Questions on _g_ and intelligence

[Mandrake]

PROLOG

I joined this group after reading through some of the dEarth's and finding that there were several people posting who were well informed and up to date on the subject of human intelligence. This is an attraction, since it is an exception to the general rule that people in discussion forums bring opinions and nothing else. I have been confronted several times by Evo with comments that were not informative, but which were apparently designed to silence me. When I reviewed her prior comments to other participants, I found that she was combative with them as well. Some of her replies to Moonbear, BV and bobf were amazingly confrontational without containing any information, logic, or analysis. I accept Evo's claims that she really knows about the things she dismisses, but I would like to ask her to tell us about those items without dismissing them, without giving just a link to something that may or may not be helpful, and without ducking the questions. I am sure she will eagerly answer questions, since she previously wrote: "Yes, BV doesn't answer to direct questions." I am sure that Evo will answer to direct questions.

Let me add that one contributor to these discussions (screen name "hitsquad") is well informed and has posted comments that are identical to what I would have written about the same issues. This person has addressed the questions pertaining to intelligence with facts that are scientifically valid and known to those who have studied the subject in depth.

QUESTIONS FOR EVO

Evo wrote:

Mandrake, for every argument you have made I have already posted (in previous threads) an argument that counters it. It would be foolish to restart the endless postings, it gets nowhere.

After looking at Evo's prior comments, I was not able to find that the above statement is true. In fact, I found nothing to suggest that her prior comments addressed some of my points at all. My questions pertain to the items Evo sought to dismiss by telling me that she has previously countered each. I have not found any such counter messages. I am also familiar enough with these topics to know that the information I presented is supported by a large body of mainstream psychometric literature and by the most recognized psychometricians throughout the world. So, I will repeat the items that Evo claims she has already countered and ask her for a logical and factual explanation as to how she countered the items.

1 - Intelligence is best represented by _g_.
Do you dispute this? If so, please state your case. I am using "intelligence" to mean the cognitive function that pertains to rate of learning, problem solving, and prediction of success in intellectually demanding academic subjects and careers.

2 - Virtually all of the external validity of IQ tests comes from their _g_ loading.
Do you agree? If not, state what parts of IQ tests contribute more to their external validity and explain how you arrived at your conclusion.

3 - What we know about _g_ is that it correlates strongly with various physiological conditions: nerve conduction velocity, pH, brain volume (and more specifically we now can see that particular areas of the brain are the actors and that their volumes correlate strongly with _g_), myelination, and information intake speed.
Do you wish to dispute these well established facts? Please tell me about each of them, since each is important to intelligence and to the variances in intelligence between population groups. People can and do measure these parameters with considerable accuracy.

4 - These factors influence working memory which is now known (seen the most recent issue of the journal Intelligence) is predicted almost perfectly by _g_.
First, I want to know if you have REALLY refuted this item, as you claimed. Did you? If so, have you read the last issue of Intelligence? I get the impression that you are unfamiliar with any of the material from this peer reviewed source, so I find it very difficult to believe that you actually know about the recent study that showed the near perfect prediction of working memory from _g_ measures. Please correct me if I am wrong about this. Then tell me how you refuted this very recent finding.

5 - All of the physiological measurements are seen between the population groups that are known to differ in mean IQ scores.
How did you refute this? What is your source of information? I would like to suggest that you read all of Jensen's The _g_ Factor as a good source of information.

6 - It is possible to measure _g_ by elementary cognitive tests (which are based on response time chronometrics), with a result that correlates as well with standard IQ tests as those tests correlate with each other.
This is a simple fact. I am absolutely amazed that you refuted it. Please tell me how you disputed such a massive amount of psychometric study. As you hopefully know, this has been an area of intense psychometric research for many years and continues to be so. To further your understanding of this topic, I would like to suggest that you read all of Chris Brand's book The _g_ Factor: General Intelligence and Its Implications. Please tell me how you countered this entire field of study.

7 - It is likewise possible to determine _g_ by electroencephalography using several different techniques and with similar accuracy.
And how did you refute this? Are you familiar with the techniques used to determine _g_ from EEG amplitude measurements? Aside from those, what do you think about the string length correlation?

8 - Both of these techniques are essentially passive, not subject to practice effects, and are totally blind to all social factors.
So, you REALLY refuted this one? I find it very hard to believe that anyone would argue that electroencephalography, RT, or IT measurements are influenced by social factors. Where did you find studies that show otherwise?

 

[Nereid]

Mandrake, since you chose to post on an open forum, and not ask Evo via PM, I have taken the liberty of reading this, and have some questions and comments of my own; I do hope you will address them.

PROLOGI joined this group after reading through some of the dEarth's and finding that there were several people posting who were well informed and up to date on the subject of human intelligence. This is an attraction, since it is an exception to the general rule that people in discussion forums bring opinions and nothing else. I have been confronted several times by Evo with comments that were not informative, but which were apparently designed to silence me. When I reviewed her prior comments to other participants, I found that she was combative with them as well. Some of her replies to Moonbear, BV and bobf were amazingly confrontational without containing any information, logic, or analysis. I accept Evo's claims that she really knows about the things she dismisses, but I would like to ask her to tell us about those items without dismissing them, without giving just a link to something that may or may not be helpful, and without ducking the questions. I am sure she will eagerly answer questions, since she previously wrote: "Yes, BV doesn't answer to direct questions." I am sure that Evo will answer to direct questions.

Let me add that one contributor to these discussions (screen name "hitsquad") is well informed and has posted comments that are identical to what I would have written about the same issues. This person has addressed the questions pertaining to intelligence with facts that are scientifically valid and known to those who have studied the subject in depth.

QUESTIONS FOR EVO

Evo wrote:
After looking at Evo's prior comments, I was not able to find that the above statement is true. In fact, I found nothing to suggest that her prior comments addressed some of my points at all. My questions pertain to the items Evo sought to dismiss by telling me that she has previously countered each. I have not found any such counter messages. I am also familiar enough with these topics to know that the information I presented is supported by a large body of mainstream psychometric literature and by the most recognized psychometricians throughout the world. So, I will repeat the items that Evo claims she has already countered and ask her for a logical and factual explanation as to how she countered the items.

1 - Intelligence is best represented by _g_.
Do you dispute this? If so, please state your case. I am using "intelligence" to mean the cognitive function that pertains to rate of learning, problem solving, and prediction of success in intellectually demanding academic subjects and careers.

I am aware that there has been extensive study of the relationship between 'intelligence' and _g_ in the US, and possibly in Canada and the UK (e.g. Jensen); how extensive has the research been on the 'intelligence' and _g_ relationship in other parts of the world?

2 - Virtually all of the external validity of IQ tests comes from their _g_ loading.
Do you agree? If not, state what parts of IQ tests contribute more to their external validity and explain how you arrived at your conclusion.

same question as above.

3 - What we know about _g_ is that it correlates strongly with various physiological conditions: nerve conduction velocity, pH, brain volume (and more specifically we now can see that particular areas of the brain are the actors and that their volumes correlate strongly with _g_), myelination, and information intake speed. Do you wish to dispute these well established facts? Please tell me about each of them, since each is important to intelligence and to the variances in intelligence between population groups. People can and do measure these parameters with considerable accuracy.

This is quite new to me! Last time I looked, the research was quite equivocal - some studies had positive results, some negative, some mixed.

4 - These factors influence working memory which is now known (seen the most recent issue of the journal Intelligence) is predicted almost perfectly by _g_.
First, I want to know if you have REALLY refuted this item, as you claimed. Did you? If so, have you read the last issue of Intelligence? I get the impression that you are unfamiliar with any of the material from this peer reviewed source, so I find it very difficult to believe that you actually know about the recent study that showed the near perfect prediction of working memory from _g_ measures. Please correct me if I am wrong about this. Then tell me how you refuted this very recent finding.

5 - All of the physiological measurements are seen between the population groups that are known to differ in mean IQ scores.
How did you refute this? What is your source of information? I would like to suggest that you read all of Jensen's The _g_ Factor as a good source of information.

Would you please clarify this? IIRC, Jensen was quite explicit that his work had applicability only to the US.

6 - It is possible to measure _g_ by elementary cognitive tests (which are based on response time chronometrics), with a result that correlates as well with standard IQ tests as those tests correlate with each other.
This is a simple fact. I am absolutely amazed that you refuted it. Please tell me how you disputed such a massive amount of psychometric study. As you hopefully know, this has been an area of intense psychometric research for many years and continues to be so. To further your understanding of this topic, I would like to suggest that you read all of Chris Brand's book The _g_ Factor: General Intelligence and Its Implications. Please tell me how you countered this entire field of study.

7 - It is likewise possible to determine _g_ by electroencephalography using several different techniques and with similar accuracy.
And how did you refute this? Are you familiar with the techniques used to determine _g_ from EEG amplitude measurements? Aside from those, what do you think about the string length correlation?

This is also new to me - has this work been done only in the US too?

8 - Both of these techniques are essentially passive, not subject to practice effects, and are totally blind to all social factors.
So, you REALLY refuted this one? I find it very hard to believe that anyone would argue that electroencephalography, RT, or IT measurements are influenced by social factors. Where did you find studies that show otherwise?

IIRC, around the time of the publication of the bell curve, there was a great deal of press from critics, who included many actively working in the same field as Jensen, Brand, etc. Would you be so kind as to tell us, a) who these 'same field' critics were, b) whether they are still active in these fields, c) what these critics positions are re the 8 points above?

 

[Evo]

Mandrake, none of this has to do with your posts that I was referring to. I had not even read your post #36 yet, although I have also posted information on the heritability of g, if you've read my posts about it, you know that I agree on the heritability, but I do not agree that it is as high or singularly important as what you post.

Here are the posts I was referring to:

Why do you make the assumption that it was lack of intelligence and not lack of necessity?

I have previously addressed this. The clue is the mean IQ as measured in various Sub-Saharan African nations. I assume you are familiar with Lynn's book on this topic.

In the US, the Black mean IQ is below the white mean. The IQ difference between US Blacks and Whites of European descent is given by Jensen as 1.36 SD [P. 17 The _g_ Factor]

Occupation and income related to psychometric g
Helmuth Nyborg, Arthur R. Jensen
Intelligence 29 (2001) 45-55

Table 1
Percentage of Whites and Blacks within each interval (in percentiles for total sample) of g factor scores

Percentile of g factor scores
Group___10__20___30____40___50___60____70____80____90___100
White__5.9__6.4___9.1__11.4__7.2__12.___11.7___12.1___9.2__14.3
Black__33.9_18.7__19.3__12.3__4.6___3.8___3.6___1.8___1.8___0.2

The indicated percentiles represent the upper limit of each interval.

Intelligence and Social Policy: A Special Issue of the Multidisciplinary Journal INTELLIGENCE. Edited by Douglas K. Detterman. Jan/Feb 1997 (Vol 24, No.1).

The military, unlike the private sector, discriminates based on race right up front. They do not allow low intelligence recruits to enter the military. The lowest intelligence levels allowed are Army 85, Marines and Air Force 88, and the Navy 91! And what does this mean for affirmative action. Well, taking the army for example, over half of all blacks do not qualify with an average IQ of 85. All one has to ask is why is it all right for the Army to discriminate based on intelligence, but a business can't? Why the double standard? And using the same statistical data, the Navy is allowed to eliminate 65% of all blacks from consideration (that is, 65% fall below the 91 IQ cut off).
===

The Nyborg, Jensen paper I referenced shows that the Black and White racial regression lines for income versus intelligence cross at the 40th percentile. Above that point, Black income exceeds that of Whites. The authors note: "However, in the present study sample the overall average income of Bs is only 77% that of Ws, given that in the total study sample 84.2% of Bs are below the 40th percentile of g scores compared to 32.8% of Ws, and 67.2% of Ws are above the 40th percentile compared to 15.8% of Bs."

For ALL percentiles, the job status index for Blacks exceeds that for Whites (index plotted against _g_ percentiles) with the gap increasing linearly as intelligence increases.

These rather recent observations are consistent with similar observations reported in The Bell Curve.

I have repeated the scientific findings of the past 100 years, which have consistently shown that the mean IQs of various population groups are not identical. Is that racist? If you think so, I would like to suggest that you have no idea of what constitutes racism. For examples of real racism, please study the history of Japan and Germany at the time of WW2.

As for population groups, the highest mean is found among Ashkenazi Jews.
After that, in order of decreasing means, we have Asians, whites of European descent, Hispanics, US blacks, and Sub-Saharan Africans, to name some of the prominent groups. It has been over 75 years since Spearman's Hypothesis was recorded; since that time there has been much effort expended to disprove it, but the result has been to prove the hypothesis beyond doubt.

Anyone who believes that IQ tests are biased against blacks should take the time to read Jensen's Bias in Mental Testing. This massive book examines IQ tests in detail and shows under what circumstances they are biased and under what circumstances they are not. Standard IQ tests are not biased against blacks. It is well documented that those tests are slightly biased in favor of blacks, by virtue of their external validity. That is, blacks perform less well than other groups in colleges and jobs as compared to individuals in those other groups with identical IQ scores.

