Earlier today commenter “Mugabe” suggested the following thought experiment (I corrected a minor typo):
imagine you had 100 clones and each had been carried by a different gestational surrogate in a different country. and suppose there were 49 other such people like you in this regard.
i don’t find it hard to imagine that there would be norm crossing, that is, that the rank order would not be maintained across countries and that the smallest h^2 (calculated for a pair of countries) would be much smaller than .5.
I agree with Mugabe that in this scenario, the smallest heritability would be much less than 0.5, but I don’t think it matters because if HBD icon Arthur Jensen were alive, I have no doubt he would agree that on a global level, heritability is much lower than the 0.8 figure he liked to cite for countries like America.
The 0.8 correlation between middle aged identical twins raised apart (within countries like America) is controversial, not least because it implies an astonishing 80% of the variation in IQ is “explained” by genes. Taking the square root of the correlation implies that middle aged American IQ would correlate nearly 0.9 with genes! In other words, middle aged American IQ is nearly perfectly genetic.
But as Mugabe would argue, even if older American IQ correlates highly with genes, it doesn’t mean older American IQ is highly independently caused by genes. It could be that Tom has genes that code for an IQ of 120 in America but an IQ of 113 in Africa, and Bill’s genes code for an IQ of 120 in Africa and an IQ of 113 in America. So who is genetically smarter? Tom or Bill.
I have previously suggested that Mugabe’s thought experiment about a sample of people having many clones in many countries could be improved if the IQs of each person’s 100 clones (born from 100 different random wombs in a 100 different diverse countries) could be averaged, and this average would represent a person’s genetic intelligence. Since averaging each person’s 100 clones would cancel out the different reactions each genotype has to different environments, the higher the average IQ of your 100 international clones, the more independent causal high IQ genes or alleles you could claim to have (or the fewer low IQ causing genes/alleles).
So the real debunking of Jensenism would come not from showing that heritability for the entire world (or even just the developed world, or a particular range of countries) is less than 0.5 (no one disputes that), but rather from showing that less than 50% of the variation in older American IQ is independently caused by genes.
That is if a sample of 50+ random Americans each had 100 clones born in 100 random wombs in 100 random countries where they were raised in 100 random homes, and the IQ of each of these 50 Americans and each of their 100 random clones was tested at age 40; if the squared correlation between each American and the average IQ of his 100 clones was less than 0.5, only then could one say HBD and Jensenism have been debunked.
I’m not aware of any HBD proponent ever arguing that environment has no effect. Of course it’s a factor. Phenotype is the result of interaction between genetics and environment. For example, dysentery is very serious in third world countries. It zaps children of energy needed for their brains and bodies to grow. Repeated childhood illnesses not only stunt ones growth but stunt ones intelligence as well. Since people’s immune systems may be more or less suited to certain diseases, what country a clone lives in could potentially make several inches in height and several points in intelligence worth of difference. If one had a more robust immune system and genetics that are less injured by illness they could end up having a higher height and IQ than someone who, in the absence of disease, might have a much higher potential height and IQ. Still, in the absence of such diseases, such as the case in first world countries, one sees that potential height and IQ is not limited by disease but by genes. What this really boils down to is that in any given environment genetics is still the most important factor.
http://www.wsj.com/article_email/SB10001424052702304898704577478482432277706-lMyQjAxMTAyMDIwNDEyNDQyWj.html
Environment is no factor in the normal range
you’re too retarded to post kevin.
twin studies are shit because all the twins have A LOT of OTHER THINGS in common.
they’re born at the same time in the same place and usually raised near each other in the same country.
and what about twins reared apart?
I’m not aware of any HBD proponent ever arguing that environment has no effect. Of course it’s a factor. Phenotype is the result of interaction between genetics and environment.
Everyone agrees environment is a factor, but the implicit assumption of most HBDers seems to be that there’s an absolute genetic hierarchy. The message of Jensenism was not that whites are genetically smarter than blacks when reared in modern America,it was simply whites are genetically smarter than blacks. Full stop. Because Jensen never qualified it, he seemed to be implicitly saying that when blacks and whites are reared in the same environment, whites will have more general intelligence, regardless of what environment they are reared in.
Of course if whites are reared in a terrible environment and blacks are reared in a great environment, Jensen would have agreed that blacks could have higher IQ than whites, but that’s different from saying environments exist where blacks would have higher IQ than whites within that same environment.
In other words, Jensen viewed the genetic effect as a constant independent causal variable. He implicitly endorsed the Phenotype = Genotype + Environment assumption.
So regardless of whether the environment was so great that whites scored 120 or so bad that whites scored 70, blacks in the same environment would always score about one standard deviation lower.
Of course this assumption might be mostly true. The black-white IQ gap in the U.S. has remained about 15 points for the last 100 years or so, even as the average test performance of both races has increased by 30 points over the same time period. Interestingly, a parallel increase has occurred for height. Of course the U.S. is only one country, but Michael Hart would argue that blacks have been culturally behind caucasoids for tens of thousands of years.
