4 ms·

AFQT is widely accepted in the psychometric literature to be an IQ test. Military itself believes so: https://www.rand.org/content/dam/rand/pubs/monographs/MG2

• littlestymaar 5y ago
  > For 200 air force enlistees Which means: for the people with a high enough AFQT score, IQ is correlated with AFQT score. This is indeed interesting, but generalizing to the rest of the population is a methodological mistake. Moreover, there is no reason to assume the AFQT score to depend only on genetic factors alone (even if I don't see reasons to assume genetics has no impact on it either). And btw, the study you quote explicitly rules out the conversion done in the book: > no direct one-to-one correspondence AFQT percentile scores and IQ scores can be stated.
  • xyzzyz 5y ago
    > Which means: for the people with a high enough AFQT score, IQ is correlated with AFQT score. This is indeed interesting, but generalizing to the rest of the population is a methodological mistake. No, because everything else we know about IQ, especially the existence of positive manifold, strongly suggest that it will also correlate at lower IQs too. You can’t just say “the study on X has not included Y, therefore we should have absolutely no expectations about any sort of relationship between X and Y”. That’s not how science works. Alas, there have been other studies done, and it turns out that indeed, AFQT/ASVAB score and IQ correlation does in fact extend to areas on the left side of the distribution too, exactly as expected. To reiterate: this correlation exists across entire spectrum, not only among high IQ people. If anything, the correlation at high IQ is lower than expected, because of range restriction effect. > Moreover, there is no reason to assume the AFQT score to depend only on genetic factors alone Fortunately, nobody is claiming that, so you won’t have to put much effort to convince anyone otherwise. > no direct one-to-one correspondence AFQT percentile scores and IQ scores can be stated. It can, though. The problem is that the population of military test takers is not representative of population at large. For one thing, its average intelligence will probably be higher, due to relative scarcity of mentally disabled people. However, if you know the parameters of IQ distribution among military test takers, you can easily convert AFQT/ASVAB to IQ.
    • littlestymaar 5y ago
      > You can’t just say “the study on X has not included Y, therefore we should have absolutely no expectations about any sort of relationship between X and Y”. That’s not how science works. Oh yes it is. Extrapolating outside of study sample is either a scientific rookie mistake or just plain fraud. Doing so in any hard-science topic would earn you an angry comment from your reviewers. > Fortunately, nobody is claiming that, so you won’t have to put much effort to convince anyone otherwise. Oh, and I guess Herrnstein and Murray didn't publish that book? Because they definitely do so in The Bell Curve: They are literally plotting AFQT and SES (their bogus “socioeconomic factors”) against social outcome and since AFQT has a higher correlation than SES, they conclude that genetics must be the decisive factor! And if you read my previous comment, you'd notice that the AFQT -> IQ is only a part of the issue in the Bell Curve, the bigger part being how they assume AFQT -> genetics because they assume AFQT = IQ = g = genetics. (The last steps being an ideological stance, which Herrnstein have been defending for decades prior to the publication of the Bell Curve so it's not really a surprise…)
      • xyzzyz 5y ago
        > Extrapolating outside of study sample is either a scientific rookie mistake or just plain fraud. No, extrapolating outside of study sample is the entire point of doing science. Of what use science would be if we could not do that? Imagine, “no, you can’t say that this vaccine is effective, at best you can say that it was effective in the sample of subjects being included in that study, but you can’t extrapolate that outside the sample, that would be a rookie mistake”. This is, of course, absurd. We do science precisely so that we can make useful predictions in day to day life, outside of studies. > they conclude that genetics must be the decisive factor! I observe a goalpost being shifted, from “genetic factors alone” to them being decisive. I do not accept that. Please, tell me, where they, or anyone else claims that genetic factors alone determine outcomes. > they assume AFQT = IQ = g = genetics I don’t think they do, and it is contradicted by what you wrote in this very comment, where you say they claim genetics is “decisive factor”. This clearly makes no sense under assumption of equality/identity of concepts — you wouldn’t say that A is a “decisive factor” in B, if A and B are the same thing. > ideological stance, which Herrnstein have been defending for decades prior to the publication of the Bell Curve Relationship between g and genetics is an empirical, not purely ideological issue. Hernstein has been saying that g is mostly determined by genes precisely because this is the current state of our scientific knowledge, and has been for decades.