The findings of Bias in Mental Testing were rejected by liberals on the basis of their non-scientific "feelings" as to how the results should have turned out. As a result they demanded and got the National Academy of Sciences to review the findings. The result was that the National Academy of Sciences found that there was (as Jensen had meticulously reported) no bias in IQ tests that caused lower scores for blacks. [This information is widely reported. One source is P. 83 of Miele (2002) - Intelligence, Race, and Genetics: Conversations with Arthur R. Jensen]

As I said, I have previously countered these topics and do not wish to do it over and over. I do not have time to sort through hundreds of posts.

Here is one that I posted, just sort of addresses all of the above.

http://www.raceandhistory.com/historicalviews/ukwise.htm

 

[Mandrake]

Mandrake, since you chose to post on an open forum, and not ask Evo via PM, I have taken the liberty of reading this, and have some questions and comments of my own; I do hope you will address them.

Thank you for replying. I posted the thread so that all here could enter into discussions of the items in question. I will be happy to comment on your questions and observations. This may take me a while, so I will post the detailed replies in a separate message.

 

[Mandrake]

I do hope you will address them.

Okay, here goes:

I am aware that there has been extensive study of the relationship between 'intelligence' and _g_ in the US, and possibly in Canada and the UK (e.g. Jensen); how extensive has the research been on the 'intelligence' and _g_ relationship in other parts of the world?

Psychometrics is an international science. It has been advanced by scientists from many countries. As an illustration I will present a few examples below:
Eysenck -- Berlin (later London)
Spearman -- England
Stern -- Germany
Deary -- Scotland (will deliver the keynote address at the next conference of the International Society of Intelligence Research {ISIR} -- in honor of the 100th adversary of Spearman's discovery of _g_)
Lynn -- England
Plomin -- England
Burt -- England
J. Hunt -- England
Rushton -- Canada
Vernon -- Canada
Brand -- England
Binet -- France
Galton -- England
Barrett -- New Zealand
Weiss -- Germany (formerly East Germany)
Mary Smith -- Australia (not well known, but referenced by Jensen for her work in eye blink response)

Those are only a few of the well known scientists. If you scan through the papers in Intelligence you will find sources from many countries. For example, I have V32 #3 open right now; it contains contributions from London, Ireland, Spain, United States, Canada, Poland, and Scotland. That is only one issue!

2 - Virtually all of the external validity of IQ tests comes from their _g_ loading.
same question as above.

Same answer. The literature for this field is international. The external validity of IQ tests is basic to the field of study and has been reported internationally as it has been studied for various specific applications. Anyone reading the stream of papers over the years will notice that there is a lot of material from the US, but it is far from the only source.

3 - What we know about _g_ is that it correlates strongly with various physiological conditions: nerve conduction velocity, pH, brain volume (and more specifically we now can see that particular areas of the brain are the actors and that their volumes correlate strongly with _g_), myelination, and information intake speed.

This is quite new to me! Last time I looked, the research was quite equivocal - some studies had positive results, some negative, some mixed.

I can only suggest that you keep looking. Have you read Jensen, A. R. (1998). The g factor: The science of mental ability? It is one of the best references available for broad coverage of the topic of psychometrics. Of these, the brain volume subject has received particularly prolonged study. The development of fMIR technology has enabled researchers to identify and measure the volumes of specific parts of the brain and to correlate them to _g_ (even group factors show up as specific locations). The research was done by Richard Haier and was presented at the 2003 ISIR conference. This is cutting edge material.

Myelination is central to the neural noise model developed by Edward Miller and remains robust a decade after he first wrote about it. Nerve conduction velocity seems to explain the variance in RT measured by many researchers and is presumed to be related to the volatile nature of working memory. RT measurements show that the variance in RT correlates independently to IQ. This cannot be explained by NCV, but does fit Miller's explanation based on neural noise. It appears that both factors are operating and are independent.

Information intake speed has continued to be reported regularly in Intelligence. Much of the present day research is focused on inspection time, instead of response time, but response time remains central to the understanding of chronometrics. The quantity of papers on this subject is so large that there is no one researcher to identify as the most important.

5 - All of the physiological measurements are seen between the population groups that are known to differ in mean IQ scores.

Would you please clarify this? IIRC, Jensen was quite explicit that his work had applicability only to the US.

The US has multiple population groups, with known IQ differences. For example, there are Ashkenazi Jews, Whites of European ancestry, American Indians, Hispanics, and Blacks. The physiological differences in question have been measured by many different researchers. The point of my comment is that these differences appear as group differences and correlate with _g_ independently of the group identity. For example, that means that the mean brain volume differences between US blacks and US whites are as expected, given the differences in mean IQs for these two groups. Chronometric measurements similarly vary between groups in proportion to the observed differences in _g_ between the groups.

7 - It is likewise possible to determine _g_ by electroencephalography using several different techniques and with similar accuracy.

This is also new to me - has this work been done only in the US too?

Some of the work was done by Paul Barrett of New Zealand. The strongest correlations for neural adaptability (NA) were found by E. W. P. Schafer. I don't know where his laboratory is located. His NA index correlates at about +.82 with IQ, which is better than many standard IQ tests correlate with each other and equal to the best test to test correlations.

8 - Both of these techniques are essentially passive, not subject to practice effects, and are totally blind to all social factors.
So, you REALLY refuted this one? I find it very hard to believe that anyone would argue that electroencephalography, RT, or IT measurements are influenced by social factors. Where did you find studies that show otherwise?

IIRC, around the time of the publication of the bell curve, there was a great deal of press from critics, who included many actively working in the same field as Jensen, Brand, etc. Would you be so kind as to tell us, a) who these 'same field' critics were, b) whether they are still active in these fields, c) what these critics positions are re the 8 points above?

I am confused by your question. What is your reference to "same field" about? I didn't mention it in item 8. Was your question related to another point? The critics of The Bell Curve were overwhelmingly journalists who had no prior knowledge of the topic, even though Seligman's book (A Question of Intelligence) had been published about two years earlier and covered most of the same material. Besides that, anyone reading the scientific literature knew that the subjects discussed in The Bell Curve were old hat and some were known 75 or more years ago.

There were a handful of people who claimed credentials who also were critical of The Bell Curve. Of these, some were totally out of their field (Gould, for example) and some were simply the usual outliers that are found in any scientific field. They either didn't "get it" or they found that there was a real market for selling their opposition to people who wanted to hear anti-science ranting. Gardner is one of those. When The Bell Curve came out, I immediately bought it and read every word of it. I was amazed to see that it contained very little that was not already published (that "little" was the analysis of the National Longitudinal Study of Youth data set). Shortly, the ignorant press began to attack The Bell Curve and this infuriated Linda Gottfredson. She is incapable of sitting still when someone is publishing scientifically corrupt material (recently she completely dissected and destroyed Sternberg's Triarchic theory). She wrote the letter to the Wall Street Journal that someone here posted in another thread. She intentionally wrote it as an understatement because she wanted to get it signed and printed without delay. It appeared with the 52 signatures you have seen in the other thread. The simple fact is that no credible psychometricians object to the salient points covered in The Bell Curve. Murray has commented that the discussion that was hot after the book came out does not exist today because it is understood.

 

[BlackVision]

"Yes, BV doesn't answer to direct questions."

LOL. Now there is a joke if I ever saw one. I always directly answer questions. Evo on the other hand is the type that likes to play dodgeball. You should of seen the way she acted with my simple question "Does one's ability to be in higher SES improve with higher intelligence?" I asked her this 20 times, never got an answer.

 

[BlackVision]

As I said, I have previously countered these topics

You have never done such a thing. Although I'm sure you wish you had.

 

[NoahAfrican]

Please, can someone tell me whether or not we have reached the end of science in regards to the brain and the total cause and effects of human actions, performance and behavior? Has it been true in history that what was once state of the science understanding was later refuted as humans gained more knowledge of the phenomenon being hypothesized about?

It is interesting why Mandrak accepts such hypothesis in light of the fact that we have not reached the end of knowledge in regard to how the brain works. At base, these hypothesis are merely deduced or assumed from what humans have learned about the workings of the brain. Furthermore, given that there exist counter hypothesis, by equally accredited people in the field, how does people like Mandrak determine who to believe, when he has not the ability to do the research for himself?

Again, there is an obvious bias in what Mandrak chooses to believe, because he simply dismisses the counter hypothesis without elaborating on what discredit’s their authors. It is tantamount to the people who choose to watch FOX (Faux) news, instead of CNN or PBS news. They already have a preconceived notion of what they see as the truth, which happens to be represented by a conservative ideology, thus they gravity towards the conservative conclusion with they already hold, while attempting to discredit the other ideologies conclusions and opinions.

Again, what one believes without the ability to independently observe or reproduce is a choice based upon preexisting notions or beliefs.

 

[Evo]

You have never done such a thing. Although I'm sure you wish you had.

Yes, I posted counter opinions.

BV, you've not answered many direct questions.

 

[BlackVision]

BV, you've not answered many direct questions.

I think you mean you. Like how you ignored my question once again.

I always answer your questions which apparently you always shrug off because it's not something you want to hear.

 

[Moonbear]

When I reviewed her prior comments to other participants, I found that she was combative with them as well. Some of her replies to Moonbear, BV and bobf were amazingly confrontational without containing any information, logic, or analysis.

Evo's replies to me were confrontational? I've never gotten that impression. Perhaps it's all a matter of perspective?

I have some more comments regarding the substance of one of your other replies here...the stuff on fMRI. But, it's nearly 1:30 AM and I only got home from the lab about a half hour ago (just online while winding down before bed), so I'm not likely to provide a coherent argument on something that requires thinking right now. Besides, I had to go look up some new stuff and I'm too tired to absorb it all just yet. You forced me to catch up on recent findings with MRI, which is good. Though, I think some of what you wrote isn't completely accurate with regard to measuring volumes of parts of the brain, but that's the part I'm too tired to answer thoroughly just yet. I want to check a little more literature before I respond in case there is a new method that I'm not yet aware of...unless you already know if that study you mentioned presented at a conference is specifically looking at white matter volumes (I spotted an article tonight addressing white matter in developmental delay, so that might be related)?

And, will somebody please define "g" for me? I've seen a lot of quotes around here referring to some book by Jensen throwing around the term "g", but I really don't have a full grasp of what this is, and from the quotes I've seen, I'm not really enthusiastic about going and getting a copy of the book to find out.

 

[hitssquad]

What is g

will somebody please define "g" for me?

g is the source of broadest common variance in any given matrix of mental ability tests. Factor-loadings (including g-loadings) of mental tests are determined by factor analyzing the results of tests adminstered to multiple subjects. (In terms of the most widely used IQ tests, the vocabulary subtests tend to be revealed by factor analysis as having the highest g-loadings of any subtest.)

Since g is the most-general factor of mental-ability tests, it is the factor that is most predictive of general outcomes. Relatively narrow outcomes tend to be better predicted by narrower ability factors such as those that have been borrowed by Howard Gardner to form his list of "multiple intelligences."

I've seen a lot of quotes around here referring to some book by Jensen throwing around the term "g", but I really don't have a full grasp of what this is, and from the quotes I've seen, I'm not really enthusiastic about going and getting a copy of the book to find out.

It is called The g Factor (1998), and it is co-published online by the electronic library Questia ($120 annual subscription). Arthur Jensen is the world's greatest living authority on the g factor. Author of more than 400 peer-reviewed papers, he is one of the most-frequently cited scientists of all time, and all of his most important books (and his 1969 Harvard Educational Review article "How Much Can We Boost IQ and Scholastic Achievement?") are listed as citation classics by the Institute for Scientific Information (ISI). He earned his post-doctorate under Hans Eysenck at the University of London and rose to the unusually-high rank of supergrade professor while teaching Educational Psychology at UC Berkeley.

 

[Evo]

Evo's replies to me were confrontational? I've never gotten that impression. Perhaps it's all a matter of perspective?

Mandrake's a bit confused on some things.

 

[Mandrake]

Evo's replies to me were confrontational? I've never gotten that impression. Perhaps it's all a matter of perspective?

No, I picked up your name from the remainder of a post in which Evo was attacking other people, but not you. I apologize for including your name on the list.

 

[Mandrake]

Originally Posted by Evo
BV, you've not answered many direct questions.

I think you mean you. Like how you ignored my question once again.

I always answer your questions which apparently you always shrug off because it's not something you want to hear.

I pointed out in another thread that Evo also ducked the simple questions I posed. For example, I asked her if she had read The Bell Curve. I asked because she was critical and dismissive of it. You would think that, if she had read the book, she would recall doing so and that if she had not, she might recall that as well. She just ducked.

 

[Nereid]

Thanks Mandrake.

Some more equiries (I hope you don't mind)

Psychometrics is an international science. It has been advanced by scientists from many countries. As an illustration I will present a few examples below:
Eysenck -- Berlin (later London)
Spearman -- England
Stern -- Germany
Deary -- Scotland (will deliver the keynote address at the next conference of the International Society of Intelligence Research {ISIR} -- in honor of the 100th adversary of Spearman's discovery of _g_)
Lynn -- England
Plomin -- England
Burt -- England
J. Hunt -- England
Rushton -- Canada
Vernon -- Canada
Brand -- England
Binet -- France
Galton -- England
Barrett -- New Zealand
Weiss -- Germany (formerly East Germany)
Mary Smith -- Australia (not well known, but referenced by Jensen for her work in eye blink response)

Many of these names I don't recognise, but aren't Eysenck, Spearman, Burt, Binet, and Dalton all long since gone? Perhaps I simply don't understand 'psychometrics' - I had the impression it would be a very new field, something that really only began after objective study of the brain could start. How does it relate to other branches of neuroscience?

