Tuesday, June 17, 2008

Asian-White IQ variance from PISA results

The vexing question of average differences between groups of humans has been the subject of scrutiny for a very long time. Differences in variance or standard deviation (SD) are less well understood, but have important implications as well. This point was emphasized during the Larry Summers debacle, in which he posited that the variance in male intelligence might be larger than for women, even though the averages are similar (more very dumb and very bright men than women). Summers argued that this effect might explain the preponderance of males in science and engineering, even for a very small difference in SD.

Summers NBER speech:
...If one supposes, as I think is reasonable, that if one is talking about physicists at a top twenty-five research university, one is not talking about people who are two standard deviations above the mean. And perhaps it's not even talking about somebody who is three standard deviations above the mean. But it's talking about people who are three and a half, four standard deviations above the mean in the one in 5,000, one in 10,000 class. Even small differences in the standard deviation will translate into very large differences in the available pool substantially out [on the tail].

I did a very crude calculation, which I'm sure was wrong and certainly was unsubtle, twenty different ways. I looked at the Xie and Shauman paper-looked at the book, rather-looked at the evidence on the sex ratios in the top 5% of twelfth graders. If you look at those-they're all over the map, depends on which test, whether it's math, or science, and so forth-but 50% women, one woman for every two men, would be a high-end estimate from their estimates. From that, you can back out a difference in the implied standard deviations that works out to be about 20%. And from that, you can work out the difference out several standard deviations. If you do that calculation-and I have no reason to think that it couldn't be refined in a hundred ways-you get five to one, at the high end.

I've occasionally heard a variant of the Summers argument applied to Europeans vs Asians (specifically, NE Asians such as Japanese, Koreans and Chinese): although NE Asians exhibit higher averages than whites in psychometric tests (SAT, IQ, etc.), some suspect a smaller variance, leading to fewer "geniuses" per capita, despite the higher mean. See, e.g., this article in National Review:

...The two populations also differ in the variability of their scores. A representative sample of Americans or Europeans will show more variability than will an East Asian sample. In the familiar bell-shaped distribution curve, the bell is much narrower for the Japanese--which is what you would expect from such a homogeneous population.

This difference is a major matter, and it is worth focusing hard on the data. Just about all Western populations report a standard deviation of 15 IQ points. (The SD, a basic measure of variability, quantifies the extent to which a series of figures deviates from its mean.) But the SD for the Japanese and other East Asian populations appears to be a shade under 13 IQ points. That difference does not sound like a big deal, and, in fact, it does not change things much in the center of the distribution. ...

...but it does make a big difference at the high end, and it affects estimates of elite human capital availability in different countries.

I've never seen any data to support the smaller NE Asian SD claim. Looking at SAT data shows a larger variance for the Asian-Pacific Islander category, but that is not surprising since it's a catch-all category that includes S. Asians, SE Asians, NE Asians and Pacific Islanders. I've found very little analysis specific to NE Asians, so I decided to produce some myself. I took the 2006 PISA (OECD Program for International Student Assessment) data, which is painstakingly assembled every 3 years by a huge team of psychologists and educators (400k students from 57 countries tested). The samples are supposed to be statistically representative of the various countries, and the tests are carefully translated into different languages. Most studies of national IQ are quite crude, and subject to numerous methodological uncertainties, although the overall results tend to correlate with PISA results.

Below is what I obtained from the 2006 PISA mathematics exam data (overall rankings by average score here). To get the data, scroll down this page and download the chapter 6 data in .xls spreadsheet format. Level 6 is the highest achievement category listed in the data. For most OECD countries, e.g., France, Germany, UK, only a few percent of students attained this level of performance. In NE Asian countries as many as 11% of students performed at this level. Using these percentages and the country averages, one can extract the SD. (Level 6 = raw score 669, or +1.88SD for OECD, +1.28SD for NE Asians.)

OECD AVG=500 SD=90

NE Asia (HK, Korea, Taiwan) AVG=548 SD=95

The NE Asians performed about .5 SD better on average (consistent with IQ test results), and exhibited similar (somewhat higher) variance. (After doing my calculations I realized that there is actually a table of means and SDs in the spreadsheet, that more or less agree with my results. The standard error for the given SDs is only 1-2 points, so I guess a gap of 5 or 10 points is statistically significant.)

