Scientific American and Spearman's g.

bpesta22

Cereal Killer
bpesta22
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For those following the other IQ thread-- not so much the main combatants, but anyone on the fence trying to decide what they think about IQ tests:

Here is a short article in Scientific American by Linda Gottfredson. She's a big name in psychometrics, but note that this ain't no psych journal publishing her claims.

I'm citing it here in a new thread because I think its very consistent with what I've been arguing (perhaps showing at least that I'm not making it up), and is a nice lay person's summary of the state of the art regarding g (with all claims passing American Scientists' peer review process).

http://www.psych.utoronto.ca/~reingold/courses/intelligence/cache/1198gottfred.html
 
I at least appreciate this thread. Those giant threads intimidate me...
 
Complexity said:
Wrong again.

You had no good reason to start yet another thread on this topic.
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In your opinion-- I see now 2 threads on page 1 on IQ. Wow, talk about spam!

One doesn't have to look far here to see threads that probably have no good justification for being....

Who gets to pick n chose which threads have good enough reason to start?

I say let the market sort it out. If no one else replies; so be it.
 
You participated in several threads on this subject.

If you insist on starting another thread to spread your gospel, I'll just have to jump in to counter your junk.

The people who claim to measure intelligence by means of IQ testing to estimate g are participating in an intellectual fraud, knowingly by some, through laziness and ignorance by others.

bpesta22 is one of these people.

These people have done, and will continue to do, a great deal of harm.

They have too much of a vested interest in their approach, and too little perspective and integrity, to address valid criticism and reconsider their field.

Their methods and their understanding of intelligence will, many years from now, be seen to be on par with feeling the skull for bumps.

Shame on them.
 
Complexity said:
You participated in several threads on this subject.

If you insist on starting another thread to spread your gospel, I'll just have to jump in to counter your junk.

The people who claim to measure intelligence by means of IQ testing to estimate g are participating in an intellectual fraud, knowingly by some, through laziness and ignorance by others.

bpesta22 is one of these people.

These people have done, and will continue to do, a great deal of harm.

They have too much of a vested interest in their approach, and too little perspective and integrity, to address valid criticism and reconsider their field.

Their methods and their understanding of intelligence will, many years from now, be seen to be on par with feeling the skull for bumps.

Shame on them.
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Hmmm...I smell a political agenda in your criticisms. You also lack the credentials to go toe to toe with Pesta intelligently on the subject, as far as I can tell.

AS
 
AmateurScientist said:
Hmmm...I smell a political agenda in your criticisms. You also lack the credentials to go toe to toe with Pesta intelligently on the subject, as far as I can tell.

AS
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No political agenda, just disgust at people who have made an industry out of oversimplifying something truly important and portray it as science.

Statistical analysis is not my area.

Intelligence is an abiding interest of mine, aspects of which are relevant to my research. Most of my graduate work involved the study of intelligence.

I'll leave the arcana of IQ testing to bpesta. Whatever they are measuring, I don't think it is intelligence.

He recommended an article, I'll recommend a book: Stephen Jay Gould's The Mismeasure of Man.

bpesta regards it as discredited. Gould regarded IQ as discredited. So do many others.
 
Complexity said:
He recommended an article, I'll recommend a book: Stephen Jay Gould's The Mismeasure of Man.
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Gould himself and his work in punctuated equilibrium have not been discredited. The Mismeasure of Man largely has been discredited in the cognitive sciences. Few persons other than laypersons look to it as a scholarly work on the subject of intelligence.

You could have picked a better example to counter Pesta's citation.

AS
 
I've spent some time reviewing some of the critical reactions to The Mismeasure of Man, especially those in psychology. I think it is fair to say that he had a purpose when he wrote the book, that he organized his argument to further that purpose, that those whose views and practices he attacked vehemently disagree with him, and that his writing style makes his works quite accessible to the layman.

I'd say that his book is discredited within the IQ-testing community and those areas of psychology in which that is embedded. This is not a surprise - they are the ones he's calling to account.

I don't know which other fields you regard as "cognitive sciences" and how the book is regarded in those fields.

I do know that I do research in one of the fields regarded as a cognitive science. I regard the characterization of intelligence as one of the great open problems. I don't think the IQ crowd have come close to doing intelligence justice.
 
bpesta22 said:
For those following the other IQ thread-- not so much the main combatants, but anyone on the fence trying to decide what they think about IQ tests:
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In all honesty, I haven't read all of the other IQ thread, but I may have the gist of it (the essence usually repeats).

Here is a short article in Scientific American by Linda Gottfredson. She's a big name in psychometrics, but note that this ain't no psych journal publishing her claims.

I'm citing it here in a new thread because I think its very consistent with what I've been arguing (perhaps showing at least that I'm not making it up), and is a nice lay person's summary of the state of the art regarding g (with all claims passing American Scientists' peer review process).
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Scientific American is not a peer-reviewed journal. What you mean is that the article passed editor-review.

http://www.psych.utoronto.ca/~reingold/courses/intelligence/cache/1198gottfred.html
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The article refers mostly to correlations found between "g" and various other measures of "success". The assertions are unreferenced, making them difficult to evaluate. The statistical references are vague and the statements made in the text are inconsistent with the information presented in the illustration. I'm not saying that any of that makes the information wrong, just that there is no way to independently evaluate the information provided in that article. So it ends up adding nothing to the debate, because whether or not you trust it depends entirely on your perspective prior to reading the article.

