Saturday, April 5, 2014

The riddle of Microcephalin


 
World distribution of the recent Microcephalin allele. The prevalence is indicated in black and the letter 'D' refers to the 'derived' or recent allele (Evans et al., 2005)
 

Almost a decade ago, there was much interest in a finding that a gene involved in brain growth, Microcephalin, continued to evolve after modern humans had begun to spread out of Africa. The 'derived' allele of this gene (the most recent variant) arose some 37,000 years ago somewhere in Eurasia and even today is largely confined to the native populations of Eurasia and the Americas (Evans et al., 2005).

Interest then evaporated when no significant correlation was found between this derived allele and higher scores on IQ tests (Mekel-Bobrov et al, 2007; Rushton et al., 2007). Nonetheless, a later study did show that this allele correlates with increased brain volume (Montgomery and Mundy, 2010).

So what is going on? Perhaps the derived Microcephalin allele helps us on a mental task that IQ tests fail to measure. Or perhaps it boosts intelligence in some indirect way that shows up in differences between populations but not in differences between individuals.

The second explanation is the one favored in a recent study by Woodley et al. (2014). The authors found a high correlation (r = 0.79) between the incidence of this allele and a population's estimated mean IQ, using a sample of 59 populations from throughout the world. They also found a correlation with a lower incidence of infectious diseases, as measured by DALY (disability adjusted life years). They go on to argue that this allele may improve the body’s immune response to viral infections, thus enabling humans to survive in larger communities, which in turn would have selected for increased intelligence:

Bigger and more disease resistant populations would be able to produce more high intelligence individuals who could take advantage of the new cognitive opportunities afforded by the social and cultural changes that occurred over the past 10,000 years. (Woodley et al., 2014)

Bigger populations would also have increased the probability of “new intelligence-enhancing mutations and created new cognitive niches encouraging accelerated directional selection for the carriers of these mutations.” A positive feedback would have thus developed between intelligence and population density:

[…] the evolution of higher levels of intelligence during the Upper Paleolithic revolution some 50,000 to 10,000 ybp may have been necessary for the development of the sorts of subsistence paradigms (e.g. pastoralism, plant cultivation, etc.) that subsequently emerged. (Woodley et al., 2014)
 
 
What do I think?

I have mixed feelings about this study. Looking at the world distribution of this allele (see above map), I can see right away a much higher prevalence in Eurasia and the Americas than in sub-Saharan Africa. That kind of geographic distribution would inevitably correlate with IQ. And it would also correlate with the prevalence of infectious diseases.

Unfortunately, such correlations can be spurious. There are all kinds of differences between sub-Saharan Africa and the rest of the world. One could show, for instance, that per capita consumption of yams correlates inversely with IQ. But yams don't make you stupid.

More seriously, one could attribute the geographic range of this allele to a founder effect that occurred when modern humans began to spread out of Africa to other continents. In that case, it could be junk DNA with no adaptive value at all. There is of course a bit of a margin between its estimated time of origin (circa 37,000 BP) and the Out of Africa event (circa 50,000 BP), but that difference could be put down to errors in estimating either date.

No, I don't believe that a founder effect was responsible. A more likely cause would be selection to meet the cognitive demands of the First Industrial Revolution, when humans had to create a wider range of tools to cope with seasonal environments and severe time constraints on the tasks of locating, processing, and storing food. This allele might have helped humans in the task of imagining a 3D mental “template” of whatever tool they wished to make. Or it might have helped hunters store large quantities of spatio-temporal information (like a GPS) while hunting over large expanses of territory. Those are my hunches.

I don't want to pooh-pooh the explanation proposed in this study. At times, however, the authors' reasoning seems more than a bit strained. Yes, this allele does facilitate re-growth of neural tissue after influenza infections, probably via repair of damaged DNA, but the evidence for a more general role in immune response seems weak. More to the point, the allele’s time of origin (39,000 BP) doesn't correspond to a time when humans began to live in larger, more sedentary communities. This was when they were still hunter-gatherers and just beginning to spread into temperate and sub-arctic environments with lower carrying capacities. Human population density was probably going down, not up. It wasn't until almost 30,000 years later, with the advent of agriculture, that it began to increase considerably.

The authors are aware of this last point and note in it their paper. So we come back to the question: what could have been increasing the risk of disease circa 39,000 BP? The authors suggest several sources of increased risk: contact with archaic hominins (Neanderthals, Denisovans), domestication of wolves and other animals, increasing population densities of hunter-gatherers, and contact by hunter-gatherers with new environments. Again, this reasoning seems to push the envelope of plausibility. Yes, Neanderthals were still around in 39,000 BP, but they had already begun to retreat and by 30,000 BP were extinct over most of their former range. Yes, we have evidence of wolf domestication as early as 33,000 BP, but livestock animals were not domesticated until much later. Yes, there was a trend toward increasing population density among hunter-gatherers, but this was not until after the glacial maximum, i.e., from 15,000 BP onward. Yes, hunter-gatherers were entering new environments, but those environments were largely outside the tropics in regions where winter kills many pathogens. So disease risk would have been decreasing.

