The Impact of Genetic Heritability on Intelligence: Fact or Fiction?

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The discussion centers around the heritability of intelligence and its implications for race and societal structures. Professor Jensen's research suggests that the heritability of IQ increases with age, paralleling findings in physical traits like height. Concerns are raised about how this information might be misused, particularly regarding eugenics and potential oppression of minority groups. The conversation also touches on the need for a humane approach to education and policy, emphasizing that knowledge should be integrated thoughtfully to avoid negative societal impacts. Ultimately, the dialogue highlights the complexities of addressing intelligence differences while advocating for equitable treatment across racial lines.
  • #31
hitssqud wrote: That latter extrapolation is in keeping with Richard Lynn's prediction (from his book Eugenics: A Reassesment) that China -- because of its population's present characteristic IQ and because of its population's characteristic temperament which allows for state-controlled eugenics -- will soon become the world's sole superpower.
--
As China gains supremacy over Europe in economic, scientific, and military strength sometime in the second half of the twenty-first century, China can be expected to use its power to take control of the world and establish a world state.[/color]
You don't need any of this scary stuff, simple global free trade and an open economy (plus 1.2 billion people) will ensure that China gets bigger than the US economically (with India following a decade or two later).

The rest seems to me like what I understand psychologists call "projection" - it's what Lynn would do if he were Hu Jintao's successor.

A more detailed study of Chinese culture might lead a different scholar to a very different conclusion.
 
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  • #32
Nachtwolf wrote: But I am especially in favor of voluntary eugenics such as free mate choice, genetic counselling, and personal decisions about how many children to have, and I am also in favor of certain low-key governmental programs such as socialized (free, widely and easily available) birth control, immigration reform, and public announcements.
Didn't I see that you also thought removal of all 'hate laws' would be a good idea, ditto a return to segregated schools (in the US), banning all conjugal visits to prisoners (or was it only blacks?), significant welfare reform, and (I'm not so sure of this) redistribution of spending on public education, away from schools for poor blacks to rich whites?
 
  • #33
Geographical restrictions on the expression of the g nexus

Originally posted by Nereid
You don't need
...the g nexus?...





simple global free trade and an open economy (plus 1.2 billion people) will ensure that China gets bigger than the US economically (with India following a decade or two later).
Assuming that the g nexus is operable in the United States, why would it not be operable in the rest of the world?

China's genetically characteristic high IQ, and India's genetically characteristic IQ terminating at below the mental age of the average 13 year old British child, do not effect the respective probabilities for China's and India's respective economic outcomes? Yet IQ does effect relative outcome between American cities and American states? How could this be?





-Chris
 
  • #34
hitssquad wrote:
China's genetically characteristic high IQ, and India's genetically characteristic IQ terminating at below the mental age of the average 13 year old British child, do not effect [sic; I think hitssquad means 'affect'] the respective probabilities for China's and India's respective economic outcomes? Yet IQ does effect [sic; harder to say; both 'affect' and 'effect' could be what hitssquad means] relative outcome between American cities and American states? How could this be?
Well, for a start, I don't think it's been established what the 'genetically characteristic IQ' of either economy is.

First, there's still an open 'Stats-101' question about the data Lynn and Vanhanen used - and the conclusion they reached - re 'China' and the dominant population group (Han Chinese).

Then, for me at least, a set of open questions on L+V's methods.

Third, the Wipro reality check (see the other thread) - I understand Wipro is not a sport, nor managed by white Americans (and certainly not by Han Chinese!); there're a rather a lot of Indian software companies, producing absolutely world-class products. (But then, maybe 13 year old British kids are pretty good hackers? Well, last time I looked, the Indians among them certainly could be :wink:).

Fourth, my toy research - city living all but guarrantees smarts.
hitssquad wrote: Assuming that the g nexus is operable in the United States, why would it not be operable in the rest of the world?
This is a really good question . I've got some ideas; ttul. :smile:
 
  • #35
Does living in a wealthy country force expression of high IQs

Originally posted by Nereid
city living all but guarrantees smarts.
Then we are left with the questions of why:


1. within the United States, heritability of IQ has been found to be high.

2. children rescued from adversity, both moderate and severe, tend to fall into a normal distribution of IQs.
http://www.google.com/search?q="children+rescued+from+adversity"

3. Chinese have high IQs despite China's poor environment (Chinese heat their homes with coal buring inside the home; much of the population lacks an education, viz literacy is only at 86%).

4. wealthy, urbanized oil and resort nations have low IQs.





-Chris
 
  • #36


Originally posted by hitssquad
Then we are left with the questions of why:

1. within the United States, heritability of IQ has been found to be high.

2. children rescued from adversity, both moderate and severe, tend to fall into a normal distribution of IQs.
http://www.google.com/search?q="children+rescued+from+adversity"

3. Chinese have high IQs despite China's poor environment (Chinese heat their homes with coal buring inside the home; much of the population lacks an education, viz literacy is only at 86%).

4. wealthy, urbanized oil and resort nations have low IQs.
These are, of course, very good questions.

However, the second two require us to first have to hand good data on the IQs of many, many groups of people in many countries. Such data may exist; however, it's not to be found in Lynn and Vanhanen's " Intelligence and the Wealth and Poverty of Nations".

Let's do some toy research anyway. Let's take L+V's "National IQ" for rich North American (Canada, US), European (Belgium, Denmark, Finland, France, Germany, Ireland, Italy, Netherlands, Portugal, Spain, Switzerland, UK), and Asia-Pacific economies (Australia, Hong Kong, Japan, New Zealand, Singapore). I've already established, using L+V's reported data, that there's no correlation between National IQ and 1998 real per capita GDP ('wealth' for shorthand).

