I recently looked at wave 5 (age 11) of the U.K. Millennium Cohort Study. You can read James Thompson's discussion of the wave 3 (age 5) results, published by Richard Lynn here. Based on my cursory analysis and consistent with GCSE results (and, more or less, the MCS wave 4 results) there was no Black-White gap (in verbal similarities).

I find this hard to square with a non-trivial hereditarian hypothesis. Any ideas?

Presumably at some point, some high-ranking anti-hereditarian is going to pick up this data point, and then lots of more competent people will look at it. I have been waiting for that to happen. So far no luck apparently.

Do you know anyone who can read Dutch? It would be nice to find more recent CITO scores, so to see if the gaps persist in Holland.

Google Translate can. :)Otherwise, ask Nijenhuis. He is Dutch.

It's increasingly difficult for me to take seriously a significant genotypic race-IQ hypothesis, let alone hereditarians, who can't be bothered to thoroughly look into this stuff. Cross generational spatial transferability is a basic prediction. And yet the evidence for this is rather inconsistent. This situation, in turn, makes it difficult for me to take seriously much of the related IQ research. If tens of thousands of years of separation haven't resulted in large spatial genotypic IQ differences, it's difficult to believe that similar such differences emerged in a much shorter time span.

I don't know -- but I'm downgrading the priority of this overall research project quite a bit.

I agree with Emil. I think this dataset is anomalous, pure and simple. The evidence for genotypic IQ differences between human races is overwhelming, about as well established as any conclusion in our field.

I believe Chuck is making a big fuss, more than this subject deserves. Just saying the BW gap is small in the UK without an interpretable environmental explanation cannot be accepted as an argument for environmental hypothesis. At the same time, Chuck failed to find any plausible explanation of the trend (if my memory is correct). So he is still asking a question worth answering.

Of course, it's just the verbal skill we are talking about, and I'm disappointed. Is there no figures for full IQ in that survey data ? I couldn't find anything else from the files he shared with me. (if someone wants it, email Chuck or me; we have the files, merged and collapsed, because they were initially a big mess.)

One possibility to disentangle this question, is to look at other european countries. I can easily believe that more egalitarian countries such as Scandinavian countries can be more effective at closing the racial gaps. What we need to know is the black-white IQ gap in these countries. It is known by many economists that the UK and the US share some resemblances, compared to the Scandinavian countries. Suppose you find racial gaps of about same magnitude here, then the small racial gaps become at odds with this pattern.

If hereditarians really had to focus on every dataset with odd results, they should still be spending time on the http://en.wikipedia.org/wiki/Eyferth_study, don't you think? After all, it seems pretty damn solid evidence against HH.

I have noted elsewhere this is the wrong interpretation of that study.

That study shows nearly no difference between the BW and WW children. Biracial scored equally well with white adoptees. When looking at the gender groups, something unexpected happens (Jensen, 1998, p. 482). There was an extremely large male-female gap in the white group. The white girls had a 8-points deficit with regard to the white boys. No such difference was found in the biracial groups. But generally, there is no difference in IQ between males and females in childhood (Rushton & Jensen, 2010, pp. 24-25), thus calling into question the Eyferth sample (Mackenzie, 1984, p. 1229). In adulthood, there might be an advantage for the males, but it is not clear whether or not this advantage is g-loaded (Jensen, 1998, pp. 536-540; Flores-Mendoza et al., 2013, Table 1). In reality, the BW-WW difference is null only because the white girls scored extremely low; when comparing the boys however, the BW-WW difference is consistent with the hereditarian hypothesis (HH).

I remember Chuck noted the same oddity in his blog "abc102.wordpress".

Then there's the entire failed history of trying to raise g thru compensatory education. Pretty much a big failure. It works for children, maybe (negative g-loading, cf. Nijenhuis et al, 2014). It fizzles out.

The argument is not necessarily correct. One can still argue that these studies are conducted in the US, and in the UK, the environment is different. In what way, I don't know, but if they want to argue this, they have to prove it. So far, it should be safer not to generalize studies in country A to country B, even though I believe they can be generalized to other european countries. The US seems to differ only in inequality (and perhaps mobility) compared to the european countries, partly because they are less egalitarians.

MH: This is handwaving move. Not argumentation. Remember we are talking about the Millennium data. For what I have read, that data is no joke. You can't dismiss it like this.

This is the best recent data point there is. The sample is not perfect but it is much better than those typically cited by Lynn. Speaking of which, in context to the Wave 3 results, Lynn and Cheng said:

"Second, the three groups of Africans obtained lower IQs than the whites with IQs of 96.68 (Black Caribbeans), 90.02 (Black Africans) and 91.95 (Other Blacks). These IQs are higher than those in the 22 previous studies summarised by Lynn (2006) in which Africans obtained a median IQ of 86. These results suggest that the intelligence of Africans has increased relative to that of whites in recent years. However, this apparent improvement may be in part attributable to the young age at which the children were tested."

