A reader sent the following email:
Good evening, sir! I’ve been enjoying your blog and have a rather random question that I’d love to hear you weigh in on. I recently took a self-scoring IQ test from a book written by the late Victor Serebriakoff. I am curious as to how accurate the scores are. The publishing date was 1996 so I’m wondering how much this would distort the results. A number of online reviewers claim the score they received on this test is identical to the score they received on their WAIS. Would the scores necessarily be grossly inflated? Or could they be relatively accurate? The test consists of 300 questions with subtests for verbal, spatial, and numbers. Just curious to hear your take on it. Thanks for taking the trouble to read this meandering email!
I don’t have a copy of this test so all I can do is provide a meandering speculative reply:
Given Victor’s credentials as the head of Mensa, combined with the fact that the test had 300 questions of diverse type, I would guess it’s a very valid measure of intelligence.
But whether the scores are inflated is hard to say. I’ve seen several self-scoring IQ books in my life and none of them have ever explained how they converted the raw scores into IQs. And in some cases, they don’t even adjust for age, treating all adults as a single age group.
If Victor had done a quality job norming the test, then I’d expect him to have discussed it in the book. If he didn’t, then he may have just used a convenience sample (friends, acquaintances) and since he’s a high IQ man, his circle of acquaintances are likely above average. If so, the test might actually underestimate your intelligence.
On the other hand, the test is over 20 years old, so the Flynn effect might have caused your score to become inflated by as much as 6 points. Although, when tests are normed on the entire country (instead of just the white population) demographic changes can negate or even reverse the Flynn effect.
I also wonder how this test arrived at overall IQ scores since you say it measured several cognitive domains. If it merely averaged your scores on all three domains, it may have underestimated your overall IQ, since for example only 5% of the population maybe smart enough to average in the top 10% across three different abilities, so such people are perhaps in the top 5% (IQ 125+) even though they average in the top 10% (IQ 120+).
A reader sent the following questions by email:
Also, what other traits determine the variation in academic achievement. Achievement and IQ only have a .5 correlation.
Just a hypothetical- what if you come across a vocab word or an information subtest fact a couple days after the test?…
Depends what you mean by academic achievement. If you mean scores on an academic achievement test (which measures your total academic knowledge), the correlation is much higher than 0.5 in the general U.S. population.
If you mean the correlation between IQ and academic success (i.e. school grades, highest level of schooling) then it’s about 0.57 in the general U.S. population, although it used to be 0.7.
The other major trait that predicts academic success is conscientiousness.
Beyond those two major traits are probably a a whole bunch of minor traits, which on their their own explain very little, but collectively explain quite a bit. These might be things like physical heath, conformity, how much your teachers like you, how much you like school, whether you’re a night person or a day person (as commenter Mug of Pee once mentioned) etc.
It’s also worth noting that verbal IQ better predicts academic success than performance IQ, even holding general intelligence constant.
Of course the term “predict” might be a bit of a misnomer. Correlation != causation. There’s evidence that staying in school longer might raise IQ (though it’s unclear if it’s actually raising intelligence itself)
As for your second question, what you know outside the testing room is irrelevant. As David Wechsler noted, the tests are designed to measure your intelligence under a fixed set of standardized conditions. Once you leave that controlled environment, you’ve left the test.
A reader sent the following question by email:
Pumpkin, do most people on processing speed tests go as fast as they possibly can?
Yes, I think they do. Although the term processing speed is a bit of a misnomer. These subtests have among the weakest correlation with chronometric ability. Ironically, it’s the untimed power tests that often enjoy the highest correlation with chronometric ability. People in the field are very familiar with the slow looking nerd who is brilliant at solving really deep problems. Such individuals do relatively poorly on tests of psychometric speed, but extremely well on tests of chronometric speed.
Psychometric speed tests are poor tests of general intelligence, but they seem good for measuring the intelligence of otherwise smart people who just can’t adapt.
I’ve had a couple friends who did well on most g loaded tests, yet I did not consider these friends smart because they couldn’t adapt situations to their advantage in real life. Both of these friends did extremely poorly on the processing speed subtest of the WISC-R.
Pumpkin Person 
Regarding the Serebriakoff test-
Unfortunately the author doesn’t give much explanation for how the test was normed. For some reason the test is heavily weighted on the verbal sub test
Spatial + Math + Verbal (3X)
You then use a conversion scale to find estimated IQ. I’m not sure why it’s weighted so heavily towards Verbal. More g loaded, perhaps?
a yuge advantage of socialism is fewer ugly people having babies.
because without economic inequality sex reverts to the stone age.
bill gates…no chillens…because ridiculously unsexy.
and who knows which is which and who is who?
without economic inequality women don’t need providers, so the sexual market turns into africa’s, not the european stone age
eurpean stone age = africas
African women need providers though, an ugly person like Jacob Zuma can have 20 kids with several women much better looking than him. https://kasidaily.co.za/wp-content/uploads/2018/02/Jacob-Zumas-wife.jpg
I wonder if polygamy is an form of IQ eugenics within SSA, if money and genomic IQ are correlated in SSA.
the modern world is largely the attempt by the high school nerds to get themselves the bitches.