I don’t wish to come down too hard on this paper. There may be something to it. My fear is simply that it will steer researchers away from another possible explanation: the derived Microcephalin allele assists performance on a mental task that is not measured by standard IQ tests.

 
References 

Evans, P. D., Gilbert, S. L., Mekel-Bobrov, N., Vallender, E. J., Anderson, J. R., Vaez-Azizi, L. M., et al. (2005). Microcephalin, a gene regulating brain size, continues to evolve adaptively in humans, Science, 309, 1717-1720.
http://www.fed.cuhk.edu.hk/~lchang/material/Evolutionary/Brain%20gene%20and%20race.pdf  

Mekel-Bobrov, N., Posthuma, D., Gilbert, S. L., Lind, P., Gosso, M. F., Luciano, M., et al. (2007). The ongoing adaptive evolution of ASPM and Microcephalin is not explained by increased intelligence, Human Molecular Genetics, 16, 600-608.
http://psych.colorado.edu/~carey/pdfFiles/ASPMMicrocephalin_Lahn.pdf  

Montgomery, S. H., and N.I. Mundy. (2010). Brain evolution: Microcephaly genes weigh in, Current Biology, 20, R244-R246.
http://www.sciencedirect.com/science/article/pii/S0960982210000862  

Rushton, J. P., Vernon, P. A., and Bons, T. A. (2007). No evidence that polymorphisms of brain regulator genes Microcephalin and ASPM are associated with general mental ability, head circumference or altruism, Biology Letters, 3, 157-160.
http://semantico-scolaris.com/media/data/Luxid/Biol_Lett_2007_Apr_22_3(2)_157-160/rsbl20060586.pdf  

Woodley, M. A., H. Rindermann, E. Bell, J. Stratford, and D. Piffer. (2014). The relationship between Microcephalin, ASPM and intelligence: A reconsideration, Intelligence, 44, 51-63.
http://www.sciencedirect.com/science/article/pii/S0160289614000312  

45 comments:

Anonymous said...

the evolution of higher levels of intelligence during the Upper Paleolithic revolution some 50,000 to 10,000 ybp may have been necessary for the development of the sorts of subsistence paradigms (e.g. pastoralism, plant cultivation, etc.) that subsequently emerged.

Tutsis and Maasai are pastoralists; many sub-Saharan African cultures are agriculturalists. So that's definitely not the reason this gene is needed.

However, larger scale social organization like cities or seriously planning ahead for a harsh winter might require different behaviors than are observed in Africa.

JayMan said...

Oh I'm sure they'll be more than few comments in defense of this.

It seems to fall victim to a fundamental tenet of science: correlation is not causation.

That said, there may be something to this, but we'll see.

Interestingly, I've noticed more than a few modern researchers embracing older Lynn-Ruston ideas on the evolution of modern peoples: that modern average IQ and behavioral traits evolved in the Pleistocene as a response to Ice Ages and such. Never mind that many modern peoples aren't even descended by in large, from the Ice Age hunter-gatherer populations that reside where moderns do now. Never mind that the rate of evolution increased substantially since the onset of agriculture. Never mind that actual hunter-gatherers living in Arctic areas (e.g., the Inuit) are quite unlike peoples from advanced civilizations.

Certainly, some selection had taken place during this time. But many of the differences between modern peoples, such as differences in average IQ or behavioral traits, are the result of more recent selection.

It doesn't seem to do any good to hold on to outdated and now obviously implausible ideas, it seems.

Sean said...

I make an awful lot of silly mistakes. Still, as I read it the prevalence is greatest in southern Amerindians and north Chinese a bit less in Europeans, and low in the cradle of civilisation around the Iraq area, rather high in Melanesia, and very low in black Africans.

In the 'Population differences in intellectual capacity: a new polygenic analysis' post the other month it said Piffer found alleles that are apparently related to a single factor and increase intellectual capacity. The average prevalence was 39% among East Asians, 36% among Europeans, 32% among Amerindians, 24% among Melanesians and Papuan-New Guineans, and 16% among sub-Saharan Africans."

I doubt Melanesians are any smarter than black Africans. So the derived alleles Piffer found may not be for anything like IQ. More certainly, the derived microcephalin allele is likely for something unrelated to hunting or workmanlike attributes. My bet is the recent microcephalin allele relates to language. Melanesia is known for having a vast number of languages, and that has been related to group selection.

Europeans' metal attributes have much to do with their extremely low prenatal testosteronisation, in my opinion. The lateralization of mens' frontal lobe functions is different than womens.

Rather that genes of big effect, IQ was largely selected for by soft sweeps (through I'm not quite sure what that means).

Anonymous said...

"The riddle of Microcephalin"

Steel isn't strong; microcephalin is stronger.

Anonymous said...

I might put more stock in this study were it not for the fact that it relies so heavily on data from Richard Lynn, whose work has been widely criticized, even by other hereditarians.

Particularly perplexing is the fact that the IQ scores Lynn reports for sub-Saharan Africans are as far below African Americans as they are below US whites. Of course, everyone knows that American blacks average about 20 percent European admixture. But that would surely not be expected to close the starting IQ gap halfway - unless there was vigorous selective pressure in favor of greater intelligence on American soil over the past 400 years.