And they were wrong. Instead of increasing with age the U.K B/W gaps decrease in line with a genetic difference hypothesis of 0.

I believe Chuck is making a big fuss, more than this subject deserves. Just saying the BW gap is small in the UK without an interpretable environmental explanation cannot be accepted as an argument for environmental hypothesis. At the same time, Chuck failed to find any plausible explanation of the trend (if my memory is correct). So he is still asking a question worth answering.

It's not just that it's small, it's that there was a marked secular evaporation at least when we place birth cohort on our x axis and trust Lynn's data.

As for the survey, technical information can be found [url=file:///C:/Users/John/Downloads/MCS%20Guide%20to%20the%20Datasets%20022014.pdf]here[/url]. Two other cognitive related tests were given: CANTAB Spatial Working Memory (Memory task) and CANTAB Cambridge Gambling Task (Decision making task). But I have no idea about the psychometric properties of these or how to compute standard scores for them (which aren't give). We do know, however, that similarities are a fair measure of g and that there is a moderate to large US B/W gap in these.

Regarding MH's claim that I need an explanation, I do not believe that I do. A hereditarian hypothesis predicts differences. Lynn rightly pointed out:

The evolutionary theory does however predict that when different races occupy approximately similar environments, such as for instance in the United States, Britain and the Netherlands, the intelligence differences will remain. This prediction has been examined in twenty three societies worldwide in Lynn (2008) and has been confirmed in every case. If a multiracial society is found where these race differences in intelligence are absent, the evolutionary and genetic theory of these differences would be falsified. Those who maintain that there are no genetic differences in intelligence between the races are urged to attempt this task. (Consistency of race differences in intelligence over millennia: A comment on Wicherts, Borsboom and Dolan)

The fact that White and Black youth in the UK now show diminishing differences argues against a hereditarian hypothesis. Pointing out the consistent differences in the US -- which of course I am well aware of because I've conduced the most recent meta-analyses on these! --doesn't negate this, since these differences are in the US and can plausibly be explained by societal factors.

Generally, I would suggest that the US difference is more resilient because there are more Blacks; thus it's more difficult to lift them up. In the UK the black population if smaller at 3% and thus more amendable to environmental intervention.

Then there's the entire failed history of trying to raise g thru compensatory education. Pretty much a big failure. It works for children, maybe (negative g-loading, cf. Nijenhuis et al, 2014). It fizzles out.

Has it ever been shown that the UK B/W gaps are g-loaded? If it has, we now have a good counter-example.

Look, it's not as if this is an isolated finding from the U.K. I pointed to math and reading and GCSE results two years ago. It was argued then that the math and reading scores, ones which were found to be under substantial genetic influence in the whole population, didn't well index IQ, so I said that I would look for youth IQ data, which I did. And here it is. Of course, I also looked at PISA scores for Black African British immigrants (e.g., attached) and I found similar non-results if based on tiny same sizes (but of course Lynn has cited samples as low as n=9!).

I will take as counter evidence Dutch Cito Scores from 2012 on, since we are basically dealing with similar populations e.g., Dutch Antilleans/ Black British Caribbeans. I can't make heads or tails of the recent Jaarrapporten, which should report these. In absence of evidence of a significant Holland gap I will attribute the high U.S. Black immigrant/White gaps to 10th generation U.S. Black undertow and declare the HH disconfirmed. If it can be shown that there are still large Holland gaps, I will rethink my position above -- and entertain the possibility of a UK psychometric conspiracy to cover up gaps.

Anyone who isn't troubled by the totality of the UK evidence regarding the B/W gap isn't being intellectually honest.
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I believe Chuck is making a big fuss, more than this subject deserves. Just saying the BW gap is small in the UK without an interpretable environmental explanation cannot be accepted as an argument for environmental hypothesis. At the same time, Chuck failed to find any plausible explanation of the trend (if my memory is correct). So he is still asking a question worth answering.

I. My explanation is: The UK is a totalitarian PC country that has devoted great energy to eliminating race differentials. And they have, over time, with use of positive discrimination. The hypothesis predicts:The B/W cognitive ability gap has been narrowing across age cohorts. It existed prior and it can be found among adults, testifying that Black immigrants weren't just super duper selected. (This hypothesis predicts, for example, that NART/PIAAC d-values -- from the samples I showed you -- should positively correlate with age.)

When I analyzed the PISA immigrant dataset, one of the first things I noticed was the low difference in scores between immigrants and natives in the UK, which is much smaller than that found in pretty much all the other Western countries. To me this is likely due to selective migration and has only one explanation: the geographical position of Britain and its geological status of an island. Think about it, Britain is an island far north in the Atlantic which admits immigrants only by airplane. People who can afford to fly are in general wealthier and better educated. In continental Europe we get immigrants from clandestine land routes (e.g. West Asia-Turkey-Germany) or even worse, on tiny boats manned by bandits that daily land in Sicily when they're lucky enough not to drown. When I'll hear of a rubber boat full of immigrants coming straigth from Morocco landing in Dover, then I'll reconsider my position. But until immigrants land in Britain at Heathrow like normal human beings, I will attribute these differences to the above explanation.