Interestingly, the Finns performed quite well on the exam, posting a very high average, but their SD is smaller. The usual arguments about a (slightly) "narrow bell curve" might apply to the Finns, but apparently not to the NE Asians.

Finland AVG=548 SD=80

Returning to Summers' calculation, and boldly extrapolating the normal distribution to the far tail (not necessarily reliable, but let's follow Larry a bit further), the fraction of NE Asians at +4SD (relative to the OECD avg) is about 1 in 4k, whereas the fraction of Europeans at +4SD is 1 in 33k. So the relative representation is about 8 to 1. (This assumed the same SD=90 for both populations. The Finnish numbers might be similar, although it depends crucially on whether you use the smaller SD=80.) Are these results plausible? Have a look at the pictures here of the last dozen or so US Mathematical Olympiad teams (the US Asian population percentage is about 3 percent; the most recent team seems to be about half Asians). The IMO results from 2007 are here. Of the top 15 countries, half are East Asian (including tiny Hong Kong, which outperformed Germany, India and the UK).

Incidentally, again assuming a normal distribution, there are only about 10k people in the US who perform at +4SD (and a similar number in Europe), so this is quite a select population (roughly, the top few hundred high school seniors each year in the US). If you extrapolate the NE Asian numbers to the 1.3 billion population of China you get something like 300k individuals at this level, which is pretty overwhelming.

As for verbal abilities, we have the following 2006 PISA results: OECD reading avg is about 490; France 488, Germany 495, UK 495, Italy 469, Spain 461. NE Asian scores: Japan 498 Korea 556 HK 536 Taiwan 496. Again, slightly higher scores for NE Asians. Some interesting US data here shows that on 1995 SATs, low-income Asians have lower verbal scores than whites, but by family income of $60k have caught up and Asians with family income of >$70k outscore white families of similar affluence. This strikes me as an immigrant / bilingual family effect. Children raised in immigrant families, where the parents do not speak English at home, tend to score lower on the verbal part of the SAT.


Although it's all there in the data set, I didn't have time to examine the male-female variances in mathematical ability (and don't want to deal with the abuse that might be heaped on me based on what I might find), but I encourage any interested readers to have a look. The authors of the PISA report wisely only reported that male-female averages are similar ;-)

Note: as often happens with this kind of topic, a related discussion has broken out at GNXP.

46 comments:

David said...

Mostly for my curiosity, do you consider all of China as NE Asia?

steve said...

The genetic clustering analysis I have seen shows that Chinese from the north are very close to Koreans and Japanese, and from the south just a bit more distant. But the population has undergone a lot of mixing and migration in the last thousands of years so it is relatively homogeneous. From the psychometric perspective people from HK and Taiwan, who as a group are really closer to southerners, perform more or less the same as Koreans or Japanese or Chinese from the north. So I think this implies that more or less the entire 1.3 billion population of China will probably perform similarly once the standard of living and education levels improve. At the moment no more than 200-300M people there have access to (PPP-adjusted) middle class lifestyles.

Scott said...

I found the neighboring country-country differences interesting. I wouldn't know how to explain it. The percentage of Koreans at Level 6 is much higher than the percentage for the Japanese. Similarly, the percentage of Finns reaching Level 6 is much higher than for Swedes and Norwegians.

steve said...

PISA definitely shows some variation which can only be explained by differences in national educational system. Note I am not an extreme hereditarian -- a big chunk of variation in cognitive development comes from environment.

An IQ fanatic might complain that the PISA exams are not as highly g-loaded as, e.g., Ravens matrices, but on the other hand coaching can probably improve performance on that test as well.

My narrow goal was just to see if there was a reduced variance (SD) in the Asian data, and there does not seem to be. The main effect is a displaced avg, but SD is the same.

Anonymous said...

I found the post interesting, but am not posting a comment related to its content.... I'm sure you will be "happy" to know, all the google ads for this post ask me to click to meet single young Asian women.

steve said...

Sweet! Maybe it will generate some revenue for my blog. I think you should check it out... :-)

Juha said...

You might be interested to know that Finnish males are originally from NE Asia -- Northern China to be exact -- see Rootsi et al (2006), "A counter-clockwise northern route of the Y-chromosome haplogroup N from Southeast Asia towards Europe" (European Journal of Human Genetics, pp. 1-8).

steve said...