What you don't see in the article is discussion of how useful this information is. In medicine, tests are evaluated for usefulness based on likelihood ratios (LR). A test is useful if it makes a difference in the likelihood of a particular diagnosis. For reference, LR's >10 are very useful, 5-10 moderately useful, 2-5 minimally useful, and 1-2 are rarely useful. If you apply these standards to the information presented in the illustration from that article, the majority of the likelihood ratios fall in the 1-2 range - i.e. rarely useful. This means that if you are trying to determine whether or not someone is likely to live in poverty, get divorced or have illegitimate children, IQ testing rarely adds any useful information.

Just something to take into consideration.

Linda
 
AmateurScientist said:
Gould himself and his work in punctuated equilibrium have not been discredited. The Mismeasure of Man largely has been discredited in the cognitive sciences. Few persons other than laypersons look to it as a scholarly work on the subject of intelligence.

You could have picked a better example to counter Pesta's citation.

AS
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But Gould did make valid points about the misuse of IQ tests at Ellis Island in the early 1900s, the testimony of scientists like Goddard before Congress that a majority of certain groups were "feebleminded" and the subsequent passage of immigration quotas for those groups.
 
Linda-- I could be wrong but I thought likelihood ratios are used when the outcome is black or white (you have cancer or you don't; the patient lived or he didn't).

Most of the things that people use IQ to predict seem to fall on a continuum (job performance; grades; income; years education).

One can tell from a validity co-efficient how much variance in y is explained just by knowing x (iq in this case).

Schmidt and Hunter have a classic article showing that-- for job selection-- the incremental validity of IQ for predicting job performance is something like .50. Adding other things to the selection process (reference checks, unstructured interviews, even graphology) adds very little to prediction once IQ is controlled for (the exceptions, iirc, are conscientiousness, structured interviews and work sample tests-- the only selection methods that improve accuracy beyond IQ).

There are also utility formulas where you plug in values based on the cost of admin an IQ test versus its return (the increase in validity, coming just from using a test-- in this case, an IQ test), compounding the return, adjusting for inflation, etc. It's been awhile since I looked at these, but I remember the ROI for using an IQ test in selection is massive.

I posted a smaller version of this in the other thread, but I think it puts things in perspective. Here are some validities for various things:

First, validities of IQ tests:

predicting grades .50
job performance .50
income .33
year's education .55
Speed of neurons firing .33
teenage pregnancy .19
Your IQ given your biological parents' r=.8
Your IQ given your adopted parents' r=.00


Validities of other things:

Nicotine patch and quitting smoking....r=.18

employment interviews predicting job success..r=.20

graphology predicting job success r=.00

Conscientiousness predicting job success r=.30

gender predicting weight of adults in the USA....r=.26

elevation above see level and daily temp in the USA...r = .34

weight and height USA adults r=.44

gender and arm strength for adults...r=.55

prenatal screening of maternal serum to ID down's syndrome, r=.11

test anxiety and grades, r=.17

ECG stress test results and heart disease, r=.22

decreased bone density and risk of hip fracture in women, r = .25

screening mamograms and detection of breast cancer within 2 years, r = .27

pap smear and cervical abnormality, r=.36

accuracy of home pregnancy kit used at home, r=.38

MRI and detection of lymph node metastisis in cervical cancer, r = .55

speed of processing and reasoning ability, r=.55
 
bpesta22 said:
anyone on the fence trying to decide what they think about IQ tests:
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Does the article mention gorillas?

Is there any particular reason you keep trying to bury this inconvienent fact at every turn? If you want to sway fence-sitters in a rational and ethical way, you need to present all of the relevant information.

For instance:

We know that gorillas can delay puberty for up to nine years based solely on social cues. This naturally leads to the question, what effects can purely social cues have on human development? And the answer is... WE DO NOT KNOW.

Therefore, concluding anything about IQ and success in a cultural setting is absolutely unjustifiable. Only dishonest or despicable people would argue for the validity of IQ testing while concealing known sources of error that are larger than the effects they claim to be measuring.

The fact that there are a lot of people pushing this crap is really no more relevant than the fact that there are a lot of people pushing religious crap.

Psychometrics cannot measure IQ separate from cultural influence. Ergo, it is at best useful for determining gross defencies. Its use in any other arena is simply a way to reinforce cultural prejudices.
 
AmateurScientist said:
Hmmm...I smell a political agenda in your criticisms.
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Yes, there is a political agenda here. It is the political agenda of "fairness." It is the political agenda of not allowing cultural prejudices to be supported by culturally prejuiced data.

You also lack the credentials to go toe to toe with Pesta intelligently on the subject, as far as I can tell.
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I cannot comment on intelligently; but perhaps ethically also matters to you. Bpesta, along with the entire psychometric industry, simply ignores data that destroys their mythology.

Compare Bpesta's defense to the defense of lie-detector testing. Surely the correlations between guilty tests and guilty verdicts is reasonably high. Police everywhere swear by them, and there is an entire industry that publishes papers, research, and pretty graphs showing their validity.

Does any of that, even for a second, convince you that the electrical resistance of the skin is a clear window into the mind?

We know about gorillas, no matter how much the industry would like to ignore it. We know about racism, no matter how much some people would like to pretend it does not exist or has no effect. The only number Bpesta presented that means anything is the correlation of IQ with adopted/biological parents. And notice he chose to bury that number under a welter of culturally based metrics. Why do you suppose that is? Does one need outstanding intellectual credentials to spot a pig in a poke?
 
Yahzi said:
Only dishonest or despicable people would argue for the validity of IQ testing while concealing known sources of error that are larger than the effects they claim to be measuring.

The fact that there are a lot of people pushing this crap is really no more relevant than the fact that there are a lot of people pushing religious crap.
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Can we discuss/debate the ideas rather than try to dissuade people from considering point of views by using words like "dishonest", "despicable", "crap", and "religious crap"? I think it detracts rather than adds to the discussion.
 
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