... immigrants

Isn't such name calling going to reflect poorly on this journal? I find the description puzzling at best...

... immigrants

Isn't such name calling going to reflect poorly on this journal? I find the description puzzling at best...

This is a forum thread other than official papers' review, not a journal. But I see your point, I toned it down a little. But I cannot hide the truth that immigrants that land in Italy are in a different state from those who arrive in the UK. It'd be a huge hypocrisy to deny it, and it would damage first of all the immigrants. People are already not enough aware of what is happening and the humanitarian catastrophe that happens daily along the southern coasts of Europe. Shall we pretend they land off their rubber boats dressed in expensive suits?

Shall we pretend they land off their rubber boats dressed in expensive suits?

I'm narrowly focusing on the Negroid (Black) - European Caucasoid (White) gaps. If there aren't such, I don't expect to find European/North African Caucasoid ones. Jamaicans, in fact, did come to the U.K. in the '50s and '60s by boat. And they had lower average measured IQs to start. But now, by the third-fourth generation the large difference among the youth has greatly narrowed to vanished. This can't be explained simply in terms of genetic assimilation and selective immigration.
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Anyway, I can read Dutch somewhat because it is close to German and Danish. Google Translate can make it semi-readable to people who speak English. Can you link to the report?

Obviously, if I had the report I could read it with a translator. But I need help finding one containing more recent Cito scores. The 2011 appendix, which contained CITO scores from '94 to '08, was called: Bijlagen Jaarrapport integratie 2011. The d-values declined significantly over the period (Turks (39%), Moroccans (45%), West Indians (39%), and Surinamese (16%). So I would like to see the d-value as of 2011/2012. If the Dutch West Indies gaps are also low < 0.5 SD and trending lower, this will be more evidence in favor of an environmental position. We will have another case of well documented differences (Lynn, 2008; Nijenhuis, 2004) -- indeed documented g-loaded ones! -- that diminished greatly.

I think it is dangerous and very misguided to draw conclusions only based on data but not on theory. In social science, doing this will cost you a lot. Environmental hypotheses predict lower gaps in countries with better environment, in particular, more egalitarian countries, those countries where the poors have higher social mobility and opportunity. The fact that HH prediction of meaningful differences everywhere is falsified does not make environmental hypothesis true or truer. All is needed is to show that in the UK, the environment is no better than in the US. This is sufficient to refute environmental hypotheses, regardless of the size of the gap. If you're merely saying that the gap is 0.5 SD in the UK, you're fine. But if you're trying to give a win for either of these competing hypotheses while in fact none of them fit the data, you're really in trouble.

I think it is dangerous and very misguided to draw conclusions only based on data but not on theory. In social science, doing this will cost you a lot. Environmental hypotheses predict lower gaps in countries with better environment, in particular, more egalitarian countries.

Let's start here: Do you agree that the UK gap, as of 2010, is surprisingly small i.e., between 0 and 0.5 SD for < 15 years old Whites and Blacks? We have converging evidence for this:

normative and birth cohort IQ data
achievement test data

If not, then I have some more digging to do. The things is, this is a lot of work and emailing around, if I'm just going to get B.S. in return.

Let's start here: Do you agree that the UK gap, as of 2010, is surprisingly small i.e., between 0 and 0.5 SD for < 15 years old Whites and Blacks? We have converging evidence for this:

normative and birth cohort IQ data
achievement test data

You already know my answer. I have nothing more to add. It's the strong fact. There is surely lower IQ gap in the UK, and it's not fluke. For the reason, I'm more inclined that the environmental hypothesis is more likely true than HH. But, as you know also, I don't have a good argument, one that theoretically makes sense and is empirically supported. Your argument, if my memory is correct, was that UK blacks may have different attitudes, and the burden of the history of black slavery in the USA is irrelevant to the UK, etc. These are more or less the arguments I favor as well. But these arguments are so speculative, and extremely if not impossible to test, that I don't know what to make of them. From what we know in the USA, black attitudes are unlikely to cause this strong gap in the USA. Obviously, some people can say that what is true in the US is not necessarily applicable to the UK, because they believe the environments are different, etc. A lot of talk. But they still have to prove it. Even the period of desegregation in the US has not caused a secular decline in US gaps, or perhaps only for children. If such strong environmental shift has barely an effect on adult gap, why would I think that the UK is so particularly different than the US ?

Not only is it an Island. It is not a member of the Schengen agreement (open borders). Everybody who travels to the UK gets their passport controlled. This is not the case for e.g. Germany.

One can take the train to the UK from France. http://en.wikipedia.org/wiki/Channel_Tunnel

Yes, I thought everybody knew that it's not a member of the Schengen area. Of course that, coupled with its being an island (the train arrives at a single entry point, whereas countries surrounded by land can be entered by infinite routes (train, car, foot and from any direction)), makes it much easier to select immigrants.