A reader asked which was the better test. I once asked J. Philippe Rushton which IQ test he would put more trust in if they gave different results: The Raven or the Wechsler.
“They’re both excellent tests,” he gushed, but the problem with the Wechsler he felt, was that there’s a lot more room for scoring error because the examiner has to time you to the second on certain puzzles, and various verbal questions require subjective scoring, so in a case where the two tests disagreed, Rushton placed his vote with the Raven.
However the Wechsler is probably much more g loaded, and recent editions of the Wechsler include a Matrix reasoning subtest, so now the Raven has been reduced to just another Wechsler test.
The Wechsler probably also has more predictive validity, not just because it’s more g loaded but because it measures non-g abilities that are useful in life like verbal skill, spatial ability, processing speed, memory, and social understanding.
One of the great disappointments for psychometrics was discovering that the Raven was not the culture-fair test so many psychologists had hoped. In fact it shows some of the largest Flynn effects ever recorded, though this doesn’t necessarily prove it’s the most culturally biased, as the Flynn effect has a biological component (nutrition increasing brain size which might in turn be increasing IQ) and the biggest Raven Flynn Effects were in countries like Holland, where people have been getting taller so rapidly that brain size is likely exploding.
Nonetheless IQ gains of 7 points per decade are unlikely to be entirely caused by exploding brain size so we’re forced to admit the Raven is sensitive to something changing in the culture, and thus is not culture fair.
People think culture bias means the Raven must be measuring some kind of knowledge or skill, but I suspect the culture bias is more subtle. When Rushton administered the Raven to a bunch of gypsy adults they had shockingly low scores (only IQ 70 on average), far lower than the IQ 85 that had been reported for gypsy children.
My guess is dropping out of school made the gypsies intellectually lazy and so their Raven scores (though not real intelligence) declined rapidly with age, relative to the white reference group, most of whom stayed in school.
Because so many gypsies complained that the test was giving them a headache, it was clear their minds weren’t used to working hard intellectually. For me the lesson was a true culture reduced test needs to be “fun” like some of the hard-core Performance subtests on the Wechsler, not hard work like the Raven.
The fact that some studies show IQ declining when kids go on summer vacation is more evidence for the intellectual lazy factor.
The other day I was at a bar when a woman confronted me. “You don’t remember me, do you. Oh how could you, you were just a teenager, but you gave me a test!” she reminded me.
It took me a while but I remembered she was the delinquent older sister of a childhood friend who had had shocked her upper middle class family by running away from home to dabble in drugs and prostitution. In high school, my friend and I would sneak downtown to stay at her apartment.
“I just wanted to give you a hug” she said sweetly, “because of you I ended up getting my college diploma!”
“What did I do?” I asked puzzled.
“You always used to give me those tests,” she explained, referring to some Raven items I would ask her to solve when I first learned about the test. “So when it came to taking the exam to get into college, I was totally prepared.” (Unlike our universities, Canadian colleges use entrance exams because many applicants are high school dropouts who lack basic skills)
Apparently I had cured her intellectual laziness.
Pumpkin Person 
a canadian “college” equates to an american community college apparently.
flushton told me that he preferred thick toilet paper. he said this with a shit eating grin on his face. “what?” i said. he said, “that was some good shit,” he said.
No big difference for me.
Ravens 115
Wechsler 113
more interested in what 130 in figure weights is good for.
and 135 on the stroop task.
Processing speed seems to be a motor vision pattern task.
What’s your age bracket, out of curiosity? I really like these chance meetings, I often think about how human lives affect each other.
Thirties
Incredible how someone could become so twisted and warped so young.
Its clear pumpkins encounter with this woman ruined her life and forced her into prostitution and drugs. Pumpkin isn’t telling the whole story.
Pumpkin was actually a drug dealer when he was younger. The ‘test’ he gave her was testosterone, among other recreational and hardcore drugs. Its well known.
How coincidental isn’t it that everyone that encounters pumpkin has their life ruined.
Take me, for example. Before I found this blog I was a well adjusted employed and respectable person.
You are kidding!
““They’re both excellent tests,” he gushed, but the problem with the Wechsler he felt, was that there’s a lot more room for scoring error because the examiner has to time you to the second on certain puzzles, and various verbal questions require subjective scoring, so in a case where the two tests disagreed, Rushton placed his vote with the Raven.”
No they’re not. They still fall prey to test construction, calibrating tests against social class though item analysis and selection.
“The Wechsler probably also has more predictive validity, not just because it’s more g loaded but because it measures non-g abilities that are useful in life like verbal skill, spatial ability, processing speed, memory, and social understanding”
How? G-loadedness is sociocognitive-affective preparedness.
“One of the great disappointments for psychometrics was discovering that the Raven was not the culture-fair test so many psychologists had hoped. In fact it shows some of the largest Flynn effects ever recorded, though this doesn’t necessarily prove it’s the most culturally biased”
It necessarily does. The Raven is the most enculturated test, due to hide energy structure.