Same answer. The literature for this field is international. The external validity of IQ tests is basic to the field of study and has been reported internationally as it has been studied for various specific applications. Anyone reading the stream of papers over the years will notice that there is a lot of material from the US, but it is far from the only source.

Roughly speaking, what proportion of the papers are from scientists from economies of the developing world?

I can only suggest that you keep looking. Have you read Jensen, A. R. (1998). The g factor: The science of mental ability? It is one of the best references available for broad coverage of the topic of psychometrics. Of these, the brain volume subject has received particularly prolonged study. The development of fMIR technology has enabled researchers to identify and measure the volumes of specific parts of the brain and to correlate them to _g_ (even group factors show up as specific locations). The research was done by Richard Haier and was presented at the 2003 ISIR conference. This is cutting edge material.

Myelination is central to the neural noise model developed by Edward Miller and remains robust a decade after he first wrote about it. Nerve conduction velocity seems to explain the variance in RT measured by many researchers and is presumed to be related to the volatile nature of working memory. RT measurements show that the variance in RT correlates independently to IQ. This cannot be explained by NCV, but does fit Miller's explanation based on neural noise. It appears that both factors are operating and are independent.

Information intake speed has continued to be reported regularly in Intelligence. Much of the present day research is focused on inspection time, instead of response time, but response time remains central to the understanding of chronometrics. The quantity of papers on this subject is so large that there is no one researcher to identify as the most important.

I see Moonbear has noticed this; I'll dig up the references I remember reading which discussed the limitations of this research.

In the meantime, can you point me to a paper describing the commonly accepted experimental protocols? I'm particularly interested in subject selection and the extent to which double-blind protocols are employed.

The US has multiple population groups, with known IQ differences. For example, there are Ashkenazi Jews, Whites of European ancestry, American Indians, Hispanics, and Blacks. The physiological differences in question have been measured by many different researchers. The point of my comment is that these differences appear as group differences and correlate with _g_ independently of the group identity. For example, that means that the mean brain volume differences between US blacks and US whites are as expected, given the differences in mean IQs for these two groups. Chronometric measurements similarly vary between groups in proportion to the observed differences in _g_ between the groups.

Hmm. I'm still interested in knowing whether Jensen (and others) have been clear that their work has validity only in the geographical region in which it was conducted, or whether it can be used globally (and if so, why).

I am confused by your question. What is your reference to "same field" about? I didn't mention it in item 8. Was your question related to another point? The critics of The Bell Curve were overwhelmingly journalists who had no prior knowledge of the topic, even though Seligman's book (A Question of Intelligence) had been published about two years earlier and covered most of the same material. Besides that, anyone reading the scientific literature knew that the subjects discussed in The Bell Curve were old hat and some were known 75 or more years ago.

There were a handful of people who claimed credentials who also were critical of The Bell Curve. Of these, some were totally out of their field (Gould, for example) and some were simply the usual outliers that are found in any scientific field. They either didn't "get it" or they found that there was a real market for selling their opposition to people who wanted to hear anti-science ranting. Gardner is one of those. When The Bell Curve came out, I immediately bought it and read every word of it. I was amazed to see that it contained very little that was not already published (that "little" was the analysis of the National Longitudinal Study of Youth data set). Shortly, the ignorant press began to attack The Bell Curve and this infuriated Linda Gottfredson. She is incapable of sitting still when someone is publishing scientifically corrupt material (recently she completely dissected and destroyed Sternberg's Triarchic theory). She wrote the letter to the Wall Street Journal that someone here posted in another thread. She intentionally wrote it as an understatement because she wanted to get it signed and printed without delay. It appeared with the 52 signatures you have seen in the other thread. The simple fact is that no credible psychometricians object to the salient points covered in The Bell Curve. Murray has commented that the discussion that was hot after the book came out does not exist today because it is understood.

Sorry that I wasn't clear.

Let me give you an analogy first (like all analogies, it should not be extended beyond the scope for which I intend it): in astrophysics/cosmology literature you will see reference to 'dark energy' and to 'dark matter'. In the 'concordance model', the observations which point to the existence of both dark energy and dark matter are well accounted for (there are formal statistical measures of the goodness of fit). If one wanted to, one could probably prepare a statement on cosmology like the WSJ one (1994? 1995?) signed by approx the same number of active astronomers, astrophysicists, etc. However, there would be quite a few who wouldn't sign such a statement, and not just because they would feel such things are pointless (even though they may be staunch advocates of the concordance model). Such folk would include those who felt that the observational data was not good enough to conclude 'there exists dark matter or (especially) dark energy'; there would be those who have no trouble with the data pointing to something like DM or DE, but who view the concordance model as flawed or suspect for entirely other reasons; and so on.

So my question is two-fold:
1) are there serious critics of psychometrics? If so, what are their views - what are the bases of their critiques?
2) among those who are active in the field of psychometrics, what divergence of opinion is there? For example, how widely accepted are the conclusions of those who've done fMRI work?

Finally, if I have understood you correctly, it is now possible to determine the IQ of a person (or their g) purely from neurophysiology tests such as fMRI (with the appropriate double blind protocols of course) - yes? no? something else??

 

[Evo]

I pointed out in another thread that Evo also ducked the simple questions I posed. For example, I asked her if she had read The Bell Curve. I asked because she was critical and dismissive of it. You would think that, if she had read the book, she would recall doing so and that if she had not, she might recall that as well. She just ducked.

As I have pointed out in other threads, Mandrake, you have made a large number of false accusations and one outright lie. I suggest you stop.

Here is a good overview of the many posts on the Bell Curve and the people involved that I have been posting for some time. This kind of evidence cannot be dismissed.

The science behind The Bell Curve has been denounced by both the American Psychological Association and the Human Genome Project

"The scientific basis of The Bell Curve is fraudulent." (1)

With those words, the American Psychological Association denounced The Bell Curve, the controversial book that claims that blacks generally have IQs 15 points lower than whites. The authors assert that because IQ is mostly genetic and unchangeable, programs promoting equality (affirmative action, welfare, Head Start, etc.) are a waste of money. For those unfamiliar with the American Psychological Association, it is the largest scientific and professional organization representing psychology in the United States, and includes over 142,000 members.

http://www.huppi.com/kangaroo/L-bellcurvescience.htm

 

[hitssquad]

Psychometrics has been around for awhile

Perhaps I simply don't understand 'psychometrics'

Psychometrics is the use of scientific instruments to gather quantitative psychological data. An IQ test would be an example of a psychometric instrument — despite its reliance on voluntary responses from test subjects. Therefore, psychometrics does not merely refer to the use of instruments — such as the more-recently-invented evoked-potentials tests — that make use of involuntary resonses from test subjects.


M-W Unabridged definition of psychometrics:

Etymology: International Scientific Vocabulary
1 : relating to the measurement of mental or subjective data
2 : relating to or being a mental test or psychological method whose results are expressed quantitatively rather than qualitatively

 

[Mandrake]

Thanks Mandrake.

Some more equiries (I hope you don't mind)Many of these names I don't recognise, but aren't Eysenck, Spearman, Burt, Binet, and Dalton all long since gone?

Dalton was not on the list. The other four are dead. Eysenck died in October 1997, which doesn't seem that long ago to me. I gave you a list of mostly important people who are from other countries over the time period that applies to this field of science (roughly 100 years).

Perhaps I simply don't understand 'psychometrics' - I had the impression it would be a very new field, something that really only began after objective study of the brain could start.

Psychometrics began with mental testing. Spearman developed factor analysis and discovered _g_ in 1904.

How does it relate to other branches of neuroscience?

Much of the research in psychometrics is now in the area of neuroscience and genetics. Psychometrics has become a much more laboratory field in recent years.

Roughly speaking, what proportion of the papers are from scientists from economies of the developing world?

Roughly the same proportion that you find in such other scientific fields as super conductivity, nuclear fission, space exploration, brain surgery, metal matrix composites, etc.

In the meantime, can you point me to a paper describing the commonly accepted experimental protocols? I'm particularly interested in subject selection and the extent to which double-blind protocols are employed.

I suggest that you simply pick up and read a stack of the journal Intelligence. Each issue is filled with up to date research papers, and each explains its experimental procedures in the detail that you would expect for a peer reviewed source. The procedures used for measuring glucose uptake are quite different from the procedures used to measure working memory chunks.

Hmm. I'm still interested in knowing whether Jensen (and others) have been clear that their work has validity only in the geographical region in which it was conducted, or whether it can be used globally (and if so, why).Sorry that I wasn't clear.

Psychometrics is focused on mental performance, not geography. One large area of investigation has been the differences between population groups. I have never seen any indication that geography has been identified as a variable. There are studies in which Asian populations were tested in Asia and compared to first generation Asians who were born to the same population group, but in the US. The groups tested identically. As I recall, this was discussed in The Bell Curve, but it is always worth checking The _g_ Factor as well.

So my question is two-fold:
1) are there serious critics of psychometrics? If so, what are their views - what are the bases of their critiques?

Let me ask you to consider the question as applied to other fields. Are there serious critics of laser research? Of carbon composites? Of organic chemistry? Of space exploration? The answers are that when one gets down to individual issues, there will be some in which there are debates among informed people as to exactly what is happening. If the issue is something that has been resolved, the critics are most likely to be crackpots. At this point, the only people doubting the 100 year study of the variance in intelligence are crackpots. Likewise there are no informed people still arguing that population groups have identical mean IQs. Those issues were argued years ago and are now history.

2) among those who are active in the field of psychometrics, what divergence of opinion is there? For example, how widely accepted are the conclusions of those who've done fMRI work?

The answer is much the same. There is divergence on some issues and not on others. There are also a few people who are following their own lines by creating different models of how the brain works. Some of those will ultimately gain strength and some will evaporate. Ask yourself if there is universal agreement on all aspects of the Big Bang and you will get to a similar point.

Finally, if I have understood you correctly, it is now possible to determine the IQ of a person (or their g) purely from neurophysiology tests such as fMRI (with the appropriate double blind protocols of course) - yes? no? something else??

Not yet with fMIR. There are three ways to determine _g_: IQ tests, followed by an extraction of _g_; chronometric measurements; and electroencephalography measurements. With each of these there are various approaches that give reasonable results. There are no diverse tests that correlate perfectly.

 

[Nereid]

Psychometrics is the use of scientific instruments to gather quantitative psychological data. An IQ test would be an example of a psychometric instrument — despite its reliance on voluntary responses from test subjects. Therefore, psychometrics does not merely refer to the use of instruments — such as the more-recently-invented evoked-potentials tests — that make use of involuntary resonses from test subjects.


M-W Unabridged definition of psychometrics:

Etymology: International Scientific Vocabulary
1 : relating to the measurement of mental or subjective data
2 : relating to or being a mental test or psychological method whose results are expressed quantitatively rather than qualitatively

Thanks hitssquad.

What's the relationship between psychometrics and neuroscience then? When does psychometrics become something else (e.g. is it psychometrics when you study a person's eye movements while reading? how about a quantitative study of moods, of synesthesia, of sleep?

 

[Nereid]

Dalton was not on the list. The other four are dead. Eysenck died in October 1997, which doesn't seem that long ago to me. I gave you a list of mostly important people who are from other countries over the time period that applies to this field of science (roughly 100 years).

My typo, I meant Galton.

Psychometrics began with mental testing. Spearman developed factor analysis and discovered _g_ in 1904.

Much of the research in psychometrics is now in the area of neuroscience and genetics. Psychometrics has become a much more laboratory field in recent years.

What is its scope today? (I answered hitssquad before I saw your post; I'm quite curious as to the boundaries - e.g. is it psychometrics when my doctor uses an electronic stopwatch and ruler to measure my knee reflexes? since taste is subjective - and mental - and can be measured quantitatively I'm sure, is the study of taste a branch of psychometrics?)

I suggest that you simply pick up and read a stack of the journal Intelligence. Each issue is filled with up to date research papers, and each explains its experimental procedures in the detail that you would expect for a peer reviewed source. The procedures used for measuring glucose uptake are quite different from the procedures used to measure working memory chunks.

I'll see if my local library has a copy. Why is it called 'Intelligence'? From the definition, it would seem that intelligence would be a very small part of the field. I'd've thought that, since you're working with humans and their mental states, double blind protocols would be even more important in psychometrics than in studies of glucose uptake! Surely the psychometric equivalent of the placebo effect (or the 'white coat effect') would be huge

Psychometrics is focused on mental performance, not geography. One large area of investigation has been the differences between population groups. I have never seen any indication that geography has been identified as a variable. There are studies in which Asian populations were tested in Asia and compared to first generation Asians who were born to the same population group, but in the US. The groups tested identically.