The bottom line is that if one accepts the 70 figure for black Africa and the 85 figure for African Americans as equally valid, one is obliged to posit some hereditary mechanism by which this boost took place. It's unfortunate that Woodley et. al. don't seem to include African Americans in their survey. So we can't tell if they have a higher incidence of these Microcephalin alleles than one would expect on the basis of admixture alone. Such a finding, if it could be demonstrated, would be highly suggestive, both of recent New World evolution and of a causal link between microcephalin and intelligence.

Alas, as it stands, this kind of study has many vagaries and runs great risk of circular reasoning.

Sean said...

wasor"But that would surely not be expected to close the starting IQ gap halfway".

Nobody knows enough to expect that or anything else. Anomalies are never lacking in any scientific theory of the past, present or future. Almost certainly there are huge surprises, and researchers (including Lynn) will have their reputations going up and down over time. Lynn may be right or wrong for reasons still to be established. African American IQ may be affected by the mothers of the original mixture being almost entirely black (as I'm obliged to posit some hereditary mechanism).

Anonymous said...

Functional divergence of the brain-size regulating gene MCPH1 during primate evolution and the origin of humans

http://www.biomedcentral.com/1741-7007/11/62

Peter Fros_ said...

Anon,

Actually, this is one point where I agree with the authors. The "First Industrial Revolution" of the Upper Paleolithic pre-adapted the humans of northern Eurasia for later cultural developments, not so much agriculture but rather the advent of more complex technologies and forms of social organization.

Jayman,

I'm opposed to unified theories of everything, and I agree that selection has been an ongoing process that didn't stop in the Upper Paleolithic. But I think it's significant that, if we look at derived alleles associated with intelligence, Arctic hunter-gatherers seem to occupy a position midway between other hunter-gatherers and more advanced populations.

Sean,

Piffer's genes have been shown to influence intellectual capacity. They're not a black box like Microcephalin.

Anon,

African American IQ has been overestimated. It is probably closer to 82 than 85. This is because of a sampling bias that favors subjects who will sit in a classroom and do an IQ test.

African IQ is probably higher than earlier thought. I don't have the reference at hand, but I remember reading a recent study that challenged Lynn's findings.

Anonymous said...

Interestingly, I've noticed more than a few modern researchers embracing older Lynn-Ruston ideas on the evolution of modern peoples: that modern average IQ and behavioral traits evolved in the Pleistocene as a response to Ice Ages and such. Never mind that many modern peoples aren't even descended by in large, from the Ice Age hunter-gatherer populations that reside where moderns do now. Never mind that the rate of evolution increased substantially since the onset of agriculture. Never mind that actual hunter-gatherers living in Arctic areas (e.g., the Inuit) are quite unlike peoples from advanced civilizations.

Never mind that the "older Lynn-Rushton ideas" haven't really been seriously invalidated or challenged. Never mind that idea that the rate of evolution has increased substantially with agriculture doesn't necessarily invalidate the "older Lynn-Rushton ideas". Never mind that the modern populations with the highest IQs tend to have relatively more Ice Age H-G ancestry. Never mind that modern populations descended from the oldest civilizations such as Mesopotamia, the Nile Valley, the Indus Valley, etc. tend to have low IQs. Never mind that there are good reasons to believe that civilization is or can be quite dysgenic.

Anonymous said...

Amerindians have long puzzled me. They have high quantities of the Microcephalin allele. They have high cephalic indexes. Those other seven alleles Piffer studied which affect cognitive ability have an average prevalence of 32% among Amerindians, which compares favorably with the European average of 36%.

It might be tempting to dismiss this all with some alternative explanation, except we know that Amerindians were, at one point, an intellectually capable population: the accomplishments of the Aztecs, Mayans, Toltecs, and Incas were indeed impressive considering they were sundered from the rest of humanity and faced numerous environmental handicaps. They definitely outclassed sub-Saharan Africans, Abos, Papuans, SE Asians like Indonesians and Filipinos, and certain other groups.

I recall that Richard Lynn once admitted that the largest study of Amerindian IQ yielded an average of 94, but he dismissed that number without any valid reason. That IQ was for unmixed Amerindians too, not Mestizos. It does make you wonder.

M said...

In the 'Population differences in intellectual capacity: a new polygenic analysis' post the other month it said Piffer found alleles that are apparently related to a single factor and increase intellectual capacity. The average prevalence was 39% among East Asians, 36% among Europeans, 32% among Amerindians, 24% among Melanesians and Papuan-New Guineans, and 16% among sub-Saharan Africans."

Sean, yes, the Papuans and Australian Aborigines are a very important population to truly understand African-Eurasian differences.

They fact they have high frequencies of various skin lightening (ASIP) and putative IQ enhancing genetics ascertained in West Eurasians and Africans, despite being more or less as dark and as low scoring on tests of IQ as West Africans should cause some pause in how we interpret these genes.

