> But you don't need a standardized test to see those differences.
There is also no need to use a thermometer in laboratory work - we're all equipped with fingers. At least ten measurements' worth, at that.
Indirect measures are useful.
Want to determine which teenagers would make decent electrical engineers? Instead of $500 worth of IQ test (proper IQ tests are administered by private psychologists, who do not work for free) one can use $150,000 worth of college/trial-by-ordeal - a poorer measure of general intelligence, overall. Yet it continues to be the only allowed measure, because IQ tests are Officially Evil.
> there is very little difference between an IQ of 120 and an IQ of 130
On what basis do you say this?
> If all IQ is good for is telling the difference between the very intelligent and the learning disabled
I agree with you that intelligence does exist and it needs to be measured. Measured by the completion of medical school/college, by whatever heavily IQ-correlated traits that investors look at or by a wide variety of indirect measurements or proxy tests.
Intelligence should not by measured by a standardized test. Standardized tests simply do not have a history of predicting success at anything on a micro level. If they did, people would use them. It would be trivial for large employers to pay $500 per employee to have an IQ test taken. And it isn't illegal for them to do so. From the court decision:
"Nothing in the Act precludes the use of testing or measuring procedures; obviously they are useful. What Congress has forbidden is giving these devices and mechanisms controlling force unless they are demonstrably a reasonable measure of job performance."
The law doesn't say that you can't use IQ tests for anything of economic importance. It says that you can't use them to discriminate. Do you think Google could show that a high score on a general intelligence test bears a demonstrable relationship to successful performance as a software engineer? And if it doesn't...then what good are the test scores?
It is possible that there is a great conspiracy against IQ tests. They could be the best measurement of intelligence, but people just don't like them. It's also very possible that the test scores aren't used in society because are relatively meaningless.
> Standardized tests simply do not have a history of predicting success at anything on a micro level.
This is empirically false. Read about the Longitudinal Study of Youth. Children took tests, grew up, lived their lives. You cannot argue the data out of existence.
> The law doesn't say that you can't use IQ tests for anything of economic importance. It says that you can't use them to discriminate.
There are many practices which are not illegal per se, but put you at dire financial risk liability-wise.
Read about the actual consequences of the precedent set by the Griggs v. Duke Power Co. decision. Talk to a lawyer about whether it can ever be safe to include a traditional IQ test in your company's hiring process. The problems involved in demonstrating "non-discriminatory intent" and "performance applicability" are insurmountable. Unless you have extraordinarily deep pockets, the sheer expense (not to mention PR debacle) of fighting such a lawsuit will sink you before you are at any risk of overturning the precedent.
> It's also very possible that the test scores aren't used in society because are relatively meaningless.
Once again, the falsehood of this statement can be uncovered by anyone who cares to look. We aren't talking about an organized conspiracy here - only a generation's worth of toxic political correctness.
It absolutely is used. We are simply forced to measure it through indirect means, given that IQ tests are verboten.
> Does anyone even know their surgeon's IQ?
Medical school is (perhaps above all) a proxy IQ test.
> Investors don't seem to care about IQ at all.
They are quite interested in heavily IQ-correlated traits.
> If it could reliably predict anything, don't you think more people would ask about it?
U.S. law de-facto prohibits the use of IQ tests for anything of economic importance: http://caselaw.lp.findlaw.com/scripts/getcase.pl?court=US...
> But you don't need a standardized test to see those differences.
There is also no need to use a thermometer in laboratory work - we're all equipped with fingers. At least ten measurements' worth, at that.
Indirect measures are useful.
Want to determine which teenagers would make decent electrical engineers? Instead of $500 worth of IQ test (proper IQ tests are administered by private psychologists, who do not work for free) one can use $150,000 worth of college/trial-by-ordeal - a poorer measure of general intelligence, overall. Yet it continues to be the only allowed measure, because IQ tests are Officially Evil.
> there is very little difference between an IQ of 120 and an IQ of 130
On what basis do you say this?
> If all IQ is good for is telling the difference between the very intelligent and the learning disabled
This is merely its last permitted use.