Uhuh.... so this line it's crazy, right?
It's really strange you concede that we have no theory and hence no way of verifying whether an IQ score is a valid and reliable measure of the thing we have no theory of... and yet, you say it is a "proxy for intelligence"
The entire edifice of research which makes these claims is a product of a pseudoscientific use of statistics by amateur statisticians. The vast majority of the results you think exist in the literature are frauds, and often egregious ones at that.
A human being is one of the most complex systems known to exist in nature, and the frauds in psychometrics are very far away from being up to the task of studying them. The greatest minds in applied sciences, matehmatics and statistics would largely throw up their hands at the job of measuring "intelligence" --- that some fools havent, is no good thing.
> The entire edifice of research which makes these claims is a product of a pseudoscientific use of statistics by amateur statisticians.
That's bollocks. It's just a topic that's too complex. Unfortunately, everybody likes it and draws conclusions from it. Even the HR department. If you would say we should ignore IQ measurements in society, I would agree. But it's not pseudo-scientific use of statistics. Nor all done by amateurs. It might even be more scientific than string theory or dark matter.
None have PhDs in statistics. They're all people who got into psychology and were given GUIs by the maths department. Their papers are a symptom of what happens when you press the "ANONVA" button and print the results.
The entire field is an egregious testament to pseudo-intellectual pseudoscience. It's shocking.
There's nothing there. It's unfathomably bad.
A lot of psychology is bad research. There's a reason there's a reproduction crisis. Statisticians are to blame for that, too. They've been teaching and using NHST, even though all arguments point away from it.
But statisticians can't fix a bad design, because they rarely know the factors involved, and they can't fix errors in the methods, because they've got no idea about the subject matter. The statistician in your argument comes across as some kind of totem.
> There's nothing there.
There's something there, but since we don't know what, it's best to take it with a grain of salt. However, if even the bloody HR department looks at IQ scores, it gets a lot of attention. And one explanation is that it predicts better than nothing. If you have to choose between two candidates, and one has an IQ of 80 and the other of 120, you know who (on average) who fits best.
A score of 80 suggests a possible clinical issue with mental retardation. Few such people apply to roles who compete with people at average or above scores.
What is much more the case is people 95-145 "competing" with each other based, effectively, on what star sign they have.
The test probably breaks down at some level since it is hard to test higher intelligence, but it seems to me like it is still valid below about 120 IQ.
Something having an objective measure or not does not invalidate it.
But in any case, what we're talking about is the meter-ruler called "IQ" and its use by the most batshit HRish elements of soceity, and the most pseudo-scientific elements of psychology.
In a world where major employers are using IQ to guide their hiring practices, we're not talking about a quiz on the back of cosmo.
We're talking about a world where business (, uni,...) has outsourced its obligations to fairly consider the merits of individuals to the cult of psychometricians extremely happy to provide astrological justifications for ruining people's lives.
An entire medical establishment has been created by the IQ test, which exists across (at least the west) as a filter on entrants. What strange, bizarre, and often poorly sutied creatures have found themsleves in positions within this establishment?
When one looks around at the society the IQ test has created, one should be aghast. Why, so often, are nurses better than doctors? (etc. etc.)
What the evidence says is that IQ isn't the only factor, just as height isn't the only factor for NBA players. But just like height, IQ makes things a lot easier.