What about wealth and urbanisation? No correlation.

How about National IQ and urbanisation?
~57% correlation!

Of course, this is toy research, and almost all the correlation is accounted for by two data points - Ireland (IQ 87, urbanisation 6) and Portugal (91, 5.8); Finland (the other low urbanisation nation (also 6) has the same IQ as the US (98), is the outlier (must be all those Lapps ... oops! Lapps are closest to SE Indians genetically, and nearest Indians on the PC plane ... and they have IQs of ... er, oh dear)
 
  • #37
why the g-nexus may not be generalisable

hitssquad wrote: Assuming that the g nexus is operable in the United States, why would it not be operable in the rest of the world?
First thing to make very clear: if we're doing science, we can't assume it operates outside the region it has been shown to work*, we have to do the hard work to demonstrate clearly and unambiguously that it does.

Let's start with g. Is it tied to biology?[/color] No. As quite a number of the threads here (http://psycprints.ecs.soton.ac.uk/archive/00000699/ ) make clear, a) g is an operational construct (briefly "g measures the ability to do well at tests"), not a theoretical one (e.g. within Pinker's neuroplastic theory of meta-linguistic ability, g is an outcome of hyper-language fixation - that's not real, I made it up); and b) research results showing a biological link are far from being well-established. This means that, short of doing the same extensive research that Jensen et al did in the US in every other region of the world, we have no basis for thinking a generalisation will be true (equally, none for thinking it would not).

Is g 40 to 80% hereditable?[/color] Among US 'blacks' and 'whites', it may be*; among some samples of folk in 50's and 60's England (and Wales?), it may be. However, without unequivocal identification of 'g genes' or detailed studies into g's hereditability in the thousands of ethnic groups throughout the world, it's an open question.

Next, the g-nexus.
Criminals[/color]. A study of the g-nexus in China in 1959 would likely have shown a high correlation between prisoners and g ... the smarter folk were disproportionately represented within the prison population. The same may be true in Cuba today. Of course we immediately dismiss this as a serious counter to the g-nexus; but what not-so-obvious variations of this might be at work? What's the g profile of the ~600 people in Guantanamo Bay? The inmates of the Woomera Detention Centre?

SES (social and economic success)[/color]. In many countries of the world, we can be very, very certain of the primary factor in SES - gender. If you're a woman in many (most? all?) of the Middle East nations, your g plays no significant part in your SES. The same is undoubtedly true in Lynn's poster children - Japan and S Korea. In many other countries, other factors are clearly important if not necessarily of primary importance - caste (e.g. India), physical strength (e.g. rural areas in developing countries), general disease resistance (ditto), birthplace (e.g. China; under the hukou system, if you're born in 'the countryside', you can't go live in a city; the good news is that this is breaking down).

What else? IMHO, it's probably worth looking at language (e.g. tonal vs atonal), writing (e.g. ideographic vs phonemic), family traditions (e.g. behaviours and values exhibited in early childhood), behaviour of mothers in early childhood, and birth order and spacing (didn't I read that the US decline in average SAT scores was laid at the feet of younger siblings?).

*Note: I'm not saying that it does/is; I'm merely examining the logical consistency.
 
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  • #38
Originally posted by Nachtwolf
Because you personally are intolerant of certain words, and feel the need to burden others with your emotional baggage?


--Mark
You are making incorrect assumptions. I am not offended. I was merely pointing out your obvious lack of intellect.
 
  • #39
Nereid,

g is an operational construct (briefly "g measures the ability to do well at tests"),

is an inaccurate way to characterize g. "A systematic propensity to do better on some test questions than others, found to persist across individuals and populations in the US and Britain" would be better, and not weaken your argument.

Secondly your insistance (made in several different ways in several posts) that US and British evidence tells us nothing about non-anglo populations or selected subgroups, is a little weak. In science we do make "uniformitarian" assumptions, sometimes quite strongly. We assume physics is the same in the solar system as in the remote galaxies, for example. I am quite sensitive to your points about Chinese prisoners, hypothetical Cuban prisoners, and Guantanamo detainees, and I think they would make interesting case studies, but can't believe any consequence of those studies would much affect the broad populational results which have been developed.
 
  • #40
SelfAdjoint wrote: Secondly your insistance (made in several different ways in several posts) that US and British evidence tells us nothing about non-anglo populations or selected subgroups, is a little weak. In science we do make "uniformitarian" assumptions, sometimes quite strongly. We assume physics is the same in the solar system as in the remote galaxies, for example. I am quite sensitive to your points about Chinese prisoners, hypothetical Cuban prisoners, and Guantanamo detainees, and I think they would make interesting case studies, but can't believe any consequence of those studies would much affect the broad populational results which have been developed.
Some time ago, back in Physics (or was it Astronomy and Cosmology) I started a discussion on just the question of 'how do we know that the physics we do in our labs here is the same as that in remote galaxies'. The point is that we *don't* assume it's the same, we are continually doing experiments and making observations to be sure that it is (as much as anything can be sure of anything in science). For example, there's a lively debate about whether the speed of light is constant, and has always been constant (the question is far better addressed through the fine structure constant than c).

When it comes to g, which has no theoretical basis (unlike what we do in physics, mostly) and no biological links, it seems to me that generalisation should be demonstrated, concretely, step-by-step.

However, the more important limitation is on the g-nexus; the g factor's importance (going up) in explaining/accounting for/predicting/etc SES, criminality, child abuse by welfare Moms, the wealth and poverty of nations, ... (and going down), its hereditability etc.