Wow! That's truly staggering! After all, plenty of studies have shown that there are quite significant physiological differences between first generation migrants and their stay-at-home peers, esp the effects of diet (e.g. incidence of heart disease, the switching on - or off - of various enzyme reaction trigger genes, and much more). Too, IIRC, the effects of the childhood environment and pre-birth environments can be enormous - just look at the crack babies, and the well-known 'siblings' effects. The findings you just reported would seem, prima facie, to fly in the face of a vast amount of medical research.

Let me ask you to consider the question as applied to other fields. Are there serious critics of laser research? Of carbon composites? Of organic chemistry? Of space exploration? The answers are that when one gets down to individual issues, there will be some in which there are debates among informed people as to exactly what is happening. If the issue is something that has been resolved, the critics are most likely to be crackpots.

My comment was based on my assumption that it was a completely new field; in any new field, there is a period in which critics - rightly - question whether it is really a science. Look at astrobiology, for example.

At this point, the only people doubting the 100 year study of the variance in intelligence are crackpots. Likewise there are no informed people still arguing that population groups have identical mean IQs. Those issues were argued years ago and are now history.

Hmm, do you mean in the last ten years? The link which Evo posted has some pretty weighty pronouncements, e.g. "What is intelligence and can it be measured? These questions have fueled a continuing debate about whether intelligence is inherited, acquired, environmental, or a combination of these and other factors. In a field where so many issues are unresolved and so many questions unanswered, the confident tone that has characterized most of the debate on these topics is clearly out of place.[/color]" Of course, this is in reference to the bell curve, and was written in 1995. The 1996 letter to Science by the members of the HGP was also pretty damning - surely they're not crackpots?

The answer is much the same. There is divergence on some issues and not on others. There are also a few people who are following their own lines by creating different models of how the brain works. Some of those will ultimately gain strength and some will evaporate.

Is there now a biological theory of intelligence? Or are there competing theories?

Not yet with fMIR. There are three ways to determine _g_: IQ tests, followed by an extraction of _g_; chronometric measurements; and electroencephalography measurements. With each of these there are various approaches that give reasonable results. There are no diverse tests that correlate perfectly.

What are 'chronometric measurements'? What is the typical experimental error in _g_ from these? Ditto, for EEG measurements? How are the 'zero point' and scale of _g_ defined?

 

[Mandrake]

Nereid:

My typo, I meant Galton.

FWIW, one of the many very important books by Jensen, Bias in Mental Testing, was dedicated to Galton, Binet, and Spearman. Galton was so far ahead of his time that he had a strong interest in the inheritance of mental ability and wrote the book HEREDITARY GENIUS in 1896. Amazing!

Much of the research in psychometrics is now in the area of neuroscience and genetics. Psychometrics has become a much more laboratory field in recent years.

Before going further, I want to tell you that I appreciate your thoughtful and well stated comments and questions. It is a pleasure to converse with someone who is alert and not looking for a fight.

What is its scope today? (I answered hitssquad before I saw your post; I'm quite curious as to the boundaries - e.g. is it psychometrics when my doctor uses an electronic stopwatch and ruler to measure my knee reflexes? since taste is subjective - and mental - and can be measured quantitatively I'm sure, is the study of taste a branch of psychometrics?)

Psychometrics is about intelligence. It started with the development of mental tests, which became IQ tests. Psychometrics seeks to measure intelligence, to find its correlates, and to understand the root causes for the differences that are found. Essentially all of the work in psychometrics now falls in the category of "differential psychometrics." It is based on experimental and correlational methods.

It turns out that the variance in intelligence correlates with a very wide range of other things, such as the ability to differentiate pitch, myopia, the complexity of wave from from an EEG, brain response time to external stimuli, the energy consumption of the brain, pH, and some other factors, many of which are probably extrinsic, such as good looks, eye color, leg length, lung capacity, grip strength, etc.

I suggest that you simply pick up and read a stack of the journal Intelligence. Each issue is filled with up to date research papers, and each explains its experimental procedures in the detail that you would expect for a peer reviewed source. The procedures used for measuring glucose uptake are quite different from the procedures used to measure working memory chunks.

I'll see if my local library has a copy.

If not, a good university should have copies. I should add that INTELLIGENCE is THE journal of psychometrics. Although there are occasionally good papers presented in other places, the real focus of this scientific speciality is in the journal of the International Society for Intelligence Research. This small group includes almost every big name psychometrician alive and a few (me for example) who are groupies. ;-)

Why is it called 'Intelligence'? From the definition, it would seem that intelligence would be a very small part of the field.

"Intelligence" is the entire field. If it does not relate to intelligence, it is not part of psychometrics.

Psychometrics is focused on mental performance, not geography. One large area of investigation has been the differences between population groups. I have never seen any indication that geography has been identified as a variable. There are studies in which Asian populations were tested in Asia and compared to first generation Asians who were born to the same population group, but in the US. The groups tested identically.

Wow! That's truly staggering! After all, plenty of studies have shown that there are quite significant physiological differences between first generation migrants and their stay-at-home peers, esp the effects of diet (e.g. incidence of heart disease, the switching on - or off - of various enzyme reaction trigger genes, and much more).

Intelligence is determined by extrinsic and intrinsic genetic factors and by micro environmental factors. The micro environmental factors are real, but contribute relatively little to the total. These environmental effects are much more observable in childhood than later in life. It is also likely that some macro environmental effects can be seen in childhood, but these vanish by adulthood. You can also find IQ tests given to whites who live in Africa and you will see that those match their peer groups in Europe. For example, there are studies of intelligence in all of South Africa. The white population there is composed of Dutch and English stock. People don't suddenly become smarter or dumber because they move to another country.

More to the point, I have mentioned the very significant findings of the physiological correlations to intelligence. These hold not only within groups, but also between groups (including population groups). For example, brain volume has been studied by every means known (weighing brains from corpses, measuring head size, measuring skull volume, then by MRI mapping, etc.). The reason these studies have been continued is that the correlation between brain volume and intelligence is robust. It doesn't matter where the subjects lived, or what their race, the results correlate the same. Likewise the measurements of response time are indifferent to social or racial factors. Response time measurements, as applied to elementary cognitive tasks, are _g_ loaded in the range of about .2 to .3 or so, but their variances are additative. If you run an appropriate battery of tests, the sum of the variances produces an excellent measurement of _g_. This is basically the same as what happens in IQ test items. Each item is very lightly _g_ loaded, but a range of test items can be combined to yield a good final IQ score, from which _g_ can be extracted.

Too, IIRC, the effects of the childhood environment and pre-birth environments can be enormous - just look at the crack babies, and the well-known 'siblings' effects.

In science, one compares items from A that are equal to items from B, except for one variable. It would be inappropriate to compare crack babies from one country to normal babies from another. The big name psychometricians are very well educated scientists and have conducted their research quite carefully.

The findings you just reported would seem, prima facie, to fly in the face of a vast amount of medical research.

No. The idea is to allow only one variable at a time. I should add that some intelligence related papers have been written by physicians and most are full of errors that are traceable to the ignorance of psychometrics by the medical people.

My comment was based on my assumption that it was a completely new field; in any new field, there is a period in which critics - rightly - question whether it is really a science. Look at astrobiology, for example.

Psychometrics is not new, as you now know. It has benefitted from the same transformation that affected biology, namely the movement from limited laboratory research to the opposite.

At this point, the only people doubting the 100 year study of the variance in intelligence are crackpots. Likewise there are no informed people still arguing that population groups have identical mean IQs. Those issues were argued years ago and are now history.

 

[Mandrake]

Hmm, do you mean in the last ten years? The link which Evo posted has some pretty weighty pronouncements,

Do you mean her "kangaroo" link? I had seen that one before. It was put up by Steve Kangas, who says on his page that he is a student seeking a degree in Russian Studies. Is that a good source of scientific information? He identifies himself as an ultra-liberal and obviously has a very strong political agenda. If you look at his references, you will see that they include these scientific sources:
The San Francisco Chronicle
People For The American Way
USA Today
Boston Globe
The New York Times Magazine
Discovery Journal
The Nation,
Rolling Stone
Newsday
Newsweek.

e.g. "What is intelligence and can it be measured? These questions have fueled a continuing debate about whether intelligence is inherited, acquired, environmental, or a combination of these and other factors. In a field where so many issues are unresolved and so many questions unanswered, the confident tone that has characterized most of the debate on these topics is clearly out of place." Of course, this is in reference to the bell curve, and was written in 1995. The 1996 letter to Science by the members of the HGP was also pretty damning - surely they're not crackpots?

I didn't see the letter to Science. Can you provide me with the link? Do you have the names and job positions of the people who wrote the letter? APA is not a group of psychometricians, it is a group of psychologists, a few of whom may be psychometricians. When a letter goes out, it is not the joint finding of the entire membership nor is it the joint finding of those members who are actually qualified to make a judgement. If you want to read a real report of real scholars, who were polled and asked to respond only when they believed that they were qualified to answer, look up and read the Snyderman-Rothman report.

Psychological Reports, 1998, 82, 1346-1374. ©Psychological Reports 1998

Never cited by critics of The Bell Curve, however, are the findings of Snyderman and Rothman, who surveyed 1,020 experts in behavioral genetics and psychometrics in the 1980s. These findings, which were initially published in the American Psychologist (Snyderman & Rothman, 1987) and later in a book, The IQ Controversy: The Media and Public Policy (Snyderman & Rothman, 1988), were that 53% agreed that there is a consensus among psychologists and educators as to the kind of behaviors labeled as "intelligent" (p. 55); 60% agreed that IQ is an important determinant of socio-economic status (p. 66); 58% agreed that intelligence is a general ability rather than a multiplicity of separate faculties (p. 71); a majority of those responding agreed that there is a substantial within-group heritability for intelligence (p. 95); and a plurality agreed that part of the difference between black and white groups in average IQ is genetic in origin (p. 128) (Snyderman & Rothman, 1988).

My guess is that a repeat of this study would result in overwhelming agreements on the points listed. Most of these issues are dead, and yes, they died after publication of The Bell Curve. Again, the source of information is INTELLIGENCE and you will see that these items are now reported as if they were the gravitational constant, or the speed of light.

Jensen: "The fact that _g_ is more strongly genetic than most other psychological variables is not really controversial among empirical researchers in this field. It is highly controversial only in the popular media. Just try to find any real controversy among the experts who know the research on this issue." Miele (2002) - Intelligence, Race, and Genetics: Conversations with Arthur R. Jensen - P. 79. This is precisely what I have been saying. Notice that the folks here who cite newspapers and Russian Studies experts, versus those who cite real science. On that same page, Jensen discusses the Snyderman-Rothman study. He specifically mentions the APA. The reading is well worthwhile, but too long for me to copy.

Is there now a biological theory of intelligence? Or are there competing theories?

There are various models of how the brain processes information. Some of these can be diagramed and are shown in The _g_ Factor. There are also the sideline theories that have been advanced by Gardner and Sternberg. Neither holds water and neither stands up to quantative analysis. As I mentioned before Gottfredson wrote a very long paper in INTELLIGENCE replying to Sternberg's Triarchic Model. She examined every tiny thing he had claimed and totally destroyed each item. Both of these models are discussed in The _g_ Factor. Gardner's ideas are so far out that they are not taken seriously by more than a few devotees.

What are 'chronometric measurements'?

They include response time measurements to elementary cognitive tasks, such as pressing a button when a light goes on; and inspection time measurements, which are designed to measure the shortest time that a stimulus can be presented to an individual and still be recognized correctly. Brand has written a lot about IT and Jensen has written a lot about RT, but both areas have been widely reported by other researchers.

What is the typical experimental error in _g_ from these? Ditto, for EEG measurements?

I don't know from memory and don't have more time to devote to looking for the answer. The bottom line is that both measurements correlate strongly with _g_. RT has a somewhat stronger correlation, if a battery of diverse ECTs are used. IT is usually done in a single format, so there is not a battery of tests.

How are the 'zero point' and scale of _g_ defined?

_g_ is usually stated in terms of percentile, since the number is usually extracted from a conventional IQ test. IQ tests are not true ratio scales. Jensen has mentioned (many times) that a true ratio scale would be very valuable. After the last ISIR conference, Rushton said that he thought we were getting there. The tool he had in mind was chronometric measurement. I was irritated that I skipped the meeting because it was 3000 miles away, but this year I may spend the money and attend.

 

[NoahAfrican]

Mandrak...do you need an napkin or towel? Just wondering due to all the intellectual masturbating that you are doing. Give it a rest already ok...whites are the suprem God like being of the Earth and Universe...Ok...now...or are you on a campaing, like Hitler, to dominate the world with this Ayran philosoply.

 

[Evo]

Do you mean her "kangaroo" link? I had seen that one before. It was put up by Steve Kangas, who says on his page that he is a student seeking a degree in Russian Studies. Is that a good source of scientific information? He identifies himself as an ultra-liberal and obviously has a very strong political agenda. If you look at his references, you will see that they include these scientific sources:
The San Francisco Chronicle
People For The American Way
USA Today
Boston Globe
The New York Times Magazine
Discovery Journal
The Nation,
Rolling Stone
Newsday
Newsweek.

You intentionally omitted all of the references from the American Psychological Association and the Human Genome Project. How do you expect anyone to believe anything you say when you try to deceive them? If you have nothing to hide, why do you intentionally skew this list? Here are the sources Mandrake left out. I am disappointed in you Mandrake, I thought we could start over and debate this reasonably. Since you had to pick the other references from around them, you went to a deal of trouble to omit them.