Handling Australian Aborigine (and Tongan) political relations with respect, and so being able to do the kind of even rudimentary mapping that Americans have done with admixed Africans populations and will soon do with Latinos would be very, very interesting, if the Aussies could achieve it (the Aussies get called notorious racists all the time, yet I'm hopeful they could).

By the way, Peter, do you have any comments on the recent paper on modelling face shape differences, using an African-European admixture cline as a basis to discover traits (by being able to control for "family" structure on a large scale)-

http://www.plosgenetics.org/article/fetchObject.action?uri=info:doi/10.1371/journal.pgen.1004224.g003&representation=PNG_I

The facial shape genetics of large effect they've found (all listed in the supplement) that contribute to Europeans and African variation don't seem to involve sex hormones (differences in genes contributing to production or response of sex hormones).

However, they have separated masculinity-femininity completely from the European-African facial dimension here (so the European-African facial dimension is "net" of differences in masc-fem, whatever they may be). And also they have checked for differences in genes known to be involved in facial dysmorphology, specifically, which could exclude genes which influence facial sex.

Particularly perplexing is the fact that the IQ scores Lynn reports for sub-Saharan Africans are as far below African Americans as they are below US whites. Of course, everyone knows that American blacks average about 20 percent European admixture. But that would surely not be expected to close the starting IQ gap halfway - unless there was vigorous selective pressure in favor of greater intelligence on American soil over the past 400 years.

I think Cognitive Ability Tests (basically IQ tests) for African children in Britain on large batteries of children tend to give both them and Jamaicans equally just under a half standard deviation "deficit" from Whites.

Slightly better than ethnic Irish Travellers and the Roma, and better than Aframs seem to. There could be an "elite" aspect (either Africans being elite or being average Africans and thus slightly more capable than the offspring of slaves and po' whites).

http://akarlin.com/2012/08/minorities-cognitive-performance-in-the-uk/

Sean said...

[Piffer's genes] "shown to influence intellectual capacity".

In England children who do not speak English at home exceed half of the indigenous working class. On the other hand children for whom test results are reported are not representative because there are a lot of special education social exclusion units in London now. Immigration is a family investment and something that only the relatively wealthy can do until the diaspora communities reach a size that ameliorates the various costs. Africans in London are just the the early waves who have needed to have had a bit of money to invest in migrating. So they are probably from families that are well above their homeland's average.

On the basis of Piffer's data or even derived ASPM prevalence indicating some related quality, the average African should be, if anything, less intelligent than Lynn's assessment.

Sean said...

A while back I got criticised for talking about genetic mixing of Africans (mainly the males) and Europeans happening faster than anyone thought possible.

Some reality therapy. Minorities’ Cognitive Performance In The UK "What I take to be a fairly representative sample of Britain’s school-age population – the proportion of British Whites is 82%, and the share of overall Whites is slightly less than 85%; mixed people are about 3%. For comparison, British Whites constituted 86% of the population (in 2001), while only 64% of children born in 2005 where recorded as British Whites. Seems like a very fast rate of population replacement."

It's mainly the black male white female pairings as I thought. 20% of births to Polish women in England have black fathers.

Sean said...

Source.

Anonymous said...

Sean, you misunderstand the statistic given in the article you cited.

"Most of the 21,000 children born to Polish mothers in 2012 had Polish fathers; but of the rest, 23% had African or Asian fathers."

That means that out of the ones who didn't have a Polish father, 23% had an African or Asian father. It does not mean that 23% of the total children born to Polish women had one.

Stephen said...

Not many IQ test test memory much. Eskimos where found to be very good at spot the difference even though they weren't that great at other IQ tests.

Ben10 said...

Regarding IQ involvement in spatial/3d recognition and memorization, there are some weird facts to contemplate.
First, observe the Lascaux figures (now retrograded to around 18000 years old, correct me if I am wrong), some of the drawings of animals are slightly out of proportions, but most show a remarkable rendering of images on stones (i.e., 3d mental projection on a 2d support). The animals body parts and anatomy are rendered with near perfect proportions. That suggests a good mental representation of 3d space, which, beside drawing, was probably useful for hunting long distances.
The sculpted statuettes are not bad either. They are sometimes stylized, but never with wrong proportions or anatomically misshaped.
Yet, these populations were replaced by Celts . And now its a disaster. Celtic art of sculpting and drawing has its qualities, but compared to the Cro-Magnon it's way below. Human and animal figures are anatomically out of proportions, sometimes with gross anatomic misshapes. For example, a horse sculpted in semi relief on a cauldron had his forelegs drawn backward.
That suggest these populations didn't have the tridimensional mental representation capabilities of their predecessors, and yet were able to replace them.
Celtic art improves only under the influence of Greek and Roman artwork.
Then comes the Germans: it's not much better than the Celts initially in my opinion, and therefore still way inferior to the Cro-Magnon. Just look at any Medieval gravure to see that perspective sucks and the sense of anatomy is lost again. So, where have been the late skills acquired by the Celts in contact with antique art, lost?
We have to wait to the late middle age and renaissance to see perspective and anatomically correct representations again.