Finally, there's the 'race' component in the g-nexus. As is discussed on another thread, Jensen's work was built on a concept of race that is clearly peculiar to the US (and highly unlikely to be generalisable in any meaningful sense) - self-reporting, and only two 'races' studied ("Black" and "White").
 
  • #41
The present situation in astrophysics and cosmology is dependent up many recent breakthroughs in technologies, such as observation from satellites. Back when Einstein was in his prime, or even Feynman (which I remember well), these things that are now discussed in falsifiable manner were simply assumed to be so, and the reason given was uniformaitarianism. Some day g will be tested in all the venues you desire and more, but till then it is still a valid construct.

On the black and white issue, you say his evidence was collected on the basis of race. In fact it was collected on the basis of self identification in one of two long standing little interbreeding (at that time) populations in the US. He may have used the word race but nothing in his work depended on any of the racial beliefs of the time. The differential sociology of these populations was and is a large study, and he had data on the different social and econmoc classes within the two populations.
 
  • #42
SelfAdjoint: Back when Einstein was in his prime, or even Feynman (which I remember well), these things that are now discussed in falsifiable manner were simply assumed to be so, and the reason given was uniformaitarianism.
This is very interesting, and well worth a good discussion in Astronomy & Cosmology. For now I merely note that helium was discovered in the spectrum of the Sun 25 years before it was found on Earth, and that Dirac's prediction of the positron was followed 4 years later by Anderson's discovery ... in cosmic rays.
SelfAdjoint: Some day g will be tested in all the venues ...
It may be that g is relatively unexceptional; what I am more concerned about is the baggage it has accumulated - the g-nexus - g and race, g and crime, g and SES, g and national wealth and poverty ...
SelfAdjoint: On the black and white issue, you say his [Jensen's] evidence was collected on the basis of race. In fact it was collected on the basis of self identification in one of two long standing little interbreeding (at that time) populations in the US. He may have used the word race but nothing in his work depended on any of the racial beliefs of the time. The differential sociology of these populations was and is a large study, and he had data on the different social and econmoc classes within the two populations.
It would seem that Jensen himself studiously avoided the term 'intelligence', feeling that it was too overloaded with different meanings and associations. Curiously, he seems to not have had the same qualms with 'race', where self-identification hardly constitutes a reliable basis (except perhaps as a social group), where the biology of period was unequivocal as to its unreliability, and where there was ample evidence of the historical extent of interbreeding and the contemporaneous trends (the US Census Bureau's data was publicly available, and the trends hard to miss).

To reinforce this last point, perhaps someone au fait with population statistics could tell us quickly what degree of gene mixing we could expect among two groups:
A: breeds within its group and with group B; all progency considered to be group A, 10% of all breeding is inter-group
B: breeds within its group and with group A; 5% of all breeding is inter-group, all inter-group progency considered to be group A.

Caveat: these comments apply more to the period from 1980 than post-World War II to 1980. However, "Guess Who's Coming to Dinner" is a 1967 film (not that Hollywood should be considered serious science!)
 
  • #43
Interbreeding and its discontents

Originally posted by Nereid
It would seem that Jensen himself studiously avoided the term 'intelligence', feeling that it was too overloaded with different meanings and associations. Curiously, he seems to not have had the same qualms with 'race', where self-identification hardly constitutes a reliable basis,
As far as a statistical viewpoint is concerned, statistical methods quantify reliability. Statistical methods applied to instances of self-identification of racial categories return quantifications of reliability in those instances.

Unreliability in an instance of racial self-identification would imply, over the lifetimes of a substantial portion of individuals in the populations under study, systematic inconsistency in the answering of the institutionally-posed race-category question. E.g., a given unreliably-self-identifying individual may claim to be black one year, white the next, then asian, then American Indian, etc.





where the biology of period was unequivocal as to its unreliability,
Lack of discrete knowledge of the inner workings of biology is noticably unreliable in its hindering of the reaching of reliable and valid conclusions.





and where there was ample evidence of the historical extent of interbreeding
Interbreeding is one of the modes of race generation and is consistent with the realities of statistically-defined sets. It does not conflict with race or racial categorization.


--
a race is one of a number of statistically distinguishable groups in which individual membership is not mutually exclusive by any single criterion, and individuals in a given group differ only statistically from one another and from the group's central tendency on each of the many imperfectly correlated genetic characteristics that distinguish between groups as such. The important point is that the average difference on all of these characteristics that differ among individuals within the group is less than the average difference between the groups on these genetic characteristics. [/color]
--
(The g Factor. p425)
http://www.questia.com/PM.qst?a=o&d=24373874





and the contemporaneous trends (the US Census Bureau's data was publicly available, and the trends hard to miss).
What contemporaneous trends are referred to here?





what degree of gene mixing we could expect among two groups:
A: breeds within its group and with group B; all progency considered to be group A, 10% of all breeding is inter-group
B: breeds within its group and with group A; 5% of all breeding is inter-group, all inter-group progency considered to be group A.
In the first instance, group A's progeny end up bearing an average of 5% of group B's markers.

In the second instance, group A's progeny end up bearing an average of 2.5% of group B's markers.