Wow!

http://www.isogg.org/tree/ISOGG_HapgrpN07.html

Y-DNA haplogroup N is found throughout Northern Eurasia. Possible points of origin include Northern China and Mongolia, from which the population spread both toward the Baltic region and into Siberia. The dominant N3 branch is found widely distributed in Siberia and in northern Europe. At its western extent, the greatest concentration is found among Finns, Latvians and Lithuanians. The N2 branch, whose geography is largely contained within the larger N3 range, shows two clusters, one in the Ural-Volga area and the other further east. The less common N1 lineage shows a scattered distribution in Asia, with small concentrations in areas of Kazakhstan, Korea and China. The undifferentiated N* population is widely distributed at low levels of occurrence with a weak concentration in Cambodia and southern China. Haplogroup N has also been found at very low concentration in eastern Europe and in Anatolia.

Rootsi et al. :

http://www.nature.com/ejhg/journal/v15/n2/abs/5201748a.html

Razib said...

You might be interested to know that Finnish males are originally from NE Asia

you're talking about y chromosomal lineages; only a very small proportion of ancestry. additionally, there have been controversies as to whether these haplotypes are actually from siberia, or whether the siberian ones are from the environs of finland.

Anonymous said...

you might be interested in this article by Gottfredson.

http://www.udel.edu/educ/gottfredson/reprints/2004desegregatingGiftedEducation.pdf

SHe is using the data from a study she did in 2003 using the Wechsler Scale for Children (WISC). Her results are that "Asian" American children have a mean IQ that is 106 as compared to white children at 101.4 and a standard deviation of 15 compared to 14.7 respectively. (go to page 8)

Now, I don't have her sample sizes so I don't know how to get the standard error to see if that small difference in favor of Asian kids' variance is very significant but I don't think it is.

I think it's better to stick with tests like the WISC and other traditional IQ tests because the differences on other tests might be due to different studying habits, etc, not intelligence. Unfortunately, there's not that much data out there on Asian Americans. In fact, I am not even sure that the mean IQ is higher for Asians. To be sure there needs to be more studies.

steve said...

I've actually seen that paper before, but I thought perhaps she simply assumed SD=15 to generate the Asian numbers. Is there any evidence she extracted that from data? Why is the white SD=14.7 but the Asian one exactly 15?

Anonymous said...

It seems to me the fundamental flaw in all this is that much of a person's PISA score is due to education and not aptitude. Regions with better mathematics education will have higher PISA scores, and nations with greater inequality in mathematics education will exhibit higher standard deviations; but neither of these effects would be due to biology. There is also the possibility that different native languages result in different 'aptitudes' for mathematics.

Reasons like these always cloud comparisons of cognitive abilities. Although I find this subject fascinating, more and more I think this kind of "clinical" approach offers more deception than illumination.

I'm reminded of the silly health/medical meta-studies one finds headlining Yahoo tickers and the like: "Study shows X regular behavior might cause Y negative consequence." We don't trust these because they come from blind data mining, searching for correlations without having any reason to expect them, and being reckless with systematic uncertainties. Well, I think one should apply the same skepticism to comparisons of cognitive abilities. Come up with a biological reason why one race might have greater mean or stddev in aptitudes, and then it might be worthwhile to see if the 'thoeretical prediction' appears in data.

An example that occurred to me some time ago is, maybe men have larger stddev than women because something related to brain structure/function appears on the X chromosome. Women having two Xs could tend to 'drag' them to average, while male attributes would be more volatile. I would guess this idea is wrong, but at least it's a reason, and as such it gives directions for research that are independent of comparing SAT scores etc.

steve said...

In this analysis I am not primarily interested in biological causes. If you want to estimate the depth of human capital in a particular country/region, you don't need to know what *caused* the distribution. You simply want to know what the pool of (in this case) 15 year olds is like in that country, because that has consequences for the future. You might expect Taiwan to produce more good engineers than, say, France if the relative percentages of Level 6 PISA scorers is 12% vs 2%.

To return to your medical example, I might not know *why* cancer rates are higher in region 1 than region 2, but knowing the rates themselves is still valuable information.

If you want to get at biological causes (heredity), there are many twins studies, adoption studies, etc. that are consistent with the PISA results. The PISA variations can be interpreted as saying that quality of schools has an impact on outcomes, but doesn't in any way contradict a heritability of, e.g., .5-.7 that is obtained from the other studies. Have a look at the GNXP thread I linked to at the end of the post.

Anonymous said...

Anonymous said "... nations with greater inequality in mathematics education will exhibit higher standard deviations ..."