Dude
Since it’s a hypothetical example, why limit the environments to Earth? Perhaps there are planets where Swank is my intellectual equal instead of 80 IQ points dumber.
why not? the effect can’t be known. that’s the only reason. why? because compared to 1900 the modern world IS science-fiction.
i’m not laughing with you. i’m laughing at you.
if country X has a much lower mean score than country Y this has no effect on the heritability calculation for pairs where one is in country X and the other in country Y. it’s just that the regression line doesn’t pass through 0. but if you wanted you could simply assign z scores rather than absolute scores. the z score would be for the respective country.
the h^2 for the two most unrelated countries will be much less than .5, but for Norway vs Sweden there wouldn’t be any difference.
furthermore the differences that matter aren’t likely to be in the physical environment, but in the social environment. and such differences ARE 100% of the explanation for the Flynn Effect…according to Flynn…and me.
the IQ wouldn’t be 113 in Africa. it would be more like 90…30 points lower. only fucktards like Lynn think that IQ test scores mean the same thing on the Upper East Side and in Darfur. black Africans today and whites in 1900 scored the SAME. AND present day Africa is A LOT shittier IN EVERY WAY than 1900 in the West.
black Africans today and whites in 1900 scored the SAME. AND present day Africa is A LOT shittier IN EVERY WAY than 1900 in the West.
If that’s true, that would indeed debunk the P = G + E assumption, and I’ve been planning on devoting a post to this exact topic very soon because it’s bothered me for years. But it might not be 100% true.
Did you ever write a post on this?
Ross implies the gap would disappear if conditions were very poor. Let’s consider this. Giving a 3rd world population 1st world conditions would likely reduce the gap between the 1st and 3rd world populations. Similarly, giving a 1st world population 3rd world conditions would likely reduce the gap. But similar conditions are unlikely to produce near parity regardless of how good those conditions are. As evidence, there was a 1 stdv gap between different populations in 1900s America and there’s a 1 stdv gap between different populations in present day America. The average has increased along with improved conditions, But the gap has remained nearly unchanged. Going the other way, the kind of conditions that exist in 3rd world countries still hasn’t resulted in parity even though the average for populations with lower potential is borderline retardation. Just how poor do conditions have to be to result in parity? If they haven’t achieved parity at near 70 that suggests parity might be found at what? An IQ of 60 or 50? I would suggest that conditions bad enough to result in parity would have to be artificially created and forcibly imposed because, no matter how poor conditions are, those with higher potential will use their higher potential to better themselves. Of course, those with lower potential will as well. but they won’t be as good at it.
i don’t know who ross is, but i certainly DID NOT IMPLY THAT.
destructure clearly DOES NOT UNDERSTAND.
i just threw in that factoid about the FE and Africa. i have no interpretation for it or implication for it. it was just an example of how IQ tests aren’t like brain scans or craniometry or whatever.
black Africans if they had been raised in Norway would not score 70 on their IQ tests.
and the idea that half of black Africans are mentally retarded is so laughable that even Rushton felt the NEED to explain it. Rushton “explained” it away by saying black Africans weren’t retarded, they just had the minds of children. huh? what?
Even Charles Murray states that the gap was 1.5 SD in the 1920’s. Black head size has increased since 1900. So, I’m not sure why the gap wouldn’t have been even greater in 1900. The fact that the gap is smaller now than it was then suggests that blacks have seen a larger IQ increase than whites under FE.
Murray is probably wrong. The first mass IQ testing in WWI found only a gap of 1 SD.
“Even Charles Murray states that the gap was 1.5 SD in the 1920’s.”
You didn’t provide an actual citation. But it doesn’t matter. In spite of claims to the contrary, the gap hasn’t really changed in decades.
“I’m not sure why the gap wouldn’t have been even greater in 1900.”
Let me know when you’re sure.
Black head size has increased since 1900.
So has white head size.
Yes, on a different test on an unrepresentative sample. Murray’s data is based on three administrations of the same test over time with representative samples.
The WWII army testing data is also consistent with Murray’s conclusion, not the WWI 1SD.
Incidentally, the WWI test also showed that black northerners outperformed white southerners.
I know it has. That’s the point. If you associate the general gains in IQ with that increase, then that increase started, or at least was underway, in 1900…which means it’s not unreasonable to assume that the gap wasn’t even larger at that time.
I’m not sure how many decades destructure is talking about. Two or three, sure. Five or six, I know Murray says as much. Greater than that is a minority view.
the WWI test also showed that black northerners outperformed white southerners.
you should give a link for that. HBDers would have to say: You sunk my battleship!
Charles Murray’s sample could just as easily be dismissed as unrepresentative. Jensen says the black-white IQ gap has remained 1 SD for the past century, but he also thinks it’s possible that it’s remained 1.5 SD for the past century. Either way, he felt it’s remained virtually unchanged.
i’ve said it before and it fell on deaf ears perhaps but…
although it is much less politically acceptable in heterogeneous societies it is much MORE likely that there is no norm crossing for group mean performance that that there is no norm crossing for individuals.
the reason is simply that individual norm crossing is wiped out when millions of people’s scores are averaged.
but in the US and in the HBD-sphere there is a confusion of matters of race and matters of social stratification. there is confusion between what is true of groups and what is true of individuals.
that is, it is much MORE likely that some groups/races will always underperform and others outperform on average/as a group, than it is that the poor and down trodden individual genome or the rich and powerful individual genome would never switch places under any circumstances.
that is, hereditism is much better at explaining racial disparities than it is at explaining class structure. and this is simply a mathematical fact not an empirical fact.