3. Tori DeAngelis, "Psychologists question findings of Bell Curve," APA Monitor, American Psychological Association, October, 1995.

4. "Task Force Releases Report in Response to Bell Curve," American Psychological Association, Press Release, Fall 1995.

5. "APA Task Force Examines the Knowns and Unknowns of Intelligence," American Psychological Association, Press Release, September 15, 1995.

11. Lori B. Andrews, Dorothy Nelkin and endorsing members of the Human Genome Project, "The Bell Curve: A Statement," letter to the editor, Science, January 5, 1996.

Also, I borrowed that link from someone else here at PF. You don't even know who you are insulting, it isn't me.

I didn't see the letter to Science. Can you provide me with the link? Do you have the names and job positions of the people who wrote the letter?

http://www.people.virginia.edu/~rjh9u/bellcrv.html and a longer version of this statement was endorsed by the National society of Genetic Counselors.

APA is not a group of psychometricians, it is a group of psychologists, a few of whom may be psychometricians.

You seem to think quite highly of psychometricians, when I have sometimes heard "psychometrics" referred to as "voodoometrics", which I think isn't nice since there are good people and bad people and I disagree with labeling groups of people, it isn't right or completely true.

When a letter goes out, it is not the joint finding of the entire membership nor is it the joint finding of those members who are actually qualified to make a judgement.

Which is exactly why the APA formed an unbiased committee , including Thomas Bouchard. You can't get much more pro Bell Curve than that.

The members of the task force were chosen during a detailed process. Dr. Ulric Neisser, professor of psychology at Emory University, was appointed chair of the task force, several other members were nominated by one of several APA constituencies, and remaining members were selected in order to provide a range of expertise and perspectives. The task force included:

Ulric Neisser, Emory University (chair of the task force)
Gwyneth Boodoo, Educational Testing Service
Thomas J. Bouchard, Jr., University of Minnesota
A. Wade Boykin, Howard University
Nathan Brody, Wesleyan University
Stephen J. Ceci, Cornell University
Diane F. Halpern, California State University, San Bernadino
John C. Loehlin, University of Texas, Austin
Robert Perloff, University of Pittsburgh
Robert J. Sternberg, Yale University
Susana Urbina, University of North Florida

At this point, the only people doubting the 100 year study of the variance in intelligence are crackpots.

So, you claim the people listed above are crackpots? Nice.

Here is another link on The Bell Curve from the University of Wisconsin.

http://www.ssc.wisc.edu/irp/featured/bellcurv.htm

 

[Nereid]

Psychometrics is the use of scientific instruments to gather quantitative psychological data. An IQ test would be an example of a psychometric instrument — despite its reliance on voluntary responses from test subjects. Therefore, psychometrics does not merely refer to the use of instruments — such as the more-recently-invented evoked-potentials tests — that make use of involuntary resonses from test subjects.


M-W Unabridged definition of psychometrics:

Etymology: International Scientific Vocabulary
1 : relating to the measurement of mental or subjective data
2 : relating to or being a mental test or psychological method whose results are expressed quantitatively rather than qualitatively

Psychometrics is about intelligence. It started with the development of mental tests, which became IQ tests. Psychometrics seeks to measure intelligence, to find its correlates, and to understand the root causes for the differences that are found. Essentially all of the work in psychometrics now falls in the category of "differential psychometrics." It is based on experimental and correlational methods.

[...]

"Intelligence" is the entire field. If it does not relate to intelligence, it is not part of psychometrics.

That's quite a difference (of opinion?)! So I did some research of my own ... http://www.fordham.edu/aps/whatpsy.html I found the following: "Psychology is a diverse and exciting field. As pioneers in a relatively youthful science psychologists worldwide strive to improve every aspect of human life, from planning urban construction and zoning to human-computer interaction. Across all disciplines of psychology there is a common thread that unites all researchers and scientists in the field. This unifying discipline is psychometrics.[/color]" This helped me a lot; rather than just intelligence, the term 'psychometrics' seems to refer to psychology as a whole. This also puts the relationship with neuroscience and biology in general into perspective - the more 'fundamental' field of science is the newer neuroscience.

Do you mean her "kangaroo" link? I had seen that one before. It was put up by Steve Kangas, who says on his page that he is a student seeking a degree in Russian Studies. Is that a good source of scientific information? He identifies himself as an ultra-liberal and obviously has a very strong political agenda. If you look at his references, you will see that they include these scientific sources:

I decided to check the sources on the page for myself; I see that Evo has already posted some words about these (including a link to the Andrews and Nelkin 1996 Letter to Science). From these materials I gather that there is (or was) quite a deal of controversy among US psychologists about the book. To be sure I don't misunderstand, are Andrews and Nelkin 'crackpots'? What about members of the APA taskforce - are they crackpots too?

 

[hitssquad]

Geographical limitations to some of Jensen's conclusions

I'm still interested in knowing whether Jensen (and others) have been clear that their work has validity only in the geographical region in which it was conducted, or whether it can be used globally (and if so, why).

• We have seen in the foregoing chapters that many lines of psychometric evidence converge to the conclusion that, by and large, current standardized tests of general mental ability and scholastic achievement, as well as many vocational aptitude tests, are not biased with respect to any native-born, English-speaking minority groups in the United States. This generalization can be extended in the case of nonverbal tests to native-born non-English-speaking minority groups as well. These conclusions are confined to native-born subpopulations within the United States, not because of any evidence on immigrant groups or on populations outside the United States that is at odds with the present conclusions, but only because of the lack of relevant studies that would warrant any broader conclusions.

(Arthur Jensen. Bias in Mental Testing. 1980. Chapter 15: Uses and Abuses of Tests. p715.)

 

[Nereid]

Thanks hitssquad. I have a vague recollection that Jensen said something similar in a later work too.

To me, this Jensen statement is an indication that he takes science seriously; in particular, since there is no underpinning, widely accepted biological (or neurological) theory of psychology, extrapolations beyond the 'experimental subject universe' should be made only with extreme caution.

An example of how complex the relationship between behaviour, genetics, and brain function is reported recent findings on depression (a much stigmatised condition which may affect ~10% of us all).

 

[Mandrake]

That's quite a difference (of opinion?)!

I must be missing something. What difference do you see?

"Psychology is a diverse and exciting field. As pioneers in a relatively youthful science psychologists worldwide strive to improve every aspect of human life, from planning urban construction and zoning to human-computer interaction. Across all disciplines of psychology there is a common thread that unites all researchers and scientists in the field. This unifying discipline is psychometrics.[/color]"

Psychology is a broad field that contains many areas of specialization that have little or nothing to do with psychometrics. If a behavior or ability is dependent on intelligence (such as learning rate), it links to psychometrics. I expect you can obtain a list of Intelligence paper titles from Sciencedirect.com, but that may not be available to people who do not belong to ISIR. A list of paper titles will quickly define for you the actual subjects that are being researched in this field.

This helped me a lot; rather than just intelligence, the term 'psychometrics' seems to refer to psychology as a whole.

I think that is not correct and not close to correct.

From these materials I gather that there is (or was) quite a deal of controversy among US psychologists about the book.

There was a lot of controversy outside of the field of psychometrics. This was largely due to ignorance of the findings of the prior 75 years. I assume you read and understood the letter to the Wall Street Journal that addressed 25 salient points from The Bell Curve (posted in another thread). The person who posted that letter also listed the names of the people who signed it. These people were not surprised at anything in the book, since they were familiar with the literature. It is obvious that the negative responses were largely from "outsiders" since those same people did not comment when Seligman's book was released about 2 years earlier. The press and liberals didn't have any idea that the white-black IQ gap had been quantified for at least 3/4 of a century. Spearman's Hypothesis was formulated in 1927 (from memory, you can verify the date) and remains accurate today. Bias in Mental Testing also went into considerable detail about the gap. In fact, the book was written largely to demonstrate the applicability of standard IQ tests to all population groups. All of Chapter 4 is devoted to the subject of IQ distribution. Anyone capable of reading the book (is is not pablum) in 1980 would have had no trouble understanding the details of the white-black gap. On page 99 there is a large graph of the normative population and of blacks. So, why the excitement, when The Bell Curve recited what was already a matter of history, going back to Spearman?

To be sure I don't misunderstand, are Andrews and Nelkin 'crackpots'?

Perhaps a better question to ask is what is the background of these two ladies? Are they schooled in psychometrics? Have they published in peer reviewed journals? Have they written recognized textbooks on intelligence? I have never heard of them. Can you tell me about their qualifications to make the sorts of comments that appear in that letter? I too did some research:
The late Dorothy Nelkin, a sociologist, was a professor at the New York University School of Law.
Lori B. Andrews
Distinguished Professor of Law; Director of the Institute for Science, Law and Technology; and Associate Vice President

As you can see, neither of these people are psychometricians and neither seems to have a close connection with that field of study. I do not understand the merits of criticisms from sociologists and lawyers who have not conducted psychometric research and are not experts in the field.

What about members of the APA taskforce - are they crackpots too?

I think I addressed the APA in my last message. The taskforce comments were vague and were apparently designed to say as little as possible. Do you have information as to the names of the task force members? Are they people who have published in this field?

 

[NoahAfrican]

You all have put up a good fight against Mandrak and his likes. However, it is a loosing battle. You all must understand and accept that logic is a poor weapon to employ against emotions. Mandrak has an emotional investment in these beliefs and no amount of intellectual and professional contradictions of the hypothesis of others, that he presents, will change his opinion.

I guess I have been around this block enough time to know intransigence and closed minds when I encounter such. However, your attempts are not in vain in that hopefully others who are silently reading will have the equal and opposite force (counter opinions and hypotheis) to offset his foolery...but rest asured that you will not change his opinion.

 

[Evo]

Perhaps a better question to ask is what is the background of these two ladies? Are they schooled in psychometrics? Have they published in peer reviewed journals? Have they written recognized textbooks on intelligence? I have never heard of them. Can you tell me about their qualifications to make the sorts of comments that appear in that letter? I too did some research:
The late Dorothy Nelkin, a sociologist, was a professor at the New York University School of Law.
Lori B. Andrews
Distinguished Professor of Law; Director of the Institute for Science, Law and Technology; and Associate Vice President

Dorothy Nelkin, Professor of Sociology, member of the Human Genome Project, here are some of her publications, these just from 1990-1995

Dreyfuss, Rochelle Cooper ; Nelkin, Dorothy
The jurisprudence of genetics.
Vanderbilt Law Review. 1992 Mar; 45(2): 313-348.
adoption ,autonomy , behavioral genetics , criminal law , DNA fingerprinting , employment , eugenics , family relationship , females , genetic counseling , genetic disorders , genetic screening , genetics , genome mapping , law , legal aspects , legal liability , mass screening , occupational exposure , parent child relationship , personhood , prenatal injuries , reproductive technologies , science , self concept , social discrimination , social impact , sociobiology , surrogate mothers , values , wrongful life

Nelkin, Dorothy
The double-edged helix.
New York Times. 1994 Feb 4: A23.
behavioral genetics ,eugenics , genetic disorders , genetic predisposition , genetic screening , genetics , genome mapping , human characteristics , mass media , social discrimination , social impact

Nelkin, Dorothy
The social power of genetic information.
Kevles, Daniel J.; Hood, Leroy, eds. The Code of Codes: Scientific and Social Issues in the Human Genome Project. Cambridge, MA: Harvard University Press; 1992: 177-190, 344-345.
behavioral genetics ,diagnosis , DNA data banks , economics , education , employment , genetic disorders , genetic screening , genome mapping , health care , insurance , law enforcement , legal aspects , mass screening , normality , prenatal diagnosis , risks and benefits , social discrimination , social impact , stigmatization

Nelkin, Dorothy
The rhetoric of scientific revolution. [Book review].
Hastings Center Report. 1992 Jul-Aug; 22(4): 38-39.
book review ,ecology , genetic intervention , genetic screening , genome mapping , industry , public policy , recombinant DNA research , regulation , risks and benefits , science , social impact , socioeconomic factors

Nelkin, Dorothy
Diagnosis: the social implications of emerging biological tests.
Blank, Robert H.; Bonnicksen, Andrea L., eds. Emerging Issues in Biomedical Policy: An Annual Review. Volume I. New York: Columbia University Press; 1992: 215-224.
behavior control ,behavioral genetics , biomedical technologies , dangerousness , data banks , diagnosis , employment , genetic disorders , genetic screening , genome mapping , health insurance , law enforcement , mass screening , mental health , prenatal diagnosis , psychiatric diagnosis , social control , social discrimination , social impact , stigmatization

Nelkin, Dorothy ; Tancredi, Laurence
Dangerous Diagnostics: The Social Power of Biological Information; with a new Preface.
Chicago, IL: University of Chicago Press; 1994. 207 p.
Originally published by Basic Books; 1989.
adults ,alcohol abuse , behavior control , behavior disorders , behavioral genetics , biomedical technologies , children , chromosome abnormalities , diagnosis , DNA fingerprinting , drug abuse , economics , education , forensic psychiatry , genetic disorders , genetic predisposition , genetic screening , health care delivery , industry , insurance , law enforcement , mandatory testing , mass screening , normality , occupational medicine , prenatal diagnosis , privacy , psychiatric diagnosis , social control , social discrimination , social impact , stigmatization , violence

Nelkin, Dorothy
Genome: the social power of biological tests (1).
International Journal of Bioethics. 1990 Sep; 1(3): 140-145.
behavioral genetics ,conflict of interest , diagnosis , economics , education , employment , eugenics , genetic disorders , genetic screening , genome mapping , health care , health insurance , institutional policies , mass screening , normality , physicians , public policy , social control , social discrimination , social impact

Nelkin, Dorothy
Living inventions: animal patenting in the United States and Europe.
Stanford Law and Policy Review. 1992-93 Winter; 4: 203-210.
accountability ,animal rights , decision making , drug industry , ecology , economics , genetic intervention , government regulation , human rights , hybrids , industry , information dissemination , international aspects , investigators , justice , morality , patents , political activity , public opinion , public participation , public policy , recombinant DNA research , risks and benefits , speciesism , transgenic animals , universities

http://www.csu.edu.au/learning/ncgr/gpi/odyssey/cloning/Nelkin_works.html

The other woman - Lori B. Andrews
Distinguished Professor of Law; Director of the Institute for Science, Law and Technology; and Associate Vice President

Since passing her bar exam the day Louise Brown, the first test-tube baby was born, Lori Andrews has become an internationally-recognized expert on biotechnologies. Her path-breaking litigation about reproductive and genetic technologies and the disposition of frozen embryos caused the National Law Journal to list her as one of the "100 Most Influential Lawyers in America."