This is a perfectly reasonable statement. I just want to point out that random inequality in education is expected to reduce the average as well as increase the SD. So inequality alone can not explain higher mean and higher SD.

The assumption here is that it's easier to reduce an individual's math score by poor education than it's to increase the score much beyond what an adequate education will give him.

However, carefully managed inequality can potentially maintain the mean while increase the SD. This requires giving better education to kids with more capacity for learning, and let the rest get by with less educational resources.

Anonymous said...

steve,

I'm the one who posted that Gottfredson link. The number 15 for the standard deviation given for the WISC is standarized for American children, not white children. Since many minorities' mean scores are markedly lower than whites (whites make up about 68% of the US population), there tends to be a bimodal distribution. That bimodality stretches out the curve (i.e., more platykurtic). So 14.7 for the white sd is not hard to imagine.

JuJuby

steve said...

That wasn't exactly my point. She took the time to extract a rather exact value of 14.7 for the W SD, but used a round figure of 15 for the A SD. It seems that she just assumed the A SD was 15. If she extracted it from data it would be unlikely to be exactly 15 (why not 15.1 or 14.9?).

Do you have a reference where she actually talks about the A WISC data set, and extracts an SD with an associated SE (standard error)?

Anonymous said...

steve,

she only cites "based on data in Gottfredson 2003b". So no, I don't have the data. I'm suspicious of it because of that fact. I don't know how many Asians where included in her data set.

JuJuby

steve said...

I believe she extracted the quoted mean of 106 for Asians and 91 for Hispanics, but just arbitrarily assumed an SD=15 for both groups, since 15 is the "standard" value. It's only in recent refinements of IQ studies that the variance has become an issue of interest. In the old days the main issue was the mean. (It's still a big issue, if you know what I mean.)

steve said...

I would have liked to have seen a result from Gottfredson because it would have saved me the time of looking at the PISA data :-)

Anonymous said...

The reason why I don't think that's the case is because she uses specific figures for the other groups and the point of her paper was to analyse the porportion of children in each data set in the gifted range (according to her, equal to or greater than 2 sd above the overall mean). So the SD for each group would be essential to that calculation.

steve said...

Yes, but if one assumes all the SDs are close to 15 (not a bad assumption, it turns out), then it is the difference in means that gives the main effect for the central part of the distribution. I agree, it's sloppy, but ultimately her curves/table are probably fairly correct because she doesn't go anywhere near the far tail, e.g., +4SD.

Mr. Gunn said...

What I'd really love to see, based on Razib's suggestion that intelligence is necessary but not sufficient for scientific creativity, is data like testosterone level, body weight, socioeconomic status, and so on matched with the IQ score.

Anonymous said...

This is a great post. I'd point out that IQ correlates highly with PISA and TIMSS results:

http://groups.uni-paderborn.de/rindermann/materialien/PublikationsPDFs/07EJP

and in Lubinski's gifted study you'll note that

http://www.appstate.edu/~webbrm/jap2001.pdf

"All 320 participants (78% Caucasian, 20% Asian, 2% other) in this
10-year follow-up study secured scores that were either S700 in the math
portion of the SAT (SAT-M) or &630 in the verbal portion of the SAT
(SAT-V) before age 13 (1980-1983)."

consists of 20% Asian. If the variance of Asians is lower, that would imply impossibly high Asian means at this far right of the bell curve.

Anonymous said...

There are lies, damn lies and statistics.

ENOUGH said of this crap.

The man with highest present recorded IQ at over 200 is frustrated bouncer-scientist-wanna-be who suffered mental and physical abuse from his step father.

IQ means nothing if not less than nothing...

So, STOP discussing IQ differences between the races, because all you engender by this kind of talk is an inferior and a superior group feeling. And we all know what that can lead to...

Qi said...

Hi, Steve, I have enjoyed reading your blog for awhile now, just wondering, have you considered that racial divisions in a country is dictated for the purposes of its political factions?

Rather than testing between Taiwanese and German-Americans, why not test between the Hmongs and the Finns, or the between the Burmese and the Gujarats, or the Hui Chinese with Hasidic Jews? According to Wikipedia, the group in the US with highest education level is Nigerian Americans.

Independent of environmental effects, it seems difficult to prove any Asian-white or Asian-black IQ gap is existent; the sample used in the current analysis seems impossibly biased.

steve said...