-Chris
 
  • #44
hitssquad: Unreliability in an instance of racial self-identification would imply, over the lifetimes of a substantial portion of individuals in the populations under study, systematic inconsistency in the answering of the institutionally-posed race-category question. E.g., a given unreliably-self-identifying individual may claim to be black one year, white the next, then asian, then American Indian, etc.
Well there's some indication that precisely that may be happening: 2.4% of respondents in the 2000 Census gave 'more than one race' as their race (the first time this was allowed); the 'other race' category rose from 0.3% in the 1970 census to 5.5% (more if you count the 'more than one race' responses) in 2000. Of course, without access to the individual records, there would appear no way to tell, from the Census data, how many folk changed their 'race' between censuses.
hitssquad: Lack of discrete knowledge of the inner workings of biology is noticably unreliable in its hindering of the reaching of reliable and valid conclusions.
Translation: not knowing how the biology works can sometimes mean your conclusions are unreliable and invalid, other times it doesn't seem to matter; before you find out the biological mechanisms you cannot be sure which it will be. Yes/No/Other?
hitssquad: Interbreeding is one of the modes of race generation and is consistent with the realities of statistically-defined sets. It does not conflict with race or racial categorization.
There are at least two important caveats: if there are factors which vary continuously (or nearly so) across the whole population, the distributions about the means of each subset are unlikely to be Gaussian, and you should be able to recover the continuous distribution from statistical analysis. What does Jensen have to say on these points?
hitssquad: What contemporaneous trends are referred to here?
Inter-racial marriage. AFAIK, laws against black-white marriage (or all inter-racial marriage?) were declared unconstitutional in the US only in 1967; Census Bureau data shows a) a fairly swift rise in black-white marriages, at least from 1970, and b) >8 white-black marriages for every 100 black-black marriage (in 2002).
hitssquad: In the first instance, group A's progeny end up bearing an average of 5% of group B's markers.
Sorry, I wasn't clear. I meant, given reasonable assumptions, how quickly would virtually all members of Group A have at least one Group B ancestor? My small envelope says as few as 4 generations.
 
  • #45
Racial admixture study in Germany - no IQ/race relationship?

From http://psycprints.ecs.soton.ac.uk/archive/00000692/ :

"... Jensen dismisses data from a racial admixture study in Germany which found no significant or consistent differences in IQ with race, because parental IQ was unknown, and because white and black fathers were not randomly sampled, two faults shared with the Minnesota adoption study. The absence of differences in the German study is also consistent with a maternal effects hypothesis, since the mothers were all white."

What is the German study?

What studies have been done into the material effects hypothesis?
 
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  • #46


Originally posted by Nereid
What is the German study?
Now here's a great question.

The German study was a done on the bastard children of American WWII officers and German woman, and Jensen doesn't dismiss it for those reasons you quoted alone.

Referring to his book, The g Factor, I note that the study was done in 1959 on almost 400 children, 194 white and 193 mixed race children. The IQs are as follows:

White Boys: 101 IQ
White Girls: 93 IQ
Mixed Boys: 97 IQ
Mixed Girls: 96 IQ

As you can see, there is no important difference in the averages between the White and Mixed groups. Here are the objections he presents on page 483 of The g Factor, summarized:

1. The fathers were not representative of their respective populations, "since 30 percent of blacks, as compared with about 3 percent of whites, failed the preinduction mental test and were not admitted into the armed services." (In other words, the blacks had a higher-than-average IQ, probably closer to 95 than 85.)

2. Nothing is known about the army rank of the fathers. (This strikes me as mere quibbling.)

3. The children were tested before adolescence, which is before the genotypic aspect of IQ has become fully manifested.

4. Heterosis (or hybrid vigor) probably enhanced the IQ of these first generation mixed race children. (Heterosis has in other instances been seen to raise IQ scores by 2 to 4 points.)


In other words, Jensen's Default Hypothesis would predict, using the information we have at our disposal, an IQ gap on the order of 1 IQ point, while the environmental hypothesis would predict an IQ gap of 0 IQ points. These two predictions are so close that the test is unable to vindicate one and falsify the other and was, essentially, a waste of time.

What studies have been done into the material effects hypothesis?
This is a good question, and I cannot answer it. Chris might be able to, however.


You are making incorrect assumptions. I am not offended. I was merely pointing out your obvious lack of intellect.
Hello Evo. Please explain, in fifty thousand words or less, how my refusal to bow before idiotic standards of political correctness which are quite mindlessly embraced by sheeple such as yourself marks me as an individual with a "lack of intellect."

When considering your answer, Evo, pay careful attention to these objective test results:

This report compares Mark W. Henshaw from the country USA to other men between 21 and 40 years of age.

...

..Intellect...87 (Out of 100)

Intellect and artistic interests are the two most important, central aspects of openness to experience. High scorers on Intellect love to play with ideas. They are open-minded to new and unusual ideas, and like to debate intellectual issues. They enjoy riddles, puzzles, and brain teasers. Low scorers on Intellect prefer dealing with either people or things rather than ideas. They regard intellectual exercises as a waste of time. Intellect should not be equated with intelligence. Intellect is an intellectual style, not an intellectual ability, although high scorers on Intellect score slightly higher than low-Intellect individuals on standardized intelligence tests. Your level of intellect is high.


--Mark
 
  • #47
Minnesota yes, Germany no?

Do you have a reference to the German study Nachtwolf?

Would you care to counterpose the Minnesota transracial adoption study with the German study?

Here's a quote from the same source as my previous quote; you may wish to consider this as your draw up the comparison table:

"Jensen's "default hypothesis" is that differences in white and black IQ scores are made up of genetic and environmental effects and that environmental effects are often small relative to genetic effects (e.g. pp. 177-175, 475, 476, 489). These conclusions seem best supported by estimates of heritability [...] and from the Minnesota transracial adoption study. This adoption study has several flaws. Maternal effects were not considered as a serious possibility for the lower IQ of blacks relative to whites. The IQ of parents of adopted children was unknown. The mean age of adopted infants also differed between treatment groups. And most fundamentally, the parents of children were not selected randomly from the population. Infants of parents of varying socioeconomic status and race might give children up for adoption, or have them taken into care, for very different reasons.[/color]"
 
  • #48


Originally posted by Nereid
Do you have a reference to the German study Nachtwolf?
Sprechen Sie Deutsch, Nereid?