Today, Professor Andrews is a distinguished professor of law at Chicago-Kent; Director of IIT's Institute for Science, Law and Technology; and in Spring 2002, she was a visiting professor at Princeton University. She received her B.A. summa cum laude from Yale College and her J.D. from Yale Law School.

Professor Andrews has also been involved in setting policies for genetic technologies. She has been an adviser on genetic and reproductive technology to Congress, the World Health Organization, the National Institutes of Health, the Centers for Disease Control, the federal Department of Health and Human Services, the Institute of Medicine of the National Academy of Sciences, and several foreign nations including the emirate of Dubai and the French National Assembly. She served as chair of the federal Working Group on the Ethical, Legal, and Social Implications of the Human Genome Project. She recently served as a consultant to the science ministers of twelve countries on the issues of embryo stem cells, gene patents, and DNA banking. She has also advised artists who want to use genetic engineering to become creators with a capital "C" and invent new living species.

Professor Andrews is the author of ten books

http://www.kentlaw.edu/faculty/andrews_bio.html

Sounds like they're qualified to me.

 

[nuenke]

In the meantime, can you point me to a paper describing the commonly accepted experimental protocols? I'm particularly interested in subject selection and the extent to which double-blind protocols are employed. Hmm. I'm still interested in knowing whether Jensen (and others) have been clear that their work has validity only in the geographical region in which it was conducted, or whether it can be used globally (and if so, why).Sorry that I wasn't clear.

A good book on psychometrics that goes into experimental protocols is:

Modern Psychometrics: The Science of Psychological Assessment by Rust and Golombok, 1999. I am sure Amazon has other textbooks available on the subject as well.

Also, the geographical region of study in intelligence is in fact global. See Lynn and Vanhanen's "IQ and the Wealth of Nations" and the numerous papers written following the books release two years ago.

 

[nuenke]

Sounds like they're qualified to me.

The three academic areas that do not reflect the scientific method includes cultural anthropology, social science and law, along with a few others. Of course, there is no way to have a scientific discussion of race and intelligence because humans become irrational in these areas: just like abortion, religion, and a host of other subjects.

When it comes to racial issues, humans fail the test of scientific investigation--it is just too political. The research into heuristics and biases, along with numerous other books are now exploring how humans are all about deception and self-deception. That is why we can pursue quantum mechanics and going to the moon, but we will deny there is such a thing as intelligence while putting decals on our bumpers stating "my son is an honor student at bid-deal high."

 

[Moonbear]

g is the source of broadest common variance in any given matrix of mental ability tests. Factor-loadings (including g-loadings) of mental tests are determined by factor analyzing the results of tests adminstered to multiple subjects. (In terms of the most widely used IQ tests, the vocabulary subtests tend to be revealed by factor analysis as having the highest g-loadings of any subtest.)

Since g is the most-general factor of mental-ability tests, it is the factor that is most predictive of general outcomes. Relatively narrow outcomes tend to be better predicted by narrower ability factors such as those that have been borrowed by Howard Gardner to form his list of "multiple intelligences."

I may sound really dense here, but I have to admit, this didn't make a whole lot of sense to me. "g is the source of broadest common variance..." So, is it a statistical measure? You give someone a bunch of tests, then compute the variance in those test results, and that gives you a result called g? Or is it some "thing" that supposedly causes that variance? From some of the other posts, I see that it's reported as a percentage. Percentage of what? If it's based on the results of IQ tests, then of course it would be correlated to IQ (something I've seen mentioned often in assorted threads here). So, how does it differ from IQ and the way IQ scores are calculated?

Or, perhaps another way of asking it is this: what does the score mean? If someone has a high g score, does that mean they are supposed to be more intelligent than someone with a low g score? Does it mean they are more consistent across different measures, such as verbal and analytic skills? I know much of the debates here are dealing with what g might predict, but that's not what I want to know, I want to know what it means in the here and now. What do we KNOW about it, not what we think it might tell us about the future? Or is it just a form of mathematical modeling, attempting to fit things like IQ, test scores, and some sort of measure of real life ability into some sort of equation/model for just that purpose, trying to predict outcomes based on just a few of those measures?

Correlations are fine and interesting and lead to hypotheses to test, but they do not prove causation. It seems there is a lot of weight being put onto correlations here and in related threads.

Sorry if I'm being very verbose and asking essentially the same question many different ways, but I just haven't seen an answer that really holds much meaning to the question I'm really trying to ask, so I'm trying to make it clearer just what it is that has me confused that I'm trying to get an answer about.

 

[selfAdjoint]

I may sound really dense here, but I have to admit, this didn't make a whole lot of sense to me. "g is the source of broadest common variance..." So, is it a statistical measure? You give someone a bunch of tests, then compute the variance in those test results, and that gives you a result called g?

You give a lot of people a lot of different IQ tests. You take all the scores, by person, test, and question number, and do a statistical procedure called factor analysis, trying to find which combination of questions reduces the most variance on the data. This is like a regression, only more so. The result will be a set of subsets of questions, ordered by effectiveness in reducung variance. The top candidate is called the first principal component. You then identify the questions and convert their scores to a number. Spearman's g is this number for the first principal component of just about every IQ test and surrogate ever invented. It is enormously stable and correlated with things like the SAT, the Armed Forces tests, and so on. It also has physical correlates like measured reaction time and volume of gray matter in the prefrontal cortex.

 

[Moonbear]

You give a lot of people a lot of different IQ tests. You take all the scores, by person, test, and question number, and do a statistical procedure called factor analysis, trying to find which combination of questions reduces the most variance on the data. This is like a regression, only more so. The result will be a set of subsets of questions, ordered by effectiveness in reducung variance. The top candidate is called the first principal component. You then identify the questions and convert their scores to a number. Spearman's g is this number for the first principal component of just about every IQ test and surrogate ever invented. It is enormously stable and correlated with things like the SAT, the Armed Forces tests, and so on. It also has physical correlates like measured reaction time and volume of gray matter in the prefrontal cortex.

Thank you so much for taking time to answer my questions! This is so much clearer to me. So, can any conclusions be drawn from the subset of questions that is used to compute the score for g? Do they have in common requiring a particular type of ability? As possible examples, spatial relations, verbal skills, analytical skills, forming associations between two different concepts, memorization tasks. The reason I'm asking is that now that I understand what g is, I'm wondering what about it makes it stable. Perhaps certain mental abilities are more important to survival on a more basic level, so are better conserved, whereas others are a "luxury" for those who have time to ponder the day away, so more variable? For example, key skills to surival...finding and remembering the places where food is, remembering which things made you sick so aren't good food, and remembering how to get from where you are to those places where the food are. So, basically, some memorization tasks and some spatial relations tasks. You don't need to know how to count to know if your belly is full, you don't have to add or subtract or multiply, you don't have to know a lot of words, though some basic communication to tell your family members where to find the food would be good, but you would need to make associations between different events...ate the green berries and later got a tummy ache, so green berries aren't good food. When it comes to solving problems that ask you to make analogies or find synonyms to words no normal person uses in every day conversation, I'd expect a lot more variation in ability simply because there is no real need for this skill.

 

[Mandrake]

Originally Posted by Mandrake
Do you mean her "kangaroo" link? I had seen that one before. It was put up by Steve Kangas, who says on his page that he is a student seeking a degree in Russian Studies. Is that a good source of scientific information? He identifies himself as an ultra-liberal and obviously has a very strong political agenda. If you look at his references, you will see that they include these scientific sources:
The San Francisco Chronicle
People For The American Way
USA Today
Boston Globe
The New York Times Magazine
Discovery Journal
The Nation,
Rolling Stone
Newsday
Newsweek.

Evo: You intentionally omitted all of the references from the American Psychological Association and the Human Genome Project.

You noticed? Maybe you thought my comment about "scientific sources" was serious? Guess not. Let me explain it to you ... I was making fun of the outrageous sources that were listed. I do not object to the use of a source that may have some scientific merits. Guess the subtlety was a bit too much for you.

How do you expect anyone to believe anything you say when you try to deceive them?

I made the horrible mistake of thinking that readers could understand what I wrote. You didn't.

If you have nothing to hide, why do you intentionally skew this list? Here are the sources Mandrake left out. I am disappointed in you Mandrake, I thought we could start over and debate this reasonably. Since you had to pick the other references from around them, you went to a deal of trouble to omit them.

A little testy today? I am sorry I made fun of the newspaper sources that you apparently believe are vehicles for serious science.

3. Tori DeAngelis, "Psychologists question findings of Bell Curve," APA Monitor, American Psychological Association, October, 1995.

This person identifies herself as a "writer." She does write about subjects that pertain to intelligence. So does the guy who is majoring in Russian Studies (Kangas). Does this person have any real credentials? The problem with the references you and others have produced is that they are precisely from the uninformed groups who have an ax to grind, but who are ignorant of the reliant science.

5. "APA Task Force Examines the Knowns and Unknowns of Intelligence," American Psychological Association, Press Release, September 15, 1995.

I have read this. I assume you have read it. What parts support your claims that The Bell Curve is invalid and that its authors are racists? Do you believe that the entire group of practicing psychometricians are evil racists? If so, does that go all the way back to Spearman?

11. Lori B. Andrews, Dorothy Nelkin and endorsing members of the Human Genome Project, "The Bell Curve: A Statement," letter to the editor, Science, January 5, 1996.

What expertise do you ascribe to a sociologist and a lawyer? These people are not experts in the field of psychometrics, nor have they published research findings in psychometrics. They are simply critics, who fit the mold of your newspaper and Russian Studies experts. Why are you so attracted to people who have little commitment to the study of intelligence, while holding in contempt the scientists who have devoted their entire careers to it? When you are ill, do you hold physicians in contempt and seek help from a newspaper?

Originally Posted by Mandrake
APA is not a group of psychometricians, it is a group of psychologists, a few of whom may be psychometricians.

Evo: You seem to think quite highly of psychometricians, when I have sometimes heard "psychometrics" referred to as "voodoometrics", which I think isn't nice since there are good people and bad people and I disagree with labeling groups of people, it isn't right or completely true.

If we were discussing astronomy, would you think it appropriate to take expert commentary from astronomers, or lawyers? If we were discussing insects, would you want to be quoting an entomologist, or someone who describes himself as an admirer of Russians and an ultra liberal?

Originally Posted by Mandrake
When a letter goes out, it is not the joint finding of the entire membership nor is it the joint finding of those members who are actually qualified to make a judgement.
Evo: Which is exactly why the APA formed an unbiased committee , including Thomas Bouchard. You can't get much more pro Bell Curve than that.

The APA report addresses some issues quite well; it addresses others incompletely; and it misrepresents some issues. Consider the discussion about heritability. They discuss only MZA data and say nothing about path analysis. Why? The results are in agreement, but the literature claims are that path analysis is more robust. In this area, they had no way of knowing what would later be discovered by Dr. Paul Thompson at UCLA: "We were stunned to see that the amount of gray matter in frontal brain regions was strongly inherited, and also predicted an individual's IQ score..." His work was done with MRI. Their coverage of the Scarr-Weinberg findings was poor.

 

[Mandrake]

Since you (Evo) place a lot of weight on the people who served on the task force, I would like to make observations about some of them, supplemented by some of their material:

Ulric Neisser, Emory University (chair of the task force)
A real psychometrician. His interest has been in the Flynn Effect.