Anonymous: if you think IQ means nothing, please have a look at the more recent post on measured IQs of eminent science and the ensuing discussion:

http://infoproc.blogspot.com/2008/07/annals-of-psychometry-iqs-of-eminent.html

Qi: I don't know what you are trying to say. If you think there is a problem with, e.g., the methodology of PISA or IQ testing or the meaning of the results, please say so. Note this discussion is not focused on heritability or environmental causes, just on the actual psychometric results themselves.

Qi said...

>>If you extrapolate the NE Asian >>numbers to the 1.3 billion >>population of China you get >>something like 300k individuals at >>this level, which is pretty >>overwhelming.

According to this website,
http://www.asian-nation.org/immigrant-stats.shtml
immigrants in the US from Africa have a rate of 52% of college degree or higher. Let's assume one needs to have an IQ one SD plus mean to have been educated in an American college. Can we conclude that 52% of 113 million Nigerians have an IQ at least one SD above the mean?

With all due respect Steve, I just feel that it is difficult to draw objective and useful conclusions from population IQ studies.

I don't deny the validity of IQ test results, it captures logical sharpness and processing speed, but it overlook qualitative talents such as in art, literature, and other "reflective" intellectual fields. How would have Goethe or Su Shi score on their IQ tests?

steve said...

Qi:

Who says the African immigrants here are representative of their national populations? Extrapolating the 52% figure to the entire population of Africa is a stretch. (Also, are those degrees obtained in the US or in Africa? It may affect your +1 SD estimate.)

I'm sure you understand what a selection effect is. The designers of tests like PISA try to obtain nationally representative samples. That's why the results are more meaningful than some random statistic like yours. Are you saying that PISA exams are not indicative (broadly speaking) of national educational achievement? Note, I didn't make any comments about scores of African countries, mainly because I haven't seen data of similar quality to PISA, TIMMS, etc.

Re: Goethe, see below for an estimate and note the difference between ratio and deviation IQs. Who knows whether Cox's estimates are accurate, but it's safe to guess that Goethe would have had a very high score on an IQ test.

http://www.iqcomparisonsite.com/Cox300.aspx

Re: the China quote and 300k at +4SD, I think I qualified that in the original post: it depends on extrapolation of the normal distribution into the tail, etc.

Justin said...

I believe that the East Asians are far more intelligent than whites. I also do not find evidence compelling for greater variance in white intelligence. What I find compelling is the disparity in Formula 1 racing in which I worked many years. F1 provides a real world Japan vs. West showdown. The results are evident, when inventiveness and innovation are required, the British and Italians are masters. When stability is at play, the Japanese rule. I have yet to see this paradigm falter. Very fascinating.

Qönttä said...

PISA tests heavily the reading comprehension skills. It is questionable how much it tests the math skills.

A statistician could dig the data and find out the factors below the surface of the results.

Countries with a small number of immigrants who do not comprehend the questions in PISA test seem to do fine, like Finland and Chinese speaking countries.

And now the juicy racism bit.

Finns are about 30% German and the nearest racial relatives are Estonians who do not seem to perform spectacularly. Are there too many Russians in the sample or is it cultural.

But wait, isn't it Russians who are cathing nowadays those Nobel prizes from Jews? And Israel didn't perform very well in the test either. And nearby Russians are 30% genetically Finns.

Nobel Prize has been granted twice to Finland. Linux, IRC and Nokia came from Finland. The participation in Mensa is one of the highest in the world. Additionally there are 30% more cases of schizofrenia than in other countries. Schizofrenia is linked to good observational skills and IQ less than 120. Thus, I doubt that SD in Finland is less than average.

The PISA test is taken by kids at age of 15. The IQ tests taken by adults in Finland have shown slightly lower scores than in other European countries: http://en.wikipedia.org/wiki/List_of_countries_by_IQ (Another statics from 1980's gave a rather bad placement for Finland)

What comes to the universities, Finland is on rank 14
http://ed.sjtu.edu.cn/rank/2007/ARWU2007Statistics.htm but similar size countries like Sweden, Norway, Denmark and Israel are leading.

But definitely there is something going on which PISA test captures.

Finnish schools teach much languages and the PISA test questions look like reading comprehension quizzes of English, Swedish and German.

lgy said...
This comment has been removed by the author.
lgy said...