Yikes I just had an argument with a liberal musician about the importance of race. His whole point was basically that race was subjective, which is already obvious. but what I was trying to tell him was that it still matters culturally because race is tied to culture. Essentially race matters because other people think it matters.
Distinctions like this are so subtle it really separates those who are truly intelligent from those who aren’t. Forgive me I’m very drunk.
You sound racist
Someone fucking argue with me, right now!
Would you think third world nations have an strong correlation between neural plasticity during youth and wealth? Or are you too much into the “Reaction norms argument” to think that their pehnotype in youth (creating their environment in a way that only can be done through their phenotype in early age, causing them to be smarter than others in this environment, but only that since they would have not have neural plasticity in 1st world environments) that makes them smarter in third world environments would fail to do so in 1st world environments thanks to the wrong genes?
Also, do you think neural plasticity is mediated by any environments, if so, which?
“Would you think third world nations have an strong correlation between neural plasticity during youth and wealth?”
You may need to rephrase your questons better. I’m not exactly sure what you mean, Neuroplasticity is something that occurs in all human brains, on many levels. The connections between a post a pre-synaptic cell can strengthen or weaken, this is it’s plasticity. There is also compensatory plasticity which is when(as an example) a blind person’s visual cortex structurally changes to perceive non visual information. There is also functional connectivity, which is just how easily different regions of the brain can communicate in variable oscillations. Epigenetics, is a mechanism for plasticity
“Also, do you think neural plasticity is mediated by any environments, if so, which?”
I’d assume variable ones. Then again, prolonged childhood is favored by more stable environments.
Oh shoot. I meant to say: Would you think third world nations have an strong correlation between the age where large amounts of neural plasticity during youth stops (basically prolonged childhood) and wealth?
And so the other question also talks about prolonged childhood, but you answered that one.
King meLo
“Would you think third world nations have an strong correlation between the age where large amounts of neural plasticity during youth stops (basically prolonged childhood) and wealth?”
I don’t believe intelligence has a perfect correlation with wealth. There are studies that indicate synaptic pruning is positively correlated between age of onset in mental puberty and intelligence.
The thing is King meLo , that i want to discover the selection differential or the correlation between IQ expressed in an 1st environment and wealth within the third world, especially Nigeria and India. Becuase that could be used to speculate a lot.
Ah so you’re basically trying to figure out the amount of cultural affect on IQ expression. Or more specifically the IQ of third world elites?
No. What I want to figure out is how large of an percentage of all genomically high iq people are in the upper class, within the third world. Make that into a ratio to see the correlation between genomic iq and wealth within the third world. From that we could also guess the correlation between wealth and iq by comparing it to the west on the same traits.
Puppy how come you never answer any of my questions?
Becuase you dont awnser mine. Karma, biitch!
I scored 123 on Serebriakoff’s test, an average of two tests. My best score is 127. I recently took the RAIT with mensa, and it was so much easier, though not saying I did well enough to pass; hate it when you finish a section fighting nervousness, with uncertainty imprinting a questionable answer in memory, indicating you knew the right one the first time but changed it.
By the way, mensa lets you pass if you score in the 98th percentile of any one of the subtests of the RAIT. Why is that? Regardless of the percentile of the total battery, which presumably reflects the measured IQ. Unfortunately, I haven’t been able to find studies regarding the validity of the RAIT.
That’s interesting about the RAIT. That would be interesting to see how your score lines up with the score you received on the Serebriakoff test. I find this stuff endlessly fascinating
Check this out for info on the RAIT – it’s a sample report: https://www.parinc.com/WebUploads/samplerpts/RAIT%20Sample%20PiC%20Score%20Report.pdf
Lists and explains each section and how things are scored, with, presumably, total battery index being the FSIQ equivalent and total intelligence index being the GAI equivalent. As I said, for some (not so) weird (monetary) reason MENSA takes any one of the indexes (Crystallized, Fluid, Quantitative, Total Intelligence, Total Battery) to qualify someone as “top 2%.” So obviously MENSA is not the society it claims to be.
In both Serebriakoff’s test and the RAIT, I felt the most comfortable on the fluid/spatial section; crystallized intelligence isn’t my strong suit, along with quantitative knowledge. However, I do have to add that after taking Serebriakoff’s test I began studying for the GRE and likely brought my crystallized IQ score up. Though, I know for sure I did not do well on the general knowledge portion – feel like they rely on too many obscure names (I left half blank….) – the other parts I felt pretty confident.
Based on some people’s scores I found online, it seems to me that crystallized intelligence is the most important when it comes to total battery index or total intelligence index – similar to Serebriakoff’s.
Well, will know soon, but I wouldn’t be surprised if I scored somewhere close to 127. Like I said, most significant change for me is having gone through GRE verbal study.
Billy
Thank you for all that info! Very curious to hear where you fell on the RIAT. I hit 126 on Tests A and B of the Serebriakoff test, but my area of strength was in the Verbal. This likely gave me a boost since his test is weighted heavily on Verbal. I’m not in a position to take a “true” IQ test at the moment so I’m in search of a ballpark estimate. Thanks again
What’s the use of a processing speed test? Maybe that it “creates” time for you or something?
Apparently the Flynn Effect reverses from IQ 110.