--
Black-White Hybrids in Post-World War II Germany. We saw in the Minnesota Transracial Adoption Study that the interracial (BW) adoptees, whose biological fathers were black and whose biological mothers were white, averaged lower in IQ than the adoptees who had two white parents (WW). (See Table 12.5 , p. 474.) This finding appears to be at odds with the study conducted by Eyferth [^{68}] in Germany following World War II, which found no difference between offspring of BW and WW matings who were reared by their biological mothers. All of the fathers (black or white) were members of the U.S. occupation forces stationed in Germany. The mothers were unmarried German women, mostly of low SES. There were about ninety-eight interracial (BW) children and about eighty-three white children (WW). The mothers of the BW and WW children were approximately matched for SES. The children averaged about 10 years of age, ranging between ages 5 and 13 years. They all were tested with the German version of the Wechsler Intelligence Scale for Children (WISC). The results are shown in Table 12.6. The overall WW-BW difference is only one IQ point. As there is no basis for expecting a difference between boys and girls (whose average IQs are equal in the WISC standardization sample), the eight-point difference between the WW boys and WW girls in this study is most likely due to sampling error. But sampling error does not only result in sample differences that are larger than the corresponding population difference; it can also result in sample differences that are smaller than the population difference, and this could be the case for the overall mean WW-BW difference.

This study, although consistent with a purely environmental hypothesis of the racial difference in test scores, is not conclusive, however, because the IQs of the probands' mothers and fathers' were unknown and the white and black fathers were not equally representative of their respective populations, since about 30 percent of blacks, as compared with about 3 percent of whites, failed the preinduction mental test and were not admitted into the armed services. Further, nothing was known about the Army rank of the black or white fathers of the illegitimate offspring; they could have been more similar in IQ than the average black or white in the occupation forces because of selective preferences on the part of the German women with whom they had sexual relations. Then, too, nearly all of the children were tested before adolescence, which is before the genotypic aspect of IQ has become fully manifested. Generally in adoption studies, the correlation of IQ and genotype increases between childhood and late adolescence, while the correlation between IQ and environment decreases markedly. (The respective correlations are the square roots of the heritability, \sqrt{H^2}\\, and of the environmentality, \sqrt{1-H^2} = \sqrt{E^2}\\.) Finally, heterosis (the outbreeding effect; see Chapter 7, p. 196) probably enhanced the IQ level of the interracial children, thereby diminishing the IQ difference between the interracial children and the white children born to German women. A heterotic effect equivalent to about +4 IQ points was reported for European-Asian interracial offspring in Hawaii. ^{69} [/color]
--
The g Factor. pp482-483.
http://www.questia.com/PM.qst?a=o&d=24373874



--
68. Eyferth, 1959, 1961; Eyferth et al., 1960. This study is described in some detail by Loehlin et al., 1975. Flynn (1980, pp. 219-261) offers a quite detailed summary and analysis of the study in support of his view that it probably constitutes the strongest of what he terms "direct" evidence against the hypothesis that the mean W-B IQ difference has a substantial genetic component.

69. Nagoshi & Johnson (1986) reported g factor scores averaging .26\sigma\\ higher for interracial European-Asian offspring than for the offspring of same-race parents who were matched with the interracial parents in education and SES. Heterosis was greater on the more highly g-loaded tests; the vector of heterotic effects on fifteen tests correlated +.44 (p = .10) with the vector of the tests' g loadings. [/color]
--
Ibid. pp526-527.
http://www.questia.com/PM.qst?a=o&d=24373874




Eyferth K. (1959). Eine Untersuchung der Neger-Mischlingskinder in Westdeutschland. Vita Humana, 2, 102-114.

Eyferth K. (1961). Leistungen verschiedener Gruppen von Besatzungskindern in Hamburg-Wechsler Intelligenztest für Kinder (HAWIK). Archiv für die gesamte Psychologie, 113, 222-241.

Eyferth K., Brandt U. & Hawel W. Farbige Kinder in Deutschland. München: Juventa Verlag.

Flynn J. R. (1980). Race, IQ and Jensen. London: Routledge & Kegan Paul.

Loehlin J. C., Lindzey G. & Spuhler J. N. (1975). Race differences in intelligence. New York: W. H. Freeman.

Nagoshi C. T. & Johnson R. C. (1986). The ubiquity of g. Personality and Individual Differences, 7, 201-208.



(References are quoted from The g Factor. The g Factor omitted the date from the Eyferth et al. reference. Footnote 68, above, implies it should be 1960.)


Nachtwolf already reproduced the IQ data from Table 12.6 Mean WISC IQ of Black Interracial Children (BW) and of White Children (WW) of German Mothers. Here it is again, for convenience:


White Boys: 101 IQ
White Girls: 93 IQ
Mixed Boys: 97 IQ
Mixed Girls: 96 IQ[/color]



[Edit: added a parenthesis and corrected a page number citation] [/color]


-Chris
 
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  • #49
  • #50


To give a more specific analysis:

This adoption study has several flaws.
Certainly. Scarr & Weinberg admit that no study is perfect.

Maternal effects were not considered as a serious possibility for the lower IQ of blacks relative to whites.
Maybe not.

The IQ of parents of adopted children was unknown.
Indeed.

The mean age of adopted infants also differed between treatment groups.
Just so.