This is my search in 2006 through the Home network literature database to collect some of the Chinese primary school children in areas of data:
Note: on the network has multiple versions, this is my first published in post.baidu.com

From the table that China can be between children with IQ (non-adult) differences are great, and the main difference is not a North-South differences, but something different, at least from the surface, children's IQ with the regional economic development A great level of relations

2005 National Health Survey of iodine deficiency was the average IQ of children around the data

Before they know the children's IQ over 110 are Beijing, Shanghai and Zhejiang provinces.
Yesterday, a careful search the Ministry of Health on the country in 2005 caused by iodine deficiency tracking survey.
Zhejiang found that the average IQ of children as high as 115.05, less than the Shanghai data search
Search engine: google Scholar
A standard IQ test: No. 2 modified version Ruiwen
Test of time: the first half of 2005


Zhejiang rural boy 116.23
Zhejiang average boy 115.82
Zhejiang men and women an average of 115.05
Beijing rural 114.9
Hangzhou City 114.7
Zhejiang rural girls 114.41
Zhejiang girls an average of 114.32
Wenzhou (5 counties average) 114.195
Beijing average 114.07
Zhejiang city girl 113.73
Zhejiang city boy, 113.46
Beijing city an average of 112.6
The national average 103.5

Hubei 111 urban children (prefecture-level cities and provincial towns)
Jilin average 107.04
Jiangsu average 109
Hubei county-level city and county 106.4
Hubei average boy 105.44
Hubei average 105.3
Sichuan 105.3
Hubei girls 105.1
Guangdong 103.4 or 101.1
Hebei towns 98.04 in 2004
National 2002 97.5

The results of this investigation in order to prevent malicious tampering, Below is my digital signature (md5)
nick: 7b908987bbb5b99c8b60d325212ea67e
text: 3729f8f0bb7b7a64db4967fde89b7561
email: df47121fbacaa60e4de2a8fb5a927f08

Oyomei said...

Steve,

I am not so much challenging what you are saying but simply stating that I am very skeptical of any innate advantages of one ethnic group over another. African immigrants are certainly not representative of their native populations, but neither are Chinese immigrants. I have not seen a complete collection of regional data of Chinese provinces, but I am certain that the averages in the affluent coastal provinces (where Chinese immigrants are mostly from) are higher than inland ones.

In regards to athletic performance, for instance, yes the top sprinters are almost exclusively of West African descent, but almost never actually from a West African country. They are usually from North America or the Caribbean where there is high likelihood that they are mixed with Europeans or American Indians. In terms of per capita represented in the NFL, it is Samoans and Tongans (who are genetically related to Southeast Asians) that are completely dominant, particularly in positions that demand power and explosiveness.

Regards,
Qi

Anonymous said...

I'm curious as to what Shandong's score is, because they are supposedly the smartest and highest scoring province in China (Zhejiang is second).

CK said...

I suspect data from countries with large immigrant populations should be treated with much suspicion. From my observations, the children of immigrants tend to almost always work harder than their native peers.

Cultural differences also need to be considered strongly. In my own upbringing I met with east asians, caucasians, and polynesians. Culturally the east asians prized academic achievement highest, the caucasians prized some form of 'balance' i.e. academia and sport/cultural activities and the polynesians esteemed the sports and athletic achievements most highly. The physiques of my peers certainly represented their respective cultural biases - it is not surprising to me that their intellects and academic results followed suit.

The importance of this observation I guess is to point out that these differences (although they do exist), should be taken with a grain of salt in terms of any implications. It seems to me that they merely confirm that people who study hard and prize knowledge wind up with more capable intellects, which is of course, not surprising.

Kevin Stewart said...

Steve, are these studies accounting for the racial diversity that exists within Western Europe and America? NE Asia is relatively homogeneous so a sampling of this population is obviously going to reveal the true IQ of this group. Western Europe, on the otherhand, has become, in the last 20-30 years or so, inundated with minorities from undeveloped countries who traditionally score low on IQ tests, and thus may lower the average score of these representative countries. To truly be fair in testing cognitive differences in racial groups, one would have to account for the minorities being tested in these countries.

Also another concern of mine is the concept of 'whiteness' is changing in America, as racial mixing is becoming more prevalent. Those who are marking themselves as white/caucasian on census forms and other applications are becoming increasingly less white each generation (e.g. in 1850 those who considered themselves white were almost exclusively 100% white but present day whites because of historical miscegenation may only be on average 90%-95% 'white'). Since historically whites have mixed with natives and blacks and both these groups have inferior IQs to whites it would be interesting to test if whites that contain DNA from these two groups score lower on IQ tests. Thus, whites with admixture from these two other racial groups may dampen the average IQ score of whites in general.