“as the Flynn effect has a biological component (nutrition increasing brain size which might in turn be increasing IQ) and the biggest Raven Flynn Effects were in countries like Holland, where people have been getting taller so rapidly that brain size is likely exploding.”
The Flynn Effect is caused by the swelling of the middle class, which, again, lends credence to the sociocognitive-affective nexus being the source of variance in test scores.
“so we’re forced to admit the Raven is sensitive to something changing in the culture, and thus is not culture fair.”
Because contrary to popular belief, even though it’s ‘just puzzles’ the psychological and cultural tools used to do well on the test are concentrated more in the middle class. So the middle class has swelled, test scores got better which is what we call the Flynn effect.
“My guess is dropping out of school made the gypsies intellectually lazy and so their Raven scores (though not real intelligence) declined rapidly with age, relative to the white reference group, most of whom stayed in school.”
I’ve shown evidence that motivation and school attendance influences Raven scores.
Reading was the greatest predictor of performance Raven’s, despite controlling for age and sex. Attendance was also strongly correlated with Raven’s performance. These findings suggest that reading, or pattern recognition, could be fundamentally affecting the way an individual problem solves or learns to learn, and is somehow tapping into ‘g’. Presumably the only way to learn to read is through schooling. It is, therefore, essential that children are exposed to formal education, have the motivation to go/stay in school, and are exposed to consistent, quality training in order to develop the skills associated with improved performance. (pg. 83)
http://digitalrepository.unm.edu/cgi/viewcontent.cgi?article=1016&context=anth_etds
Many assumptions go into these tests. And if you just think about how they’re constructed then you’ll see the source of variance in test scores is due to that, along with the sociocognitive-affective nexus which differentially prepares individuals for test-taking, since the psychological and cultural tools needed to excel are concentrated in the middle class, so in effect IQ tests “cultural distance” from the middle class. Even the paper I cited above lends credence to that, even on ‘nonverbal’ tests which supposedly are true measures of ‘g’ (as Jensen wrongly noted).
I’m hovering between Pumpkin’s opinion that HBD does exist but the differences are smaller than otherwise believed to me, or that intelligence is entirely based upon physiological differences such as height and head size which comes down to the individual’s genetics.
Most likely different races have different average heights/brain-size/temperament, meaning different intelligence but not caused by being a certain race.
Height and head size are physical not physiological. The point is, even with so-called physiological measures, you need to show which came first and it could be confounded by social class (not the abstract ‘SES’). Intelligence is also hard to, if not impossible, to define etc.
Either way Rushton was wrong and he clearly had never read critiques on the Raven.
The “critques” of the raven are incoherent garbage, only somebody that does not understand IQ test construction would promote it.
“intelligence” in the sense used by psychologists means g. g is the “explanation” for why tests correlate. it is a statistical fact that they do. “what is g really?” is the question. this is what intelligence researches should be trying to discover. but maybe they aren’t trying very hard or maybe they’re just dumb.
steve shoe describes the correlation of all cognitive tests, even if small, “highly non-trivial”. “cognitive” merely means involving thought. so free throw shooting doesn’t count as a cognitive test? maybe.
it is trivial that the SAT and ACT and the wechsler verbal correlate, but non-trivial that SAT scores correlate with object assembly or picture completion.
i have mentioned it before but rr needs to be reminded. it will be his poison frog.
the most reliable, most g-loaded, and most heritable subtests of the wechsler are its most culturally loaded subtests even correcting for reliability. this is itself “highly non-trivial”. “culturally loaded” is defined precisely in the article.
https://blogs.scientificamerican.com/beautiful-minds/the-heritability-of-intelligence-not-what-you-think/
if only rr started eating centipedes he could secret his own poison.
the most reliable, most g-loaded, and most heritable subtests of the wechsler are its most culturally loaded subtests
Jensen dismissed this as just an artifact of culture loaded tests being more complex. Also, in the bouchard study performance IQ was more heritable than verbal. While the bouchard study had problems, it didnt suffer from the equal environment assumption like other heritability studies
Adding perspective Mugabe’s point: It’s quite hilarious that Richardson or whoever had to make a up a new word for “culture/feedbackloop” it just goes to show the level of mental masturbation, cognitive dissonance, and semantic obfuscation that was going on his head when he was writing this trash.
“this is what intelligence researches should be trying to discover. but maybe they aren’t trying very hard or maybe they’re just dumb.”
The biological mechanisms that govern g across mammalian and bird species are known as:
“The best fit between brain traits and degrees of intelligence among mammals is reached by a combination of the number of cortical neurons, neuron packing density, interneuronal distance and axonal conduction velocity—factors that determine general information processing capacity (IPC), as reflected by general intelligence. The highest IPC is found in humans, followed by the great apes, Old World and New World monkeys. The IPC of cetaceans and elephants is much lower because of a thin cortex, low neuron packing density and low axonal conduction velocity. By contrast, corvid and psