have.

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Cultured Chimps

Some new research provides evidence that chimpanzees show ‘cultural conformity’: they follow the learned behaviour patterns prevalent in their group even though they are aware of effective alternatives. A report from the Guardian is here. There are several others on the net.

I think this could be important. Several experts on ‘cultural evolution’ have argued that conformism among humans is the result of selection between groups, but their only argument is that ‘there is no alternative’. They will now need to show that the same argument applies to chimps.

Added: to expand slightly on that last point, the group-selection theory requires that groups containing a genetic tendency towards cultural conformity should be more successful as groups than those which do not contain such a tendency. Among humans, this requirement is not implausible, because culture is obviously very important among humans, and because cultural traits vary widely among different groups. (Whether they vary widely among locally competing groups is more doubtful, but I won’t pursue that now.) Human groups also often act as groups, so that conformity might well be beneficial in inter-group competition.

It is not clear that the same can be said for chimps. Chimps do have some culturally acquired traits, and they do show some variation between different chimp populations. Notably, some populations use stones to crack nuts, and others don’t. But culture is far less developed among chimps than among humans, and it isn’t clear that cultural conformity would be likely to affect group survival among chimps in the way that the group selection theory would require. Of course, if conformity is beneficial to individuals, there is nothing for group selection to explain.

Update from Razib: Here is the article in Nature. Another in Scientific American. And finally, a release from Eureka Alert.

Fitch, Hauser and Chomsky respond to the response…..

I have posted on the “languages wars” before…so I thought that I’d point out that Noam Chomsky, Marc Hauser W. T. Fitch have responded (full text) to Steven Pinker and Ray Jackendoff’s paper which was written in response to their initial manifesto. Note that this is basically back-biting amongst the “innatist” camp as regards language. Though I think Pinker and Jackendoff have run ahead of the data as far as FOXP2 goes, I suspect their tack will be more fruitful. I am not necessarily one who believes that complex behaviors are necessarily straightforward adaptations or have strong fitness implications which can’t be warped or distorted by social considerations (even if a given religious practice is functionally deleterious, if it makes you an outcaste when you dissent from the practice then your fitness drops). But, I am highly skeptical that language is such a trait, I simply do not believe that serendipity is the source of our competence at speech (or recursive capacity).

Related: The children of Universal Grammar. FOXP2.

A tale of one ratchet

As some of you know, I am involved in the Cognitive Science Blog Reading Group where we are reading Michael Tomasello’s The Cultural Origins of Human Cognition. As I stated on the group I view my participation on the list and posts on the weblog as synergistic, intersecting but not necessarily coterminous activities. The core readership of this weblog is focused on the biological sciences, and so a post I make here will not have the same flavor as a comment I might make on the reading group, because the goal and shared lexicon differ. Unlike other group members I decided to read the book in two sessions and will give a short review of the whole book here. I do not know if I will post follow up posts because I will state beforehand that most of the book is way outside the core of my knowledge base, biological-evolutionary concerns are simply background assumptions that Tomasello does not engage with after an almost perfunctory nod in chapter 2 (even here he focuses more on ethology, the study of animal behavior, than on evolutionary biology or palaeoanthropology). If you want more details, you can always check in on Chris’ weblog where he will be commenting and linking copiously for weeks to come (I would characterize him as the John Hawks of cognitive science). Also, I will always update the “Related links” below with weblog posts that deal with the book indefinitely.

First, speaking directly to the audience of this weblog, I will offer a tangential digression about why I am interested in cognitive science. Though I had read Steven Pinker’s popular books years ago, my interest in the field was triggered primarily by my encounter with Scott Atran’s In Gods We Trust: The Evolutionary Landscape of Religion. I emphasized the evolutionary portion because I did not pick up that book with an understanding that it would be suffused with terminology and paradigms draw from cognitive science, rather, I was looking for a Darwinian account of the growth and development of what I perceive to be a human universal, religious expression. Engaging with Atran led me to other books like Explaining Culture by Dan Sperber and Religion Explained by Pascal Boyer. The jargon overhead in these books (especially Atran’s) can be quite high, so I was driven to read Mind Readings by Paul Thagard just so I could get the gist of the terms that assault you in a never ending stream. Cognitive science is in many ways (I feel) philosophy + experiments, and unfortunately that triggers a schema which sometimes casts a pall over my attitude, because fundamentally I am not particularly interested in philosophy as an ends (I read philosophy for its insight into historically important ideologies as well as a dictionary for comprehending what other people are saying). But, nevertheless, I think cognitive science has some direct relevance to many areas of the human sciences that I am interested in, and so that’s why I am still venturing into this strange territory.1 This was brought home to me by a concluding review chapter of Atran’s book where he addresses “mind blind” theories of human behavior, like sociobiology or group selection. Atran’s contention was that looking at humans as cognitive black-boxes and focusing on how they express their behavior, rather than how they perceive and conceive of the world around as well, is a theoretically hamstrung paradigm. I agree. To use an analogy, Dmitriy Mendeleev’s periodic table is very useful in its own way for categorization and conceptualizing the relations between the elements (ie; electronegativity, nobility, etc.), but one needed a genuine post-Daltonian atomic theory grounded on the quantum level to make great deductive strides (even octect rules get you only so far!). Similarly, common theses like “proverty leads to terrorism” can be easily empirically refuted (at least in its deterministic strong form), but to go on to address this issue in all its manifestations we need to examine the phenomenon on all of its various levels of organization, starting with the cognitive level (psychology and neuroscience), and working up to macrosocial analyses. Too often economists spit out correlations and regressions, foreign policy analysts often concoct ad hoc verbal models while sociologists and historians try to squeeze behavior into “grand theories” (ie; Marxism, Post-Colonialism, etc.) by looking at the higher order group trends, insteading of starting from the basic level of the individual.

So there is the manifesto, on to the book. As I stated above, this might be my only review because most of the chapters are simply outside of the core focus of my knowledge base. Though I’ve read spottily in cognitive science (and am an enthusiastic miner of paradigms from it), I don’t know much about developmental psychology, which is almost a background assumption beyond chapter 2. So I will touch upon the primary thesis and then go on to some biological implications and assumptions.

Tomasello makes a pretty bald and simple claim: there is basically one species-unique feature of our cognitive phenotype which is at the root of much of what differentiates us from other beasts, and that is our ability to conceive of conspecifics (other humans) as intentional agents like ourselves. This is the overarching necessary and sufficient condition that results in our humanity, our ability to empathize with others and model their behaviors. Of course, the ability to perceive other humans as intentional agents (goal directed) is irrelevant outside of a social matrix, so much of Tomasello’s arguments rests upon our intentional modelling capacity being unleashed in distributed networks of information, the “culture.” Individual acquisition of information via imitation and socialization leads to the cummulative “ratchet effect” of cultural evolution which results in our spieces’ many unique implied traits.

Since the author’s hypothesis rests on developmental psychology rather than evolutionary biology, neurobiology or palaeoanthropology, there are many reviews of literature relating to children and blocks and other people. As someone who has a positive affinity for children the descriptions were sometimes distracting because an experiment that recounts how a child pretends that a block is a plane by shouting “Vroom!!!!” induced a mental image of a cute toddler which broke my train of thought. Chapter 2, which ostensibly deals with biological points in favor of his thesis elucidates the differencess between chimpanzees and humans, in particular chimps and infants. Tomasello dismisses assertions of chimpanzee culture, at least in the way humans have culture which is rooted in instruction, imitation and accumulation of novel behaviors. He even implies at some point that part of the problem is that we tend to see intentionality in chimps where there mi
ght not be any intentionality (this is common in many fields, one might argue that Intelligent Design is the more prominent current example of this tendency). Tomasello suggests that even young infants tend to engage their parents in a way that chimpanzees simply do not, and offers that the way infants learn behaviors implies an understanding of intent and overall structure of interpersonal relations that chimpanzees have a difficult time conceiving of. For example, human infants and toddlers will often exactly mimic adults in a task even if it is less efficient than another method which is plainly obvious, while chimpanzee “mimics” tend to exhibit a lot more variation and are almost ad hoc in their “imitation.” Tomasello gives the example of a chimp mother rolling over a log to get at some ants. Her infant subsequently “copied” this behavior, but Tomasello suggests that many of these behaviors are not imitation as much as a parent adding more information to the infant’s data base, which it subsequently acts upon. Now that the infant chimp knows that ants are under the log, it will attempt to get at them, pushing the log out of the way just happens to be the easiest way to do this. In controlled experiments Tomasello points out that chimps often imitate in a scatter shot fashion that suggests that they are not fixed as much on the behavior of the chimp who serves as the model as opposed to the object of interest that the model chimp brings attention to via their behavior. Chimpanzees, in short, live in a world filled with moving animals (which includes other chimps, more or less) that might cause changes and display correlated behaviors, but they are not 3-dimensional Others who are worthy of understanding fundamentally, and, from whom one could learn.

In contrast to chimps, human infants around 9 months (though there are glimmers of species unique behavior before, especially in parent-child interactions) begin to behave in a fashion where other humans beings, as well as the object of attention, become important. In other words, the goals of other human beings and their motivations and tendencies as individuals like the infant itself become noticeable. Whereas before 9 months infants behave “dyadically,” that is, in a one-to-one interaction, as opposed to “triadically,” where there are multiple relations at work (usually involving the infant, another person, and an object). This ability to interact with other human beings as complex creatures with motives and intentions similar to one’s own is the beginning of the ontogenetic ratchet, as humans begin to develop toward a mature cognitive phenotype, developing verbal and cognitive sophistication gradually because of the saturation of social input enabled by the initial spark of intentional thinking. This ontegenetic ratchet is nested within the historical-cultural ratchet, where humans leverage each other’s information and spread memes throughout the population via instruction and imitation. Note that in The Meme Machine Susan Blackmore goes to great efforts to dismiss the idea that non-human creatures “really engage in imitation.” Some of Toamsello’s ideas are reminiscent of her arguments, though he focuses on the issues of “why” more than “how,” that is, humans imitate so well because they can conceive of others as intentional agents that one can learn from. Some of Judith Rich Harris’ talking points in The Nurture Assumption can also be slotted into Tomasello’s paradigm, though he focuses more on parent-child interaction while Harris is fixed on peer groups. To be human is to be social, and sociality is enabled by the intentional concept of others. When it comes to language, Tomasello pretty clearly rejects the idea that language is an innate module, and explicitly says that unlike many people he is skeptical that if everyone over the age of 1 became autistic, but still retained the ability to feed and care for children, language would “naturally” emerge out of the social matrix. Rather, Tomasello, argues that language is a cultural device generated by humans via their symbolic-representational aptitudes which are themselves an outgrowth of their facility with modelling intentional relations. There are similarities with Terrence Deacon’s ideas in The Symbolic Species, where much of the argument about language focuses on the thesis that language is simply a subset of the symbolic capacity and that “universal grammar” is just an artifact of the particular biases of the brain’s wiring which all “invented” languages slowly converged upon through cultural selection and pruning. If you replaced “intentional agents” with a more generalized “symbolic” capacity much of Tomasello’s argument matches that of Deacon’s, Tomasello asserts at one point that our models of physical objects are simply mappings of concepts which were initially relevant only to social interactions with conspecifics. While Deacon would argue for a general symbolic ability which can be applied in different contexts, Tomasello seems to argue for a general intentionalizing capacity which is abstracted toward a general symbolic ability.

This is not a conversational popular work, I am eliding a great deal and compressing Tomasello’s argument unfairly. But being a blog post, so it goes. Though a certain “Clark” seems to be referenced on every other page, I have no idea who this individual is, or the character of their life, as would be common in a popular work. Tomasello likely excised as much as possible from his argument to compress the prose into 216 pages, and I am not doing justice to the nuance of his argument, in part because I am not totally comfortable with terms like “intersubjectivity” or “perspectival.” While I am comfortable with “ontegeny” and other biologically intelligible terms, cognitive science jargon is still a third language for me. So I will move on now to the issues which I know a bit more about, the biological frame that Tomasello works within. He asserts that the capacity for humans to behave as intentional agents arose sometime between 6 million and 250,000 years ago, roughly the period between our last common ancestor with chimpanzees and the emergence of anatomically modern humans in Africa. This is a large window, and he doesn’t seem to want to get caught up with the details of when intentionality arose. Additionally, he argues against modularity of various cognitive phenotypes because 6 million years is not long enough for these to evolve. Finally, he throws in the point that 99% of our sequence is cognate with that of chimpanzees to argue that the genotypic difference is minimal. Tomasello emphasizes that it is development, ontegeny, which is at the heart of our differences with our nearest relatives.

First, I will point you to Bora Zivkovic’s post on the first chapter of Tomasello’s book. It is an understatement to assert that Bora and I have disagreed in the past, but as biologically oriented individuals it was no surprise to me that he basically asks the same questions that immediately came to my mind. Just as I find the Evolutionary PsychologicalTM argument that salient cognitive features must be monomorphic because of the importance of contingency (“half a trait is worthless,” a mutation inserted into the mechanistic epistatic network would result in a collapse of the cascade of pathways which result in the phenotype) an exaggeration contradicted by the reality of human variation on many traits, I find the argument that 6 million years isn’
t “enough time” for evolution to work upon variation to generate species specific modules unpersuasive. I don’t think the evidence is conclusive in either direction (calling all cognitive neuroscientists!), and evolution of phenotype does not proceed at a constant rate, but is contingent upon variation responding to selection (OK, at one locus, but I suspect it isn’t like selection on correlated traits is always at a steady pace). The amount of variation within a population and the magnitude of selection can both change a great deal over time, ergo, I don’t think that Tomasello’s assertion at the beginning of the book really holds. Palaeoanthroplogy tells us that there has been a persistent increase in cranial volume over the past 2 million years, ceasing about 200,000 years ago, and, this rate has not been constant (there were spurts here and there). Bruce Lahn’s recent work points to persistent directional selection on the genes which control for the size of the brain. There is also research which explores the matter of gene expression in the brain (vis-a-vi chimpanzees, for example). I don’t know whether it is the sequence or the expression that matters, but I certainly don’t think the question has been answered, and I don’t think that 6 million years is piddling (frankly, I don’t think a few hundred thousand years is piddling, depending on what traits you are talking about).

Though I am willing to grant that humans are unique insofar as they view others as intentional agents, and that this difference is one of the most important factors that generate our humanity, I think there are other issues that Tomasello gives short shrift to. For example, even if language started out as an emergent property of the social-informational complexity engendered by the ability to peceive others as intentional agents, I don’t see why the Baldwin Effect wouldn’t result in those who are able to be more linguistically eloquent having a selective advantage, so there was a shift toward innateness over time. Certainly, the fact that there is a “critical period” after which our ability to pick up language seems to dissipate suggests to me that our brain has been “retrofitted” toward “competence” for this phenotype. Additionally, Tomasello juxtaposes language with mathematics, and implies that the former is far more similar to the latter than we perceive it to be. Though I suspect bioengineering and cybernetics will make conventional selection moot soon enough, in some ways I think that mathematical fluency is a good model for what language must have been like before selection for competency on this ability allowed it to be a “natural” ability. The Number Sense chronicles many cases of “mathematical aphasia,” but these cases are usually much milder, more diffuse, and more spotty than the linguistic aphasia which are center stage in The Language Instinct (unlike linguistic aphasia, you might not even find out via casual conversation that somone simply lacks the ability to count, and in fact, casual conversation will in all probability yield a lot of false positives as far as mathematical aphasias go). That suggests to me that the coupling between a genetic substrate (either rooted in sequence or expression differences, doesn’t matter) and the phenotype is closer in language than in mathematics (which is a retrofit in its first stages and coopts many different areas of the brain in different people). And, since Tomasello’s book was published there are tentative signs that language can be “invented” in a very short time by those who are isolated from parental inputs.

Tomasello does acknowledge the possibility for a behavioral module here and there when the fitness impact is totally obvious (he cites David Buss’ hypothesis about jealousy for example). But his focus on developmental psychology tends to result in his neglect of many human abilities which seem to result from long term selection via “culture.” For example, in neurobiologist William Calvin’s latest book he points out that chimpanzees simply do not have the sensory-motor capacity to create tools, even to the sophistication of the Oldowan technology that erectus used between 2.5 and 1.5 million years ago. Perhaps the ability to view others as intentional agents resulted in symbolic thinking, which triggered ideas on how to use tools, but I suspect that these subsequent downstream developments almost certainly had a genetic impact, and resulted in additions to our “cognitive toolkit.” The relatively static progression of tool use, with periodic spurts, until about 50,000 years ago is also peculiar. Obviously the ratchet need not be constant…but in terms of technology, and it seems expression of symbolism, its rate of ascendence is highly erratic. Many have used this fact to argue that there was a genetic change that must have precipitated the technological-cultural revolution of the past 50,000 years. Some think that the selective sweep that occurred around 100,000 years ago (give or take tens of thousands of years!) on the FOXP2 “language gene” has something to do with it. Of course, selection doesn’t always occur how you’d expect, so evolution might have some more surprises for us.

After all this, I guess I can say that I’m not convinced by Tomasello’s argument. I think he has found an essential cog in the whole artiface of humanity, but it isn’t the master-cog. I’m not really sure there is a master-cog. There is evidence of both sequence changes and alterations in gene expression in reference to the human brain. It seems clear that selection occurred on our sensory-motor capacities that resulted in our competence in reference to tool use…but obviously, it seems strange that this would develop before we used tools, so why did we starting using tools a few million years ago anyhow? FOXP2, which is a regulatory gene that has some relevance to language fluency, as well as general intelligence, swept through our species a hundred thousand years ago, or earlier. Symbolic culture seems to have really taken off less than 100,000 years ago. This is a really knarly bush of theoretical contingencies and possibilities, and Tomasello has evaded the biological ones by simply moving past them very quickly. If I had to bet, I would guess that the ability to view each other as intentional agents is relatively recent, perhaps within the last few hundred thousand years. I do think it is a crucial change in our conception of the world, but, I believe it also set into motion changes which resulted in other selective forces being unleashed, and language arose as a competency in its wake. Our ability to use tools and manipulate physical objects in a complex manner though preceded the intentional mind, and in fact might have somehow set the stage for selection for this trait. Perhaps Tomasello has it backward, and somehow we began to imagine other huma
n beings as tools, to be shaped and bent to our own uses. If my timeline is right the major push toward expansion of the human cranium and selection on those loci which affect brain size occurred before the major switch in our conception of the world.

The Cultural Origins of Human Cognition is a very good book. It is a bit dense if you are a cognitive science virgin, but if you’ve made it only to first or second base (like me) it won’t offend your sensibilities and tax your level of expertise too much. It reinforces some points I have made many times on this weblog, for instance, that children learn many ostensibly cause-and-effect conceptual structures through imitation, that their causative nature is only apparent to the initiated and culturally fluent. Etiquette is a clear example, you behave like so because to not behave like so is “rude,” but as we all know, why it is rude is not always easy to pinpoint (or, that’s what I claim!). Ultimately, rudeness is often based on social deviation. The conception of others as intentional agents worthy of some empathy and consideration is certainly very important. But I doubt it is the whole story by a longshot, and I would take bets on that. But it is a big enough story that it deserves a lot of attention.

Related links: Cultural Origins of Cognition: Introduction and Context, and intro at Chris’ weblog. Clark on chapter 1. Jesse riffing off Clark. Bora on chapter 1. Blar on Santayana and Tomasello. Chris on chapter 1. Here is a paper that comes close to being a precis for the book, and a recent paper which tests some of his hypotheses. A piece in Scientific American reports on research published in Nature which directly contradicts Tomasello’s assertion that chimpanzees do not have imitative culture. Of course, the conclusion is up for dispute, but the quote at the end explicitly rejects the thesis that it was attention to the goal rather than the task itself that the chimps were focused on. Chris has a post on autism that readers might find interesting. Chris on chapter 2. Clark with chatper 1 bonus.

Related on this blog: Dusk of Human Culture, The Mating Mind, Grooming and Gossip and Mother Nature.

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1 – I won’t deny that philosophy also has relevance on higher orders, but I feel that “philosophy of….” fields are often too detached from the discipline they are devoted to analyzing (ie; science, religion, history, etc.).