Baron Baal said...

Steve, this rhetoric is useless. You E.Asians have your big brains and the whites have theirs, and even if China could come up with 200 million quality engineers and scientists, who's going to employ them? This world we live in is controlled by the super smart and the super rich, and as of now whites have a bit more of both when compared to the E. Asians. So yes, Steve, if you want to go around feeling good about yourself because E.Asians are smarter than whites then go ahead but in the real world it really doesn't matter.

Baron Baal said...

Steve, this rhetoric is useless. The E.Asians have their big brains and the whites have theirs, and that's what's important. And even if a country like China could produce 200 million quality engineers, who's going to employ them? The super smart and the super rich control this world, and as of now there are more whites in this group than E.Asians. If you want to go around feeling good about yourself because E.Asians are smarter than whites then go ahead, but in the end it really doesn't matter.

Space Kozak said...

>Come up with a biological reason why one race might have greater mean or
stddev in aptitudes, and then it might be worthwhile to see if the
'thoeretical prediction' appears in data.

I realize I'm replying to a three year old post, but wouldn't the differences in brain-sizes (that are present even at birth) alone be a biological reason enough to expect differences in cognitive ability? Using MRI the correlation between brain size and IQ is .40 (up to .65 in some studies that also adjusted for body size). The 'theoretical prediction' does appear in the data (although White and East-Asian brains appear more 'efficient' as well, as "they found a correlation of –.58 between glucose metabolic rate and IQ").

I would assume you have already read Rushton and Jensen's meta-analysis "Thirty Years of Research on Race Differences in Cognitive Ability" (from 2005) and "Section 6: Race, Brain Size, and Cognitive Ability" (p 253/19) covers the differences in brain sizes. Here's an excerpt:
"Rushton (2000; Rushton & Ankney, 1996) summarized the world database using the three methods on which there are a sufficient number of studies (autopsies, endocranial volume, and head measurements), as well as head measurements corrected for body size (see Rushton, 2000, pp. 126–132, Table 6.6). The results in cm3 or equivalents were as follows: East Asians = 1,351, 1,415, 1,335, and 1,356 (M = 1,364); Whites = 1,356, 1,362, 1,341, and 1,329 (M = 1,347); and Blacks = 1,223, 1,268, 1,284, and 1,294 (M = 1,267). The overall mean for East Asians is 17 cm3 more than that for Whites and 97 cm3 more than that for Blacks. Within-race differences due to differences in method of estimation averaged 31 cm3. Because 1 cubic inch of brain matter contains millions of brain cells and hundreds of millions of synapses or neural connections, these group differences in average brain size may explain group differences in average IQ."
Another excerpt where it's been measures using MRI:
"For example, using MRI technology, Harvey, Persaud, Ron, Baker, and Murray (1994) found that 41 Blacks in Britain averaged a smaller brain volume than did 67 British Whites."
http://psychology.uwo.ca/faculty/rushtonpdfs/pppl1.pdf

Sadly, not a lot of testing using MRI has been done to assess race differences, but it matches the massive data from autopsies, endocranial volume and head measurements. As I said, brain-size differences are observable already at birth, appear to be highly genetic (heritability of 50-90%) and Black children start crawling, sitting, walking, etc. the fastest and East-Asians the slowest. There are also a host of other biological differences. So, in conlusion, I'd say there's plenty of biological reasons to expect race differences in cognitive abilities.

Space Kozak said...

Look, I wouldn't trust the math results too blindly. With a sane educational system one might, but I'm Swedish and at the age of 15 I was held back in school (because I was well ahead of the rest of my class). In fact, I didn't attend a single math lesson/class at all for the entire school-year when I was 15. (I'm not kidding.) I was not even offered to attend the math classes of the senior students, but was told to wait for the other students of my age... It was pretty much the same in elementary school as well.

Todd Smith said...

Interesting. I don't think IQ is a very good measure of what it means to be "smart". Steve jobs probably had an iq under 150 as measured by a pen and paper test, but his thinking had a much greater impact than most people with an "IQ" "higher" than his. Humans do so much, I think the very idea of measuring intelligence with a sit down test is absurd.