And most fundamentally, the parents of children were not selected randomly from the population. Infants of parents of varying socioeconomic status and race might give children up for adoption, or have them taken into care, for very different reasons.
Quite true.

But:

We don't know whether maternal effects were involved - they are a "possibility."

We don't know whether the parents were unusually high or low for IQ - their IQs are "unknown."

We don't know what effect, if any, the (unspecified) mean age difference would have had.

We don't know whether it's true that parents give up kids for different reasons, only that they "might." And we don't know whether this could have any effect - we're just expected to assume that it could.

But Jensen brings up real, solid points which mitigate the results and interpretation of the German study:

The black fathers of the German kids were smarter than average. This isn't a possibility - it's what we know.

Heterosis probably boosted the IQ scores - this isn't just a guess; you can see heterosis showing up in Scarr & Weinberg's study, too.

And there were no fully black kids for comparison, just half-black children - there's no speculation about this, as they all had white mothers.

So while there's room for doubt, and probably good reason to do a better follow-up study, the mitigating points brought up to explain the Scarr & Weinberg study are generally... well... vaporous, while the mitigating points brought up against the German Study have some actual substance to them.


--Mark
 
  • #51


Sorry to say that, as reported in the link you posted Nachtwolf, the Minnesota and German studies only very weakly support Jensen's (and hitssquad's, and yours, and Apollo's, and Adam's?) assertion.

By far the biggest problem is the conflating of 'unknown' with 'random'; a second (but still large) problem is identifying the adopted children as 'black' or 'white'

{bold blue text is from http://psycprints.ecs.soton.ac.uk/archive/00000692/ [/color]}
Nachtwolf: To give a more specific analysis:
{the adoption study has several flaws[/color]}
Nachtwolf: Certainly. Scarr & Weinberg admit that no study is perfect.
A study with flaws is not unusual; a study which is accepted without a serious attempt to estimate the potential size of systematic errors is worthless.
{Maternal effects were not considered as a serious possibility for the lower IQ of blacks relative to whites.[/color]}
Nachtwolf: Maybe not.
Ignoring a leading alternative hypothesis is intellectual dishonesty (at least). Translation of Nachtwolf's comment?: I don't care what the alternative hypotheses are, I know I'm right, and won't countenance any dissenting interpretations.
{The IQ of parents of adopted children was unknown.[/color]}
Nachtwolf: Indeed.
Er, did you realize that this is, in fact, fatal to your case?
{The mean age of adopted infants also differed between treatment groups.[/color]}
Nachtwolf: Just so.
{And most fundamentally, the parents of children were not selected randomly from the population. Infants of parents of varying socioeconomic status and race might give children up for adoption, or have them taken into care, for very different reasons.[/color]}
Nachtwolf: Quite true.
IIRC, you, hitssquad or Jensen actually stated that this was quite important. Unless these differences are well accounted for, it's likely the study's results say little or nothing wrt your key assertions.
Nachtwolf: But:

We don't know whether maternal effects were involved - they are a "possibility."

We don't know whether the parents were unusually high or low for IQ - their IQs are "unknown."

We don't know what effect, if any, the (unspecified) mean age difference would have had.

We don't know whether it's true that parents give up kids for different reasons, only that they "might." And we don't know whether this could have any effect - we're just expected to assume that it could.
Hmm, and the Minnesota study is the landmark study which most clearly makes the hereditarian IQ case??

If Nachtwolf's comments are indicative of how the scientific method is applied in IQ studies, I can only say that there would clearly be prima facie grounds for ignoring the entire field as serious science. Fortunately, reading through the papers in the link I originally posted, I conclude that few of the professionals are so cavalier as Nachtwolf appears to be.
Nachtwolf: But Jensen brings up real, solid points which mitigate the results and interpretation of the German study:

The black fathers of the German kids were smarter than average. This isn't a possibility - it's what we know.
Those are confounding factors which need to be taken into account; they are not reasons to dismiss the German study out of hand (or, if they are, there are equally good reasons for dismissing the Minnesota study).
Nachtwolf: Heterosis probably boosted the IQ scores - this isn't just a guess; you can see heterosis showing up in Scarr & Weinberg's study, too.

And there were no fully black kids for comparison, just half-black children - there's no speculation about this, as they all had white mothers.
I couldn't believe this when I first read it, and I'm still find it hard to believe Nachtwolf was serious when he wrote it. Jensen himself cites studies which show that groups of 'blacks', geographically, have a 'white' ancestry which ranges from (IIRC) 4% to 40%; he also makes it very clear that within groups of people (such as 'Californian blacks') there is considerable variation in the degree of 'white' ancestry. Further, though he didn't dwell on this (I wonder why not?), the same thing can undoubtedly be said of 'whites' (even for the German mothers; for example, what is their 'Roma' ancestry?).

Yet, without at least some reliable data on the 'blackness' and 'whiteness' of the parents, any conclusions about the 'racial' hereditability of IQ are meaningless. And it's even worse when so much about the parents is 'unknown' (esp in the Minnesota study).
Nachtwolf: So while there's room for doubt, and probably good reason to do a better follow-up study, the mitigating points brought up to explain the Scarr & Weinberg study are generally... well... vaporous, while the mitigating points brought up against the German Study have some actual substance to them.
Translation: Nachtwolf doesn't really understand his own case, how hereditability works, why analysis of systematic errors and confounding factors is important, and so on.