So, what does it says about visual IQ in general?
There is a genetic component without any doubt. Some people can't draw, some can. I am an excellent drawer without any special education or background, by birth I should say. Certainly a genetic search should find predisposing genes, or gene pool.
But most importantly, the thing is that in no way a high 'visual IQ' is a guaranty of any reproduction success or population survival in general, as has history, or prehistory shown.

What about IQ in other tasks? Well, usually people's IQ is tested in a quiet place, belly full, sitting comfortably. Some tests should be done under the stress of combat, starvation, after running long distance etc.
Then we may have a better idea of what IQ genes such as Microcephalin are doing.

A big issue to me is to see how the IQ varies under long term undernourishment, as the brain is so power hungry. High IQ brains may fall very hard and low under these circumstances. Perhaps the role of some genes is just to maintain a decent IQ under sub-optimal conditions by a better control of the brain energetic consumption.

Sean said...

Approximately 25% non-Polish father Polish mother births, 'only' around 20% of those have black fathers.

'Caribbean' children in Britain may include quite a few with a white parent or grandparent. Half Carribean men who are part of a couple are not with a black woman.

Mirco Romanato said...

Maybe microcefalin variant gene correlate to larger brain just because larger brains/head are more useful in cold climates than smaller brains and smaller heads.

The volume/surface ratio would be better for people with larger brains/heads. This could have some impact on survival ratios.

Exposition to cold can impair thinking. And this could have a profound effect on people not already adapted to cold environments in other ways.

Sean said...

You would have to be pretty far gone to not be able to think straight. I would think natural selection works to turbocharge thinking when we are cold and hungry.

Sean said...

You would have to be pretty far gone to not be able to think straight. I would think natural selection works to turbocharge thinking when we are cold and hungry.

Mirco Romanato said...

Natural selection just selected for people lasting more time in cold. The other died/never reproduced as fast as the cold resistant.

This is a citation found online
http://www.ski-adventure-guide.com/hypothermiasymptom.html

Medium Hypertermia

"The brain function starts to come up with symptoms of its own.These present themselves by absent mindedness, becoming confused, having short term memory problems.This single hypothermic symptom alone explains why snow expedition victims become lost, even in terrain which is familiar to them."

And this is talking about people able to use clothes made in the last couple of centuries and already pre adapted in many ways (like the hunter/gathers eating meat rich diets able to produce more heat discussed in a previous OP by Peter Frost).

Anonymous said...

Natural selection just selected for people lasting more time in cold. The other died/never reproduced as fast as the cold resistant.

There are different ways to "lasting more time in cold" and being "cold resistant". Both polar bears and eskimos live in the cold, but they obviously do so in quite dramatically different ways.

Humans expanded into cold climates relatively quickly and appear to have adapted primarily through mental, behavioral, and cultural means rather than through more physiological means such as thick blubber and fur coats which would have taken much longer to evolve.

Anonymous I said...

"Never mind that there are good reasons to believe that civilization is or can be quite dysgenic."

Aha! Tip of the hat to you, Anonymous.

Sean said...

"Or it might have helped hunters store large quantities of spatio-temporal information (like a GPS) while hunting over large expanses of territory."

Selection for division of labour so only men were mentally equipped to navigate while hunting could explain the sex linking I suppose. Sounds like what Christopher Badcock talks about with mechanistic thinking being male and mentalistic being female. Hence women are protected from autism. Interpretation of individual genes as having a simple relationship to things like reading looks like overreaching, because it's difficult difficult to separate their effects. Helen Keller learned to lip read by touch. Genetic redundancy
-------------
Higher protein intake increases thermogenesis. I think hunter gatherer mitochondria that specialised in burning food energy may not have mattered while lots of protein was available in a hunting diet. But on switching to farming, with a lower quality and quantity of protein along with frequent famines, such mitochondia may have been maladaptive.

Ben10 said...

Wiki explains the source of Microcephalin in non-sub-Saharan populations as a result of a possible introgression of Neanderthal genes in Moderns.
http://en.wikipedia.org/wiki/Microcephalin

But so far the allele has not been found in reconstructed Neanderthal genomes.
However, I would expect a significant genetic divergence (drift) in their isolated populations since they had much more time to drift away than Moderns. There should be many small subpopulations of Neanderthals with significant genetic variation, perhaps some with Microcephalin and some without, and we just have not sequenced the ones with it, yet.

Any ideas?

Anonymous said...

"The definitive study of race differences in brain size was carried out on approximately 20,000 crania by Professor Kenneth Beals and his colleagues at Oregon State University. Their results for endocranial volume, measured in cubic centimeters for the major races were as follows:

North East Asians (Chinese, Japanese and Koreans): 1,416 cm;
Europeans: 1,369cm;
Native American Indians: 1,366cm;
Southeast Asians: 1,332cm;
Pacific Islanders: 1,317cm;
South Asians: 1,293cm;
Sub-Saharan Africans: 1,282cm
Bushmen: 1,270cm;
Australian Aborigines: 1,225cm"

"..the positive association between brain size and intelligence in humans has been shown in numerous studies beginning in the first decade of the 20th century. Professor Philip A. Vernon of the University of Western Ontario and his colleagues have summarized studies of the correlation between intelligence and head size, and the correlation between intelligence and the size of the brain itself. Every one of 54 studies that measured head size showed a positive relationship, with an overall correlation of 0.18. Research using CT (computerized axial tomography) and MRI (magnetic resonance imaging) gives a more accurate measure of brain size, and the 11 studies that used these methods found an overall correlation with intelligence of 0.40. Prof. Vernon and his colleagues conclude that brain size must be a determinant of intelligence because larger brains have more neurons and this gives them greater processing capacity."

