Monday 1 August 2016

The g nexus: Detterman detail

 

It has been very hard getting intelligence research results out to the public. All researchers, whatever their subject, tend encounter the same problem: they get excited about findings which the general public don’t find interesting, or don’t understand. Researchers complain that their subject is ignored, misrepresented and on the odd occasion that it is noticed at all, the treatment is superficial, the selection of supposed experts absurd, the main points mangled

Intelligence research has experienced all of the above, and more. Researchers get thrown out of the university posts, harassed with legal challenges and cumbersome investigations, and systematically avoided by publishers and research funding bodies whenever the results are considered unwelcome.

One researcher who was given the full “ignoral” was Chris Brand. Before being consigned to the outer darkness he wrote a chapter in 1987 entitled “The importance of general intelligence” and Arthur Jensen quoted his summary in Table 9.3 (page 300) of his book “The g factor” in 1998. Brand had also written a book entitled “The g factor” in 1996, which was to have been published by Wiley, who then chose to “de-publish” it.

The list of positive and negative correlations with intelligence that Doug Detterman showed in his lecture is his updated version of Brand’s 1987 original, and as intelligence research flourishes it will continue to be updated. Any slide has to be a summary, but some of the entries were a bit too terse. Doug has provided some very brief explanations of the items readers found confusing.

“Abnormal is normal” means that the same genes that cause normal processes are the same ones involved in what we call "abnormal" conditions.  In other words, abnormality is simply the extremes of normality.

“World conservatism” refers to a score on a test of world conservatism and can be read as conservative in the common political sense of the word.

“Drop out rates” are, of course, negatively correlated with intelligence.  If  I said that, then what I should have said is that educational completion levels are positively correlated with intelligence.

For the background detail, Doug has provided a chapter he is working on.

https://drive.google.com/file/d/0B3c4TxciNeJZRGM1X0V3YjJGc1k/view?usp=sharing

18 comments:

  1. Neuroticism would surely mean something like emotional INstability.

    Anyway, the Nazi IQ figures reminded me of a webpage that popped up on my screen recently listing the IQs of American presidents - sometimes to five figure accuracy. Obviously those would all, or nearly all, be mere fiction.

    I believe that the only measured IQ for a President that I've seen was for JFK - it was 119, or 117; something like that. I did once read Steve Sailer make the point that you can probably get a decent estimate of IQ from US armed forces officers' tests. He did the sums for GW Bush and John Kerry; the answers were pretty similar, putting Bush slightly higher. The absolute numbers were, to the best of my rather feeble memory, somewhere in the low 120s.

    My question for you, doc, is whether any other factual IQ scores are public knowledge for prominent US politicians?

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    1. You can get partial estimates by looking at the grade points required to get into the universities they attended, though favouritism or quotas can distort that picture. The Bush/Kerry comparison was interesting. I find that audiences otherwise skeptical about assessing intelligence have no difficulty when asked to assess Bush's mental ability. No paper trail on Obama, apparently.
      It is a relevant question, particularly when they are asked to pronounce on highly technical issues.

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  2. Page 11 - apparently the average IQ of Oxford maths faculty, the highest scoring group among professors there, is 130 (the same as the average maths PhD in the US per Hsu's conversion of GRE scores). The study was in the 1960s but I'd have still reckoned that STEM faculty at Oxbridge would be at least +3 standard deviations - in the case of maths/physics, more like +4 standard deviations above the mean.

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    1. It may perhaps have been partly a definitional problem. In the British sense of the word there probably wouldn't have been any science "professors" in Oxford between the ages of 25 and 34. So someone is presumably applying "professors" in an American sense to some bunch of Oxford academics defined I-know-not-how.

      Still, I agree that 130 seems low: do we know which test was used, its SD, etc?

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    2. Individuals would have been, but 2 sigma as a group average is pretty good. I don't have the sample size, nor know how representative it was of the faculty as a whole. "No one gets round sampling theory, not even the Spanish Inquisition".

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    3. Or are we seeing the Flynn Effect? Or possibly that the clever mathematicians would have been at Cambridge?

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    4. Brightest "mathmos" probably at Trinity College Cambridge.

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  3. If we pretend that the SD was 15 and the distribution was Normal, this means that over the course of a few years a non-negligible number of Oxford maths dons wouldn't have got into the top two streams at my secondary school (requirement 118, or so we were told). That seems most unlikely to me.

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    1. On reflection: sampling error. How do you get a bunch of adults to agree to take a test when it's just a nuisance to them?

      Unless you offer a decent bottle of claret for each point scored, why would anyone bother?

      I've done two IQ tests: one was to determine my further schooling, the other to determine whether Megacorp would offer me a job. I was subject to incentives that would have been absent for the mathematicians.

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    2. elijahlarmstrong3 August 2016 at 05:55

      How did you score?

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    3. Well, presumably. I got what I was after.

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  4. On the subject of JFK: a friend of mine met him when he was a senator. Said he had considerable charm, wasn't remotely clever, but was capable of attracting clever chaps into his employment. I suppose having mountains of money helps with that.

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  5. elijahlarmstrong2 August 2016 at 21:10

    Detterman's chapter makes almost no attempt to ascertain causality between IQ and various outcomes –– just listing various correlations –– which is disappointing. Also, I don't know what adaptive behavior scales correlate highly with IQ. Mercer's do not. Do the Vineland?

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  6. Vineland has a very restricted range.

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    1. elijahlarmstrong5 August 2016 at 21:22

      What adaptive tests do correlate strongly with IQ? I think ETS developed one that did. There was one in the Philippines that was so-so.

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  7. Actually doc, there's a question begging to be asked. Have people studied the effect of motivation of IQ test participants? Maybe not a bottle of decent claret per point but, say, an aniseed ball per point for the 11-year olds, and some equivalent for the older.

    No, no; not an aniseed ball. A smarty.

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    1. elijahlarmstrong4 August 2016 at 23:45

      Yes, and it's strong. Cf. Lovaglia et al. (1998) on priming and IQ tests, and Duckworth et al. (2012) on motivational effects.

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    2. Doesn't the strength of this effect actually make it all the more surprising that iq tests have strong predictive validity when not everybody tries their best?

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