Accuracy and attention to detail: 1
Natchwolf: 0
 
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  • #52
{Maternal effects were not considered as a serious possibility for the lower IQ of blacks relative to whites.}

Nereid, the Minnesota study was not about finding reasons why blacks have lower IQ than whites. It was about the degree in which IQ and a lot of other variables were inherited, based on on comparison studies of mono- and dizygotic twins raised together and apart. This was a perfectly sound research topic, as they had data available to do a much better study than had ever been done before, and Science published the results in a leading article. Are there possibly other factors? Surely, and let there be other studies to examine them.

The lack of data on the parents of the adopted children limits the scope of the study but does not invalidate the results that it found. If you will look at it honestly you will see that the attempts to characterize it as unsound by raising all sorts of other potential causes that it might have studied but didn't for are themselves flawed by a parti pris desire to hit it with any club avilable.
 
  • #53
Originally posted by selfAdjoint
{Maternal effects were not considered as a serious possibility for the lower IQ of blacks relative to whites.}

Nereid, the Minnesota study was not about finding reasons why blacks have lower IQ than whites. It was about the degree in which IQ and a lot of other variables were inherited, based on on comparison studies of mono- and dizygotic twins raised together and apart. This was a perfectly sound research topic, as they had data available to do a much better study than had ever been done before, and Science published the results in a leading article. Are there possibly other factors? Surely, and let there be other studies to examine them.

The lack of data on the parents of the adopted children limits the scope of the study but does not invalidate the results that it found. If you will look at it honestly you will see that the attempts to characterize it as unsound by raising all sorts of other potential causes that it might have studied but didn't for are themselves flawed by a parti pris desire to hit it with any club avilable.
Careful...again, correlation doesn't equal causation. Let's not get them confused, shall we?
 
  • #54
Context, as Russ is known to have said, is important

Originally posted by selfAdjoint
{Maternal effects were not considered as a serious possibility for the lower IQ of blacks relative to whites.}

Nereid, the Minnesota study was not about finding reasons why blacks have lower IQ than whites. It was about the degree in which IQ and a lot of other variables were inherited, based on on comparison studies of mono- and dizygotic twins raised together and apart. This was a perfectly sound research topic, as they had data available to do a much better study than had ever been done before, and Science published the results in a leading article. Are there possibly other factors? Surely, and let there be other studies to examine them.

The lack of data on the parents of the adopted children limits the scope of the study but does not invalidate the results that it found. If you will look at it honestly you will see that the attempts to characterize it as unsound by raising all sorts of other potential causes that it might have studied but didn't for are themselves flawed by a parti pris desire to hit it with any club available.
The context:

Nereid, quoting B. Raymond:
"... Jensen dismisses data from a racial admixture study in Germany which found no significant or consistent differences in IQ with race, because parental IQ was unknown, and because white and black fathers were not randomly sampled, two faults shared with the Minnesota adoption study. The absence of differences in the German study is also consistent with a maternal effects hypothesis, since the mothers were all white.[/color]"

and
"Jensen's "default hypothesis" is that differences in white and black IQ scores are made up of genetic and environmental effects and that environmental effects are often small relative to genetic effects (e.g. pp. 177-175, 475, 476, 489). These conclusions seem best supported by estimates of heritability [...] and from the Minnesota transracial adoption study. This adoption study has several flaws. Maternal effects were not considered as a serious possibility for the lower IQ of blacks relative to whites. The IQ of parents of adopted children was unknown. The mean age of adopted infants also differed between treatment groups. And most fundamentally, the parents of children were not selected randomly from the population. Infants of parents of varying socioeconomic status and race might give children up for adoption, or have them taken into care, for very different reasons.[/color]"

Nereid: "Would you [Nachtwolf] care to counterpose the Minnesota transracial adoption study with the German study?"

Nachtwolf gave a link to a webpage as an answer to this question; my response was based on this webpage's characterisation of the Minnesota study; Nachtwolf did not post a link to a paper published in Science.

So, the context is 'black/white' differences in IQ scores, the extent to which the Minnesota study supports Jensen's default hypothesis (Nachtwolf's assertion?) while the German study is irrelevant to the same assertion.
 
  • #55
So, the context is 'black/white' differences in IQ scores, the extent to which the Minnesota study supports Jensen's default hypothesis (Nachtwolf's assertion?) while the German study is irrelevant to the same assertion.

Sure. But then you pass from the fact that the Minnesota test doesn't support the conclusions from the German study to attacking the Minnesota study (or quoting somebody who does) because it wasn't designed to do that.
 
  • #56
A study with flaws is not unusual; a study which is accepted without a serious attempt to estimate the potential size of systematic errors is worthless.
This is an epistemological error. All study results have a margin for error, and the margin for error is never calculable, only, as you admit, estimable. This study was, quite clearly, better than the German study, in that it had fewer known problems. To call it "worthless" because it had a margin for error is juvenile.

Er, did you realize that this is, in fact, fatal to your case?
Did you not realize that, absent specific knowledge about the IQs of the mothers, we can assume that the law of averages would smooth out wrinkles and ensure that they were representative of their population? You are familiar with the law of averages? Right? God, it's so boring refuting your posts. Why do I perpetually feel like I'm taking an otherwise bright and intelligent person and having to explain the obvious? I can't believe I actually bothered replying to you. Especially when Zero's around:

correlation doesn't equal causation.
That has absolutely nothing to do with what selfAdjoint just said, Zero.

Let's not get them confused, shall we?
God forbid that you should become confused, hahaha!