Sean said...

Right, so why did the Chinese never dominate world history like the Europeans. Europeans must have something an analysis such as Piffer's doesn't pick up. And it isn't Microcephalin.

JB said...

Some of the largest cranial capacities have been found among certain Polynesians like the Hawaiians.

I recall having a conversation with a young lady from Sicily about the large cranial capacity of Hawaiians and how it was a shame they didn't have more of Hawaii to reserved to maintain their linage. She objected that intelligence isn't correlated with brain size (she had, incidentally, a rather small cranial capacity for her size). I was quick to state that the exact opposite might be the case under some circumstances since, as has been shown in computer architecture, the region of control (the amount of space that signals must traverse in a clock cycle) is minimized in order to maximize computation flexibility (take branches, etc.). I also added that brain size might have some unknown function for organisms that must navigate the oceans -- such as cetacea and, of course, Hawaiians. That shut her up. It probably would have down-right scared Boas, Gould et al.

Sean said...

The point is the Chinese have large cranial capacity and (as the Population differences in intellectual capacity: a new polygenic analysis post shows) alleles for higher intellectual capacity are 3% higher in East Asians than in Europeans. That is quite comparable to the 4% more that Europeans have on Amerindians. Yet Europeans, not not Chinese, invented the modern world.

JB said...

It's not clear what exactly the relationship between greater brain size and intelligence is. It may have something to do with navigation ability. Peter has suggested something similar about Arctic peoples who have to traverse large areas. It's also not clear what exactly the relationship between greater inventiveness and intelligence is. Presumably they're related, but it's not clear that they're identical. Beavers, for example, have more impressive artifacts than cetaceans, but we are told that cetaceans are more intelligent. Inventions are high leverage phenotypes that enable you to leapfrog more basic genetic adaptation. Presumably the ultimate intelligence, as in traditional characterizations of the omniscient God, would just immediately "know" and intuit reality, without intervening artifacts such as deduction, experimental tools, inductive experiments, etc.

Sean said...

Whatever the relationship between brain size and IQ, Chinese have as big brains and as high IQ as any European group (Germans say).

In the capacity to concentrate attention for an extended period of time (a major factor in intellectual achievement, but not obviously useful outside civilisation) I would say Chinese are clearly superior to everyone else.

Ben10 said...

"In the capacity to concentrate attention for an extended period of time (a major factor in intellectual achievement, but not obviously useful outside civilisation) I would say Chinese are clearly superior to everyone else."

Within the occidental word (whatever it means these days), that's a result of the education system IMO.
At the time I was 'subbing' in the US public school, I found that this stereotype of the over-performing Asian student is strong among the students themselves. I met another 'sub', former teacher in India, who told me she couldn't teach full time in these schools loaded with chaos and attention deficit. She said: "In India I had classes of seventy (!) students and you could hear a pencil falling on the floor".
The country that send men on the Moon 45 years ago, without the help of any significant 'Asian skilla' is now starving for these educated workers from Asia. But it could be different. The US could produce all the skilled techs it needs, if it really wanted.
But it doesn't want to, my bet is that it is too convenient for the 'establishment', who can find here a good reason to explain why 'We need Immigration'.
High skilled workers to fill the jobs Americans can't do, in addition to Low skilled workers to fill the jobs Americans don't want to do.
A lot is theater in America, but the show must go on.

Anonymous said...

I find it very very unlikely that India's education system or classrooms outclasses America in any respect. The Indian diaspora has a tendency to exaggerate the potential of their country. Not only is India as a country overrated -- it'll never seriously compete with China or America or even Russia -- but I'm starting to believe their much vaunted upper castes are overrated as well.

India is a joke. Maybe if there were world rankings for gang rape or public defecation or empty boasting or unjustified arrogance, they'd take the top spot. Not in any other field though.

Anonymous said...

Here's an overview of some of the "talent" the Indian education system is producing:

http://online.wsj.com/news/articles/SB10001424052748703515504576142092863219826

BANGALORE, India—Call-center company 24/7 Customer Pvt. Ltd. is desperate to find new recruits who can answer questions by phone and email. It wants to hire 3,000 people this year. Yet in this country of 1.2 billion people, that is beginning to look like an impossible goal.

So few of the high school and college graduates who come through the door can communicate effectively in English, and so many lack a grasp of educational basics such as reading comprehension, that the company can hire just three out of every 100 applicants.

India projects an image of a nation churning out hundreds of thousands of students every year who are well educated, a looming threat to the better-paid middle-class workers of the West. Their abilities in math have been cited by President Barack Obama as a reason why the U.S. is facing competitive challenges.