Thomas J. Bouchard, Jr., University of Minnesota

The scientific study of general intelligence: Tribute to Arthur R. Jensen
H. Nyborg (Ed.), 2003, Elsevier, Oxford, UK, ISBN0080437931
Thomas J. Bouchard:
This is a gem of a book and a fitting honor to a distinguished scientist and scholar.
Arthur Jensen has single-handedly reinvigorated the scientific study of human intelligence and his magnum opus—The g Factor: The Science of Mental Ability (Jensen, 1998) (henceforth, SMA)—will remain a definitive work for many years to come. As Jensen has shown, g lies at the nexus of a large set of causal empirical relationships that encompass every aspect of human life, from birth to death. This nexus links psychology to biology, genetics, neuroscience, sociology, demography, the humanities, and the arts. There is an emerging discipline called the Epidemiology of Human Intelligence. The book under review follows the Bell Curve (Herrnstein & Murray, 1994) and SMA in helping lay the foundations of that discipline.

Description versus strong inference --Thomas J. Bouchard Jr.
Intelligence, Volume 29, Issue 2 , March-April 2001, Pages 187-188
Since Scarr (1997) has shown quantitatively that socialization effects, found in studies of biological families, are confounded and almost all such effects can be explained by genetic factors, adoption controls are mandatory. Hand waving away the competing genetic hypothesis simply will not do.

A. Wade Boykin, Howard University
His interest seem to be restricted to blacks. He even wrote instructions for black psychologists, as if the skin color of a psychologist requires a different set of research instructions.

Nathan Brody, Wesleyan University

Here are a few of his comments from Kings of Men: Introduction to a Special Issue of the Journal of INTELLIGENCE (1998)

I believe that anyone who wishes to write about the issue of race and intelligence must acknowledge Jensen's formidable contributions to this topic and his comprehensive knowledge of this area of research. Jensen's book on bias in testing is an extraordinarily thorough and scholarly analysis of the issue of test bias (Jensen, 1980). I like to compare this book with another book that I admire greatly, Paul Meehl's monograph on Statistical vs. Clinical Prediction (Meehl, 1954). Both books serve to define the principal issues that must be understood in addressing the topics that they consider. Both books develop their arguments with unusual clarity and sophistication. And, to a remarkable extent, the conclusions reached in both books have stood the test of time and become part of the canon of empirically established generalizations that define our knowledge of important topics. Jensen established what is now close to the received wisdom of knowledgeable students of intelligence -- tests of intelligence are equally valid indices of the performance of individuals who differ with respect to their racial identification. In several technical senses of the term, they are not biased -- a conclusion endorsed in the recently published report of the American Psychological Association's task-force on intelligence composed of individuals with diverse views of the field (Neisser et al., 1996).

Jensen is not an ideologue or a person who is not able to respond to criticism in a fair way. He is a scientist with formidable technical skills who strives for an understanding of the topics that he addresses. In this regard, his work is a model of scientific decorum. We should all strive to emulate his ability to test our beliefs against a recalcitrant reality that often is resistant to our ability to represent it in distorted ways. In the long run, if we are clever and honest, it will impose its structure and truth on us rather than ours on it.

In my opinion, Jensen's most important contribution to the field is contained in his new book on the g factor (Jensen, 1998). In the first paper dealing with g, Spearman attempted to determine the g loadings of different measures of intelligence (Spearman, 1904).

Jensen (1998) links the g vector to several biologically relevant vectors. He notes that Pedersen et al. (1992) obtained heritability values for different tests in a battery of tests of intelligence administered to a sample of older Swedish adult MZ and DZ twins reared together and apart. The vector defining the heritability of the tests is correlated with the vector defining the independently ascertained g loadings, r = .77. Jensen provides additional evidence based on Wechsler sub-test g loadings indicating that the vector of g loadings is correlated with the vector of heritability values for Wechsler sub-tests.

Jensen's analyses of the correlates of g vectors provide the quantitative underpinning for what has long been apparent -- g is a biologically influenced heritable component of the commonality among diverse measures of intellect that is related to the ability of individuals to acquire knowledge in formal academic contexts. Perhaps we have always known this, but following Jensen's highly original use of analyses of the correlates of g vectors we know this with a kind of quantitative precision not heretofore available.

Jensen's work on the correlates of the g vector reveals some of his best attributes -- an ingenious ability to develop quantitative analyses that address fundamental issues in highly original ways that advance our knowledge of critical issues in the field.

Stephen J. Ceci, Cornell University
Focus is on children. His positions on many issues are in conflict with real world findings.

Diane F. Halpern, California State University, San Bernadino
Her work is in the area of family issues and children, not psychometrics.

John C. Loehlin, University of Texas, Austin

His comments pertaining to the Texas Adoption Project from Intelligence, Volume 24, Issue 2 , 1997, Pages 323-328

The children have so far been studied twice-once at the time of the initial study, when they averaged about 8 years old (although spanning a range of ages), and again, roughly ten years later, when most of them were late adolescents or young adults. The results with regard to IQ were straightforward enough to delight even a Willer-man. The adoptive childtens’ IQs resembled those of their birth mothers, whom they had never seen, more than they did those of their adoptive mothers, with whom they had lived all their lives. Biologically unrelated children reared as siblings (pairs of adopted children in the same home, or an adopted and a biological child) resembled one another to some degree at the time of the first testing, when they were still children, but by the time of the second testing, when most of them were late adolescents or young adults, these cormlations had dropped essentially to zero. That is, children who grew up together but who did not share a genetic resemblance were somewhat similar in their measured IQs when they were young, but by late adolescence their genetic differences had expressed themselves, and they were as different as any two randomly-selected members of the (somewhat restricted) population to which they belonged.


Robert Perloff, University of Pittsburgh
Professor of Business Administration. Expert? :-)

Robert J. Sternberg, Yale University

I have discussed Sternberg here before. He advocates his Triarchic Theory, which does not stand up to scrutiny, as has been demonstrated dramatically by Linda Gottfredson.

Originally Posted by Mandrake
At this point, the only people doubting the 100 year study of the variance in intelligence are crackpots.
Evo: So, you claim the people listed above are crackpots? Nice.

Evo, your personal contempt has replaced rational thought. Do you seriously think that the people in question doubt the variance in intelligence that has been demonstrated over the past century? Try reading some of the comments they made, which I quoted. You really don't get it do you?

Here is another link on The Bell Curve from the University of Wisconsin.

Did you read this article? If so, what are your thoughts about it? Just posting a link by two economists doesn't add much to the discussion. Is there some reason why you consider that psychometrics is a subcategory of economics? My reading of the paper showed that the authors used approaches that appear to be reasonable, but which, as usual, ignore the details of what is known about the subject. This is apparent in their discussion of heritability. What are your deepest and most profound thoughts on this paper? Oh, I forgot to ask, did you read it before posting the link??

 

[Mandrake]

Dorothy Nelkin, Professor of Sociology, member of the Human Genome Project, here are some of her publications, these just from 1990-1995

I had already looked and found that these women had no background in psychometrics. Sorry to inform you, but the areas addressed by their publications (however important they may be for other purposes) are not sufficient to qualify them to address psychometric issues with authority. It remains amazing to me to see how important it is to you to show us all that there are people in various other fields who don't understand psychometrics, but who say what you want to hear.

 

[Moonbear]

Of these, the brain volume subject has received particularly prolonged study. The development of fMIR technology has enabled researchers to identify and measure the volumes of specific parts of the brain and to correlate them to _g_ (even group factors show up as specific locations). The research was done by Richard Haier and was presented at the 2003 ISIR conference. This is cutting edge material.

As promised, I'm trying to get back to this topic when less tired...and now I also have a better idea of what "g" is, so that helps.

It occurs to me that my initial confusion on this is that my interpretation of "specific" brain regions is probably different from what you meant. Using MRI, you can measure gross brain structures that have clearly defined boundaries, such as cortex, cerebellum, hippocampus, corpus callosum. You can also use methodologies that tell you what areas are "activated" during certain tasks by measuring changes in blood flow or glucose uptake, but these sorts of analyses are often open to varied interpretations (even in less controversial areas than intelligence), and it doesn't reflect the size of that brain area, just the part of it that is being used. The two general interpretations that can be taken when there is a group difference in the size of an area that "lights up" on an MRI is that either there is more activity, so a greater ability to use that region in that group, vs the group that shows less activity may be more efficient in processing of that task, so uses only a smaller area of the brain. The other controversy is whether blood flow and glucose uptake really translate into actual function. But for now, people are generally willing to accept that this is the case, and that controversy is more a nuance of the field. When I think of "specific" brain areas, I'm thinking of specific nuclei within a region. For example, in MRI, you can measure the volume or thickness of cortex in a given slice, and you could use some other landmarks to identify, for example, prefrontal cortex (I picked that because it's an area SelfAdjoint mentioned as correlating to g), but, within prefrontal cortex, there are multiple nuclei such as the infralimbic nucleus and prelimbic nucleus. These different nuclei contain a variety of different neuronal subtypes that differ between the nuclei both in neurotransmitters and receptors as well as functions...you get a very different neurological/behavioral outcome if different nuclei are lesioned, for example. And a variety of functions are attributed to this area, including things like working memory, impulse control, addiction, sexual behavior, some better described in the literature than others. I'm not sure if an MRI scan would really pick up differences associated with just parts of the PFC. And saying something is correlated to a change in the size of the PFC doesn't mean a lot to me...I would want to know which nucleus? Which cells in the nucleus? If someone had a deficit in the area related to working memory, that would certainly explain a lower test score, however, deficits in other areas might also lead to problems with taking tests that isn't related so much to intelligence as to just staying focused on the test.

The point of my comment is that these differences appear as group differences and correlate with _g_ independently of the group identity. For example, that means that the mean brain volume differences between US blacks and US whites are as expected, given the differences in mean IQs for these two groups. Chronometric measurements similarly vary between groups in proportion to the observed differences in _g_ between the groups.

I just found this fascinating article. It does show a clear relationship between IQ and head circumference, though they focus on the extremes, where head circumference was at or below 2 SD from the mean. The main conclusion is that head circumference and brain volume are related to IQ, and that this smaller head circumference and brain volume are strongly related to early childhood malnutrition. In this study, they were assessing adults, but the correlation to malnutrition is based on their earlier work that they also cite. There is also a really interesting paragraph in the introduction that explains that comparisons between racial groups are not valid, even when using height and weight to correct for head circumference variations, because height and weight are not unformly covariate with head circumference. Here is the citation and some excerpts (my editing for clarity is in red text).

Neuropsychologia 42 (2004) 1118–1131
Head size and intelligence, learning, nutritional status and brain development Head, IQ, learning, nutrition and brain
Daniza M. Ivanovic, Boris P. Leiva, Hernán T. Pérez, Manuel G. Olivares, Nora S. D´?az , Mar´?a Soledad C. Urrutia, Atilio F. Almagià, Triana D. Toro, Patricio T. Miller, Enrique O. Bosch, Cristián G. Larra´?n

To view the full article, go to: http://dx.doi.org and in the text box, enter:
doi:10.1016/j.neuropsychologia.2003.11.022

Abstract
This multifactorial study investigates the interrelationships between head circumference (HC) and intellectual quotient (IQ), learning,
nutritional status and brain development in Chilean school-age children graduating from high school, of both sexes and with high and low
IQ and socio-economic strata (SES). The sample consisted of 96 right-handed healthy students (mean age 18.0 ± 0.9 years) born at term.
HC was measured both in the children and their parents and was expressed as Z-score (Z-HC). In children, IQ was determined by means
of theWechsler Intelligence Scale for Adults-Revised (WAIS-R), scholastic achievement (SA) through the standard Spanish language and
mathematics tests and the academic aptitude test (AAT) score, nutritional status was assessed through anthropometric indicators, brain
development was determined by magnetic resonance imaging (MRI) and SES applying the Graffar modified method. Results showed that
microcephalic children (Z-HC ? 2S.D.) had significantly lower values mainly for brain volume (BV), parental Z-HC, IQ, SA, AAT, birth
length (BL) and a significantly higher incidence of undernutrition in the first year of life compared with their macrocephalic peers (Z-HC >
2 S.D.). Multiple regression analysis revealed that BV, parental Z-HC and BL were the independent variables with the greatest explanatory
power for child’s Z-HC variance (r2 = 0.727). These findings confirm the hypothesis formulated in this study: (1) independently of age,
sex and SES, brain parameters, parental HC and prenatal nutritional indicators are the most important independent variables that determine
HC and (2) microcephalic children present multiple disorders not only related to BV but also to IQ, SA and nutritional background.

Some authors emphasise that, at present, there is no
meaningful basis for the comparison of brain sizes within
and between racial groups and sexes; the control for body
size across racial groups (and sexes) is rendered difficult
because bodies do not just differ only in H(Height) and W (Weight)(Peters
et al., 1998). In the present study, the correlations between
BV (Brain Volume)and H and W were very low, as we informed in a
previous report (Ivanovic et al., 2002) and the analysis of
covariance (Guilford & Fruchter, 1984) revealed that no
significant effect of sex, H and W was observed for BV;
however, despite of this, values were adjusted by body size
(W and H) but were so similar to absolute values that only
these are reported in the present study.