If you will look at it honestly you will see that the attempts to characterize it as unsound by raising all sorts of other potential causes that it might have studied but didn't for are themselves flawed by a parti pris desire to hit it with any club avilable.
You know, the thing that's interesting to me, selfAdjoint, is that the Minnesota study was carried out by two people who both believed very firmly in the environmental hypothesis. I can't help but feel some sympathy for them, who had to suffer these attacks by people in their own camp, and at the same time be ridiculed by the Jensenists for their refusal to come around. I think that's why my sympathy stops, however - unlike Jensen, who started out as an environmentalist but then had the flexibility and honesty to change his position, trading his comfortable life for endless controversy and armed guards, Scarr and Weinberg clung to the security of familiar, safe beliefs. Ultimately, it's exactly this kind of cowardice which results in honest researchers like Jensen being forced to hire bodyguards. You're familiar with the Snyderman & Rothman poll, right? If the 45% who thought Jensen was right would all stand up and admit it, we might actually be able to have meaningful public dialogues on this subject and take all the mystery and vehemence out of it.


--Mark
 
  • #57
The Minnesota Twin study was largely funded by the Pioneer Fund.

Some of the Pioneer Fund's largest grants have gone to a well-known--and well-respected--study of twins at the University of Minnesota.

If you are not familiar with the Pioneer Fund, here is an exerpt from an article in the Phoenix New Times. It's a very long article, so I am showing just the Pioneer Fund info below to save reading through all of it.

------------
One of those testifying on behalf of lowering immigration levels was a man named Harry Hamilton Laughlin. An advocate of eugenics--a philosophy, then growing in popularity, which seeks to improve the human race through selective breeding--Laughlin cited Goddard's results and argued that the genetic "inadequacy" of eastern and southern Europeans would negatively affect "the germ plasm of the future American population."

Laughlin was one of several experts who helped convince Congress to severely clamp down on immigration in 1924. For the next 40 years--Beck's "Golden Era of Immigration"--immigrating to the U.S. from eastern Europe became very difficult; for Asians it became nearly impossible.

"For years, [Laughlin] successfully lobbied to maintain the restrictions, which eventually blocked an escape route for Jews fleeing the Nazis," Newsday reported in 1994. "In 1922, Laughlin wrote and lobbied for a law that forced the sterilization of tens of thousands of 'unfit' U.S. citizens, including the insane, the homeless and the blind."

Similar laws were later passed in Nazi Germany, where Laughlin was lauded. In 1936, the University of Heidelberg awarded Laughlin an honorary degree. Laughlin, in turn, asked the American Eugenics Society to offer Adolf Hitler an honorary membership.

The next year, five New York millionaires created a private foundation with an endowment of $5 million. One of those men was Wickliffe P. Draper, a textile tycoon who advocated sending American blacks to Africa.

The millionaires named their creation the Pioneer Fund and charged it with backing research in heredity, eugenics and "race betterment." Harry Laughlin became its first president.

He died four years later, however, and until the 1950s, the fund remained largely inactive. Partly, that may have been a result of the severe blow eugenics suffered as the truth about Nazi atrocities came to light. In 1950, the United Nations made its famous declaration in the wake of the Holocaust that "Mankind is one."

Eugenicists and researchers in hereditary intelligence were all but driven underground

The Pioneer Fund persevered, however, and became increasingly active through the 1950s. It was the fund's opposition to the 1954 Brown v. Board of Education Supreme Court decision to integrate public schools which attracted its current president, New York lawyer Harry F. Weyher, who assumed the job in 1958.

Since then, the Pioneer Fund has doled out money to people such as Roger Pearson, a British ex-patriate living in Georgia who, in 1958, founded the Northern League to promote "the interests, friendship and solidarity of all Teutonic nations."

"Early recruits," reports the London-based Independent, "included Hans Gunther, who was awarded a Goethe medal in 1941 for his work on Nordic racial philosophy, Ernest Sevier Cox, an American leader of the Ku Klux Klan, and Dr. Wilhelm Kusserow, a former SS Untersturmfuhrer."

Between 1981 and 1991 alone (payments continued at least through 1994), Pearson received $568,000 from the Pioneer Fund to publish Mankind Quarterly, a publication dedicated to "race science."

In the 1970s, reports the Independent, Mankind Quarterly's editorial advisers included Otmar, Baron Von Verscheur, who had served as director of the genetics and eugenics program at the Kaiser Wilhelm Institute during World War II. While at the institute, the baron recommended one of his students, Joseph Mengele, for a post as doctor at Auschwitz.

http://www.phoenixnewtimes.com/issues/1997-12-25/feature.html/1/index.html

<edit to add this is not about the Minnesota Transracial Study performed by Scarr after the first twin study>
 
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  • #58
Oh my God, you've found them out, Evo. And here we all thought that Scarr & Weinberg were actually liberals and bioegaletarians, based on the way they interpreted their own results as being, you know, supportive of the environmentalist position, but now we know they were really just a - a pack of Nazis! Oh my God, the Nazis, they're everywhere! It's a giant Nazi conspiracy funded by Pioneer, aaaaah!


--Mark
 
  • #59
Originally posted by Nachtwolf
Oh my God, you've found them out, Evo. And here we all thought that Scarr & Weinberg were actually liberals and bioegaletarians, based on the way they interpreted their own results as being, you know, supportive of the environmentalist position, but now we know they were really just a - a pack of Nazis! Oh my God, the Nazis, they're everywhere! It's a giant Nazi conspiracy funded by Pioneer, aaaaah!


--Mark
You make it so easy. And you don't even realize it, which makes it even funnier.

I was thinking today, wouldn't it be sad if Nachtwolf stopped posting, we wouldn't have anyone to toy with anymore. You do amuse us.
 
  • #60
I'm sorry - amidst all the smilies and irrelevant trivia involving Pioneer, I must have lost track of your point.

--Mark
 

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