Yet 24/7 Customer's experience tells a very different story. Its increasing difficulty finding competent employees in India has forced the company to expand its search to the Philippines and Nicaragua. Most of its 8,000 employees are now based outside of India.

In the nation that made offshoring a household word, 24/7 finds itself so short of talent that it is having to offshore.

With India's population size, it should be so much easier to find employees," says S. Nagarajan, founder of the company. "Instead, we're scouring every nook and cranny."

India's economic expansion was supposed to create opportunities for millions to rise out of poverty, get an education and land good jobs. But as India liberalized its economy starting in 1991 after decades of socialism, it failed to reform its heavily regulated education system.

Business executives say schools are hampered by overbearing bureaucracy and a focus on rote learning rather than critical thinking and comprehension. Government keeps tuition low, which makes schools accessible to more students, but also keeps teacher salaries and budgets low. What's more, say educators and business leaders, the curriculum in most places is outdated and disconnected from the real world.

"If you pay peanuts, you get monkeys," says Vijay Thadani, chief executive of New Delhi-based NIIT Ltd. India, a recruitment firm that also runs job-training programs for college graduates lacking the skills to land good jobs.

Muddying the picture is that on the surface, India appears to have met the demand for more educated workers with a quantum leap in graduates. Engineering colleges in India now have seats for 1.5 million students, nearly four times the 390,000 available in 2000, according to the National Association of Software and Services Companies, a trade group.

But 75% of technical graduates and more than 85% of general graduates are unemployable by India's high-growth global industries, including information technology and call centers, according to results from assessment tests administered by the group.

Another survey, conducted annually by Pratham, a nongovernmental organization that aims to improve education for the poor, looked at grade-school performance at 13,000 schools in rural areas in India, where more than 70% of the population resides. It found that about half fifth graders can't read at a second-grade level in India.

At stake is India's ability to sustain growth—its economy is projected to expand 9% this year—while maintaining its advantages as a low-cost place to do business.

Anonymous said...

The challenge is especially pressing given the country's more youthful population than the U.S., Europe and China. More than half of India's population is under the age of 25, and one million people a month are expected to seek to join the labor force here over the next decade, the Indian government estimates. The fear is that if these young people aren't trained well enough to participate in the country's glittering new economy, they pose a potential threat to India's stability.

...

"I was not prepared at all to get a job," says Pradeep Singh, 23, who graduated last year from RKDF College of Engineering, one of the city of Bhopal's oldest engineering schools. He has been on five job interviews—none of which led to work. To make himself more attractive to potential employers, he has enrolled in a five-month-long computer programming course run by NIIT.

Mr. Singh and several other engineering graduates said they learned quickly that they needn't bother to go to some classes. "The faculty take it very casually, and the students take it very casually, like they've all agreed not to be bothered too much," Mr. Singh says. He says he routinely missed a couple of days of classes a week, and it took just three or four days of cramming from the textbook at the end of the semester to pass the exams.

Others said cheating, often in collaboration with test graders, is rampant. Deepak Sharma, 26, failed several exams when he was enrolled at a top engineering college outside of Delhi, until he finally figured out the trick: Writing his mobile number on the exam paper.

That's what he did for a theory-of-computation exam, and shortly after, he says the examiner called him and offered to pass him and his friends if they paid 10,000 rupees each, about $250. He and four friends pulled together the money, and they all passed the test.

"I feel almost 99% certain that if I didn't pay the money, I would have failed the exam again," says Mr. Sharma.

BC Nakra, Pro Vice Chancellor of ITM University, where Mr. Sharma studied, said in an interview that there is no cheating at his school, and that if anyone were spotted cheating in this way, he would be "behind bars." He said he had read about a case or two in the newspaper, and in the "rarest of the rare cases, it might happen somewhere, and if you blow [it] out of all proportions, it effects the entire community." The examiner couldn't be located for comment.

Cheating aside, the Indian education system needs to change its entire orientation to focus on learning, says Saurabh Govil, senior vice president in human resources at Wipro Technologies. Wipro, India's third largest software exporter by sales, says it has struggled to find skilled workers. The problem, says Mr. Govil, is immense: "How are you able to change the mind-set that knowledge is more than a stamp?"

Anonymous said...

The average graduate's "ability to comprehend and converse is very low," says Satya Sai Sylada, 24/7 Customer's head of hiring for India. "That's the biggest challenge we face."

Indeed, demand for skilled labor continues to grow. Tata Consultancy Services, part of the Tata Group, expects to hire 65,000 people this year, up from 38,000 last year and 700 in 1986.

Trying to bridge the widening chasm between job requirements and the skills of graduates, Tata has extended its internal training program. It puts fresh graduates through 72 days of training, double the duration in 1986, says Tata chief executive N. Chandrasekaran. Tata has a special campus in south India where it trains 9,000 recruits at a time, and has plans to bump that up to 10,000.

Wipro runs an even longer, 90-day training program to address what Mr. Govil, the human-resources executive, calls the "inherent inadequacies" in Indian engineering education. The company can train 5,000 employees at once.

Both companies sent teams of employees to India's approximately 3,000 engineering colleges to assess the quality of each before they decided where to focus their campus recruiting efforts. Tata says 300 of the schools made the cut; for Wipro, only 100 did.