Scores on AEF intelligence tests, WWI, look at page 18:
Incidentally, this pamphlet was banned for containing this information, and labeled as “subversive.”
Here’s another recounting of literature ~1950’s showing similar trends and addressing the selective migration theory:
(first article)
although it is much less politically acceptable in heterogeneous societies it is much MORE likely that there is no norm crossing for group mean performance that that there is no norm crossing for individuals.
the reason is simply that individual norm crossing is wiped out when millions of people’s scores are averaged.
This is an excellent point and good of you to concede a point favoring a perspective you generally oppose. I’ve actually thought of a similar point in the context of individuals. That is even if an individual has a gene that makes him smart in environment A and dumb in environment B, it might be cancelled out by a gene that makes him smart in environment B and dumb in environment A
correlation of X and Y is the same as correlation of X and Y + a constant.
h^2 is the correlation of scores for pairs of identical twins…or rather this is the most direct way of estimating it.
so as long as country’s X’s twins’ scores are assigned to the x axis and country Y’s to the Y axis the correlation, and thus h^2, shouldn’t change according to the P = G + E model. it’s just that the regression line doesn’t go through the origin because the difference in Es isn’t on average equal to 0.
of course if twins from X and Y were assigned at random to the x axis or the y axis then the h*2 would be much less.
Maybe I’m misunderstanding, but it sounds like you’re assuming everyone in country A has the exact same environment and everyone in country B has the exact the same environment, and ignoring the fact that the clones would be randomly scattered within A and B. Or at least that was my interpretation of your thought experiment.
if the P = G + E model is followed, it shouldn’t matter as long as the within country variance is about the same. but obviously comparing a big heterogeneous country like the US to say Manaco would result in an h^2 which was less than Monaco’s.
it’s never mentioned but h^2 can be increased or decreased simply by rearranging which twins’ scores are assigned to x and which to y.
so it isn’t even clear that a global h^2 can be defined unambiguously. all that can be done perhaps is compare pairs of countries with one twin in each and give a range for h^2.
if the P = G + E model is followed, it shouldn’t matter as long as the within country variance is about the same. but obviously comparing a big heterogeneous country like the US to say Manaco would result in an h^2 which was less than Monaco’s.
So if we had 50 random Americans, each with an identical twin raised somewhere in Rwanda, would a correlation > 0.5 be enough to convince you HBD is correct?
it’s never mentioned but h^2 can be increased or decreased simply by rearranging which twins’ scores are assigned to x and which to y.
so it isn’t even clear that a global h^2 can be defined unambiguously. all that can be done perhaps is compare pairs of countries with one twin in each and give a range for h^2.
Wouldn’t it just be done randomly?
if the P = G + E model is followed, it shouldn’t matter as long as the within country variance is about the same. but obviously comparing a big heterogeneous country like the US to say Manaco would result in an h^2 which was less than Monaco’s.
You’re confused. It would matter LOTS! If you had 50 Americans all raised in the same American house and their 50 Rwandan identical twins all raised in the same Rwandan house, then under the P = G + E model, the correlation between them would be PERFECT.
But if you had 50 Americans randomly scattered through America and their 50 identical twins randomly scattered through Rwanda, then under the P = G + E model, the correlation should be > 0.5.
I’m more intelligent than you.
I need to join the BGI study!
you’re a JOKE pp. and your blog is a JOKE.
more intelligent than me? not in IQ terms or any other.
going to join the BGI study? you can’t! you’re at least 90 points below the cutoff.
pp you’re too fucking retarded to understand how fucking retarded you are.
i’m confused?
I’M confused?
it’s math pp.
you’re too dumb to understand it.
You’re definitely confused, and definitely less intelligent than me.
If everyone in country A had the exact same environment, then under the P = G + E model, the correlation between P and G in country A would be perfect because environmental variability would be zero.
If everyone in country B had the exact same environment, then under the P = G + E model, the correlation between P and G in country B would also be perfect because environmental variability would be zero there too.
Thus clones separated into countries A and B would correlate perfectly in P, because by definition, they have identical G, and P and G correlate perfectly in their respective countries.
However if environment varied within countries, then P and G would have imperfect correlations within countries, and clones separated between the countries would have squared imperfect correlations, making said correlations even more imperfect.
Got it?
Can birds fly higher than pigs? Not necessarily…
you’re confusing person A being dumber than person B with person A being retarded.
who thinks that retards just need a better environment? no one.
There are tests to prove birds can fly higher, tests that would be dispositive. They just haven’t been carried out.
I however think that if you took pairs of one bird and one pig, and let them fly in atmospheres of different densities, and varying gravitational fields, then WOULD find norm-crossings disproving the claim.