I define intelligence as a gift that for the most part CANT be learned. I dont think you could ever learn the subtle skills and thought processes that made Jobs one of the most dominate and powerful business men of all times- AND I ALSO DONT THINK YOU COULD TEST THAT LIKE YOU CAN MATH OR VERBAL SKILLS.

An Kevin the average IQ of "German adults form Germany" is 107 according to Dr. Richard Lynn- the worlds foremost "expert" on "IQ". Below is a press relase of his results.

http://www.dailymail.co.uk/news/article-381057/European-IQ-map-proves-Brits-brainy.html

Anonymous said...

So how does your analysis correspond to the PISA results of Russians, the number of Russian Nobel Prize winners in physics and the Asian ones? If you started thinking you would see that PISA test results have changed dramatically for many nations in the last decades while the genetic composition of the investigated populations did not. Correct the number of Russian Nobel Prize winners in Physics for the population size, than compare to Chineese ones. Once you draw conclusions on the Russian intelectual superiority over Chineese try to ask yourself a question how many of the Russians were of Jewish descendence. I will reval you a secret, the more you focus on single factor's effect on a complex issue the bigger missinterpretation will be. Posting it on internet will allow entire world to see imperfections of your logical thinking. Ego is a monster :)

X12 said...

Todd Smith said:
the average IQ of "German adults form Germany" is 107 according to Dr. Richard Lynn- the worlds foremost "expert" on "IQ".

In none of Richard Lynn's 3 books on national IQ data does he claim that Germany has a score of 107. For some reason the Flynn-adjusted results of Buj's 1981 study on assorted nation's average IQ has been misreported as Richard Lynn's national IQ estimates in the press, when these were just one study of a number that he used to determine national IQ scores. In his latest estimates from Intelligence: A Unifying Construct for the Social Sciences, he gives Germany an average of 98.8.

Caba Aba Baba said...

Interesting analysis. The data still shows that the top end of the Asian distribution compresses toward the top. For example, male Finns are 111 points behind China at the 75th percentile, but 91 behind at the 90th.

Harry said...

Your first claim is totally false. I suppose that the following is not really common knowledge amongst Americans or western Europeans for that matter: there is tremendous and stunning diversity within China and Asia. With 4 million people, Asia has over half of the world's population and there is no evidence to suggest that it is any less genetically diverse than other areas. On the part of China, which has more than 50 different ethnic groups, all these PISA tests and other cognitive tests administered to Han Chinese students are also administered to all the other non-Han Chinese ethnic students. It is an unfortunate fact due to both ignorance (though a natural one and I am not blaming anybody for anything, as you have not lived in Asia and so would not have had as much reason to know facts about Asia) and the desire to have research results or analyses show a certain conclusion that is causing you to make your specific claims. The claim that "NE Asia is relatively homogeneous" is one that would be uttered mostly by people with lesser familiarity with Asia or Northeast Asia; the more distant the people the less we tend to know about them and the more we tend to label them as homogeneous, or all part of the single, same mass. China's maintained unity over large temporal and spatial scales is not any evidence of lesser heterogeneity within its genetic pool.

Moreover, the "homogeneity" in several western European countries is still very high. Even France, well-known to be one of the most mixed nations in Europe, lists that 90% of people in metropolitan France are French (2010 census). The final thing I will note here is that a 10% "injection" of different ethnic populations that "traditionally score low on IQ tests" will have a near-marginal statistical effect on overall French IQ. Statistically speaking, if you had a population that was completely composed of "pure French" that have a mean IQ of 98, and then you injected different ethnic populations that have a mean IQ of say 85 (which is obviously exaggerated; I can't imagine that Eastern Europeans, or other Europeans, or North Africans, or Vietnamese who migrate to France have IQs of 85. I think better approximations would center around 95), then the new population would have a mean IQ of 96.82 ~ 97, a simple fact of statistics. The difference is 1 point even with the downwardly exaggerated immigrant mean IQ claim.

Regarding the second concern of the labeling of biracial or multiracial offspring, I'm sure others have more things to say, but first and foremost to my knowledge children of black and white couples have been labeled as black, not white, in America.

Harry said...

This entire post sweeps under the rug or does not account for the entire intention and design of cognitive tests—namely to be as free of environmental variables as possible, and to only test inherent variables. Moreover, these tests have been administered to children as young as three or four years old from different groups, with similar distributions being yielded as a result.

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