HC (Head Circumference) has been recognised as the most
sensitive anthropometric index of prolonged undernutrition
during infancy, associated with intellectual impairment especially
verbal IQ, such as in our study (Ivanovic et al.,
2000d; Leiva et al., 2001; Stoch et al., 1982). Undernutrition
was significantly more prevalent in children with a low HC
(<?2 S.D.) who presented the lowest verbal IQ, BV (Brain Volume) and
APD (Anterior-Posterior Distance of the brain) values and this latter finding is especially outstanding
since APD involves language and visualisation areas (Stoch
et al., 1982; Willerman et al., 1991); this could explain that
in children with low HC (<?2 S.D.), verbal skills are more
deteriorated than non-verbal skills (Ivanovic et al., 2000d;
Stoch et al., 1982). In children with HC >2 S.D., verbal IQ
was higher than nonverbal IQ and in groups with a “normal
HC “ (mean±2 S.D.) similar values were found between total,
verbal and non-verbal IQ although IQ was significantly
higher in 0–2 S.D. group. Findings from several studies
emphasise that among preschoolers HC might reflect better
than body H the impact of nutritional deficiencies at an
early age; this measurement is useful in the identification of
the period during which malnutrition occurred (Johnston &
Lampl, 1984; Malina et al., 1975).

It has been suggested that individual differences
in myelination, which affects neural transmission
rates, may be the basis for the HC–BV–IQ correlation although
there is a low correlation between neural speed and
mental speed, suggesting that other mechanisms must be involved
(Miller, 1994; Tan, 1996; Vargas et al., 2000;Wickett
& Vernon, 1994). Delayed myelination and abnormalities in
neuron migration have been described as the most predominant
disorders in children with associated neurologic findings...

 

[Evo]

You noticed? Maybe you thought my comment about "scientific sources" was serious? Guess not. Let me explain it to you ... I was making fun of the outrageous sources that were listed. I do not object to the use of a source that may have some scientific merits. Guess the subtlety was a bit too much for you

A little testy today? I am sorry I made fun of the newspaper sources that you apparently believe are vehicles for serious science..

They are references to where certain quotes and other information came from, they aren't supposed to be scientific references. I thought that was obvious, I guess not.

I will respond to the rest later when I have more time, it might be tomorrow.

 

[Evo]

I had already looked and found that these women had no background in psychometrics. Sorry to inform you, but the areas addressed by their publications (however important they may be for other purposes) are not sufficient to qualify them to address psychometric issues with authority. It remains amazing to me to see how important it is to you to show us all that there are people in various other fields who don't understand psychometrics, but who say what you want to hear.

Like it or not Mandrake, those two are extremely qualified. I notice that you tend to dismiss and even skip over anyone or anything that disagrees with you, as in your list of the APA panel. If you agree with them, you praise them to the heavens and post comments of theirs that make you happy, if you don't agree with them, you post nothing of what they say and skip over them. You are so funny and predictable.

 

[Moonbear]

I've run out of characters in my above post to edit it...those strange apostrophe's followed by question marks in the authors names are supposed to be the letter i with an accent. For some reason, the characters didn't display correctly.

 

[Evo]

I just found this fascinating article.

Well, I was going to get some work done, but your post and this article are too interesting.

I went to read the rest of the article and I can't. I don't have a password.

 

[hitssquad]

What types of abilities are characteristic of g

can any conclusions be drawn from the subset of questions that is used to compute the score for g? Do they have in common requiring a particular type of ability? As possible examples, spatial relations, verbal skills, analytical skills, forming associations between two different concepts, memorization tasks.

• High g Loading
  Matrix relations (.94)
  Generalizations (.89)
  Series completion (.87)
  Verbal analogies (.83)
  Likeness relations (.77)
  Problem arithmetic (.77)
  Paragraph comprehension (.73)
  Perceptual analogies (.70)
  
  
• Low g Loading
  Maze speed (.04)
  Crossing out numbers (.12)
  Counting groups of dots (.14)
  Simple addition (.23)
  Tapping speed (.24)
  Dotting speed (.27)
  Paired-associates memory (.27)
  Recognition memory (.31)

(Arthur Jensen. The g Factor. p35.)

Do they have in common requiring a particular type of ability?

• Spearman concluded that the tests that best reflect g are those that most involve the "eduction of relations and correlates." These are the tests that require inductive and deductive reasoning, grasping relationships, inferring rules, generalizing, seeing the similarity in things that differ (e.g., reward-punishment) or the difference between things that are similar (love-affection), problem solving, decontextualizing a problem (that is, distinguishing between its general, or essential, features and its specific, or nonessential, features). These all manifest the second and third "laws" of noegenesis--the eduction of relations and of correlates. They are contrasted with tests that call mainly upon speed of execution of simple tasks, performance of repetitious acts, simple cued recall of prior learned responses, execution of a practiced sequence or chain of responses, and direct imitation of another person's specific action without conscious transformation.

(Ibid. pp35-36.)


However:

• Unlike group factors, g cannot be described in terms of the superficial characteristics or information content of the tests in which it is loaded. All mental tests have some degree of g loading and even extremely dissimilar tests (e.g., sentence completion and block designs) can have nearly equal g loadings. Group factors, on the other hand, are labeled and described in terms of the obvious characteristics of the kinds of tests that load on them (such as verbal, numerical, spatial visualization, memory, mechanical, to name a few of the established group factors).
  
  Further, g is not describable in terms of any pure or unique behavior... There is no single distinct type or class of behavior or materials required for the manifestation of g... The fact that a certain class of tests measures g more efficiently than other tests does not qualify the characteristics of the former tests to be considered the "essence" or "defining characteristics" of g.

(Ibid. pp91-92.)

• The Confusion of g with Mental Processes. It is important to understand that g is not a mental or cognitive process or one of the operating principles of the mind, such as perception, learning, or memory... ...g only reflects some part of the individual differences in mental abilities...

(Ibid. p95.)

• The knowledge and skills tapped by mental test performance merely provide a vehicle for the measurement of g. Therefore, we cannot begin to fathom the causal underpinning of g merely by examining the most highly g-loaded psychometric tests.

(Ibid. p74.)

When it comes to solving problems that ask you to make analogies or find synonyms to words no normal person uses in every day conversation, I'd expect a lot more variation in ability simply because there is no real need for this skill.

A skill is not an ability. Skills result from practice, whereas abilities are inherent. However, higher ability results in faster and ultimately greater skill gain from any given amount of practice. This is why skill testing can indirectly indicate ability level.

As far as "no real need for" abilities that are characteristically highly g-loaded, every human activity is g-loaded to some extent, and persons with higher levels of g perform these activities more proficiently:

• The effects of g encompass a broader range of uniquely human phenomena than any other psychological construct... Applied research has concentrated on the importance of g in education, employment, economic development, health, welfare dependency, and crime.

(Ibid. p545.)

 

[Moonbear]

Well, I was going to get some work done, but your post and this article are too interesting.

I went to read the rest of the article and I can't. I don't have a password.

Well, at least I won't have to feel bad about keeping you from doing your work. Sorry about that. I thought that link I provided got me there without going through my university library...I guess it still knew

 

[Moonbear]

Hitsquad, all the information you've provided today is incredibly helpful! I feel I have a much better grasp of this subject now. Actually, a lot of what you included in this last post (#45) makes a lot of intuitive sense about what I've noticed in terms of my students and how well they learn.

Despite what an old professor once told me (he was quite fond of Piaget), I've found that students can be taught to make and understand relationships between things (that old prof told me they just reach that developmental stage on their own and some never do). The ability to identify relationships, especially complex relationships, really seems to reflect a student's likelihood of success, certainly as a scientist (there comes a point where rote memorization just doesn't carry you any further). So, it seems from what you're saying about g, is that it's sort of halfway between my views and my old prof's views. Students probably all possesses the ability to identify those relationships among concepts, but some are slower than others to develop it and express the skill, and with some coaching, I can help them develop that ability into actual skill.

What you've posted isn't nearly so bleak sounding as the way I've seen it interpreted in other threads. Others seem to suggest (or maybe it was my misunderstanding of what they were saying) that if someone has a low g score, then they have no hope of doing what those with a high g score can do, but instead, it may just take them a little more time to get there. Well, that makes sense. We all know there are slow learners and fast learners. Sure, there are some people who have a developmental defect who just lack the brain cells to ever perform beyond a certain level, but I like to be an optimist and think that those within that broad range of "normal" are all equally capable of achieving the same thing, though those at one end of that normal spectrum may take a little longer than those at the other end.

 

[hitssquad]

The teaching and shape of the population distribution of g

I feel I have a much better grasp of this subject now.

In that case, you probably have a looser grasp.

I've found that students can be taught to make and understand relationships between things

Oppositely, research has never been able to demonstrate any rise in g following intellectual exercise.

The ability to identify relationships

g is not an ability.

Students probably all possesses the ability

g is not an ability.

to identify those relationships among concepts, but some are slower than others to develop it and express the skill

Identification of novel relationships does not demonstrate skill. If it did, identification of novel relationships could be taught and learned.

and with some coaching, I can help them develop that ability into actual skill.

No one has ever been able to successfully coach rises in g under controlled, documentable conditions.

Others seem to suggest that if someone has a low g score, then they have no hope of doing what those with a high g score can do

Someone with any given reliably-attained g score has no hope of successfully executing any task with a g threshold above his measured level of g.

but instead, it may just take them a little more time to get there.

No.

Sure, there are some people who have a developmental defect who just lack the brain cells to ever perform beyond a certain level, but I like to be an optimist and think that those within that broad range of "normal" are all equally capable of achieving the same thing, though those at one end of that normal spectrum may take a little longer than those at the other end.

This is analogous to the pre-Newton conception of gravity as affecting ballistic objects only at certain critical points in their flight paths. IOW, it was once thought that ballistic objects fly in perfectly straight lines to the apexes of their flight paths, then, once there, suddenly start dropping straight down. Your IQ distribution would have all of the "middle" people at exactly IQ 100 and a few retardates at a given retardate level and a few gifteds at a given gifted level. No one would have an IQ of 110, and no one would have an IQ of 90.

Contrarily, research has demonstrated that:

• There are plausible reasons ... for assuming that individual differences in g have an approximately normal, or Gaussian ("bellshaped"), distribution, at least within the range of ±2σ from the mean. That range is equivalent to IQs from 70 to 130 on the typical IQ scale (i.e., μ = 100, σ = 15).

(Arthur Jensen. The g Factor. p88.)

I like to be an optimist and think that those within that broad range of "normal" are all equally capable of achieving the same thing

There has not been presented any reasoning why a possibility of massive equality in distribution of general mental ability should have any relationship with optimism.

 

[Mandrake]

So, can any conclusions be drawn from the subset of questions that is used to compute the score for g? Do they have in common requiring a particular type of ability?

When a test item requires thinking, it always calls on _g_. If a task has been learned to the point of automatic response, it is not calling on _g_ and is an example of a learned response. You can teach people to increase forward digit span, but in so doing, testing them on that ability is not as _g_ loaded as it would be if they were not trained. When they are then tested or reverse order digit span, they will not show that ability gains that were learned in forward recall.

As possible examples, spatial relations, verbal skills, analytical skills, forming associations between two different concepts, memorization tasks.

The items you listed are generally extracted at the second order of a factor analysis and are called group factors. Each of them is loaded on _g_, _s_, and _e_. The third order extraction yields _g_, which is the variance that is common to all of the group factors.

The reason I'm asking is that now that I understand what g is, I'm wondering what about it makes it stable.

_g_ is relatively stable over most of adult life and is so because it is rooted in physiology. I have previously listed the biological correlates of _g_. Such critical factors as nerve conduction velocity are biologically stable. The same applies to the degree of myelination. In old age, these may degrade and reduce intelligence. Some diseases may do the same thing. MS causes demyelination and causes IQ to decline.

 

[Mandrake]

Like it or not Mandrake, those two are extremely qualified.

I don't doubt that they are qualified in their fields. If you wanted to hire someone to represent you in a court of law, would you hire a psychometrician or a lawyer?

There is no requirement that a psychometrician hold a particular university degree. This is especially so because the field of psychometrics is quite removed from much of psychology and makes particularly heavy demands on statistical knowledge and laboratory research. The thing that distinguishes a psychometrician (or other specialist) is his devotion to the subject at hand, years of study, years of research, and participation in the publication of peer reviewed research. The women you listed are not qualified to peer review psychometric research.

I notice that you tend to dismiss and even skip over anyone or anything that disagrees with you, as in your list of the APA panel.

The APA group was selected for what appears to be political purposes. The APA is not a psychometric organization and as such, contains a lot of membership that is unqualified to deal with the subject. My observation is that you prefer comments from sources in proportion to their distance from the subject, wanting to believe only the things that originate from layman sources.

If you agree with them, you praise them to the heavens and post comments of theirs that make you happy, if you don't agree with them, you post nothing of what they say and skip over them.

If I know that the person is or is not qualified, I say so. You can always disregard my comments or call me a liar (as you have already done). That does not change my assessment. If I know nothing about the person, I cannot comment, can I?

You are so funny and predictable.

It is very kind of you to say so. This is an improvement over being called a racist and liar. I wonder if you interact with people in person with the same rudeness that I have seen in your messages?

I have a serious suggestion for you: Don't read my messages. For whatever reason, you cannot react to what I write in a civil way nor do you contribute positively to the ideas presented. As an alternative, simply read the comments by hitsquad. Read the recent ones he has posted in this thread in the past two days. Try to understand what he has presented and you will learn something useful about psychometrics. You are wasting your time being combative with me.