Anonymous said...

"Concentrate attention for an extended period of time" seems to characterize Western modes of thought and behavior. Dialectic, step-by-step logical demonstration, what mathematicians call "Sitzfleisch", are major features of Western modes and involve extended concentration. The Chinese, by contrast, seem to have an aversion to these kinds of modes and identify thinking with sensing and intuition.

Anonymous said...

It seems to fall victim to a fundamental tenet of science: correlation is not causation.

Actually that's not a fundamental tenet of science. In fact the exact opposite is closer to being a fundamental tenet of science. "Causation is just correlation", "there is no causation, only correlation", etc., are all closer to being fundamental tenets of science.

"Causation" is a relic of Aristotelian metaphysics and probably of even older, pre-philosophical thought.

There is only direction of entropy as measured by gradients of correlation.

It is one of those dirty secrets of science.

Sean said...

I'll grant you the Chinese don't excel at abstract reasoning to the extent they do at observational attention on concrete things. Chinese are good at CSI because they do not miss much. Their verbal IQ is unimpressive though. The Ashkenazi Jews' high verbal IQ goes along with superior abstract reasoning. Piffer's results for Chinese may be explained by the genes he used being actually genes for thinking that is spatial and concrete rather than verbal and abstract thought.
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'"Causation is just correlation", "there is no causation, only correlation", etc., are all closer to being fundamental tenets of science."

That's not what Malebranche thought, and Hume pinched his idea that genuine causal connections didn't exist from Malebranche. Anyway, as Balfour showed, we can never know. Pretentious, moi?

Gottlieb said...

Majority of chineses and cia are like as ''superficial memorisers'' as public employeers in the West. They have features as above iq and low psychological intensity (predisposition to mental illness). Memorization without intelectual profundity or with very ''techcnical'' enphasizing. Learn to apply and earn Money. In the West, many whites also are like that, but in the West cause more psychopathology or psychopath personality than east asians, there more cognitive combinations that because unusually intelectual profiles, were are the creative genius. Genetic random result in the genius. Schizophrenia genes can cause cognitive deterioriation, specially in people with iq less than 80 but also can cause growing of brain activity, it related directly with better growing activity.
Chineses and cia eliminate the majority of this supposed ''bad genes'' specially because creative people tend to be inconformist.
''Mental illnesses'' genes are heterogeneous and can result in variable results, the best to the the worst.
Asians and cia have more healthy people and are more genetic homogeneous. Heterogeneous genes create inconformist cultures and homogeneous genes create conformist cultures by two mechanisms to conformist cultures, cousins marriage (phenotype) or racial purity(genotype).
I could talk that creativity is a way of progressive deterioriation of brain activity, because the brain is beeing used above its capacity. Creative genius would to be as ''people who use brain above its capacity and limits and this cause progressive deterioriation of cognitive capacity''.

Ben10 said...

About the ingress of Neanderthal fatty acid-related genes into moderns, check this in Dienekes blog:

http://dienekes.blogspot.com/
of April 2nd, 2014.

"...The team found that Europeans had differences in the concentration of various fatty acids in the brain that were not found in Asians or chimpanzees, which suggests they had evolved recently. The Europeans also showed differences in the function of enzymes that are known to be involved with the metabolism of fat in the brain.
Now the team is trying to figure out what the fatty acids do in the brain and how differences in their concentration might affect function. “We think it’s a very strong effect with very profound physiological changes,” Khaitovich says. “Otherwise, we wouldn’t see it in the brain tissue.” "

Sean said...

trooduasortGotlieb, there have long been claims for increased creativity in the families of schizophrenics. One thing is for certain; schizophrenia appears when sex hormons peak.

Ben10, the lead researchers behind a couple of studies that implicated 'Neanderthal' genes in human disease were interviewed on the BBC, and it was something like 2 Neanderthal linked out of 50 implicated in diabetes. These things tend to get get over-interpreted at first, like ASPM did.

Gottlieb said...

Big problem about psychometric tests to compare the West and East.

https://www.youtube.com/watch?v=ZoDtoB9Abck

This docummentary talk that ''westerners'' tend to be better to memorise when they are talking aloud. ''Easterners'' tend to be better to memmorise when they are talking for themselves or with a ''internal way to study''.
For determined kind of psychometric analyses when easterners and westerners are making the same test in a quiet classroom, to seems that easterners will have a 'environmental'' advantages because westerners are better to memorise when they are studying in aloud voice and in psychometric evaluations with groups or even only with a one person, supposedly is necessary to get silence to make a better test.

Gottlieb said...

Creativity (methaphorically talking) mechanisms is like as ''Malthusian theory''. When the demand surpass the capacity (limit). In a hypothetical population the ratio demography x food capacity is broken, equilibrim is broken.
Creative brain is the brain that work above its capacity, resulting in genetic deterioration, when you eat the food in three days that should last a week. Hungry brain.
Interesting, life ''out human body'' emulate ''inside human body''. When the food capacity is overcome by population numbers then happens a social and economic (premature) deterioration cause by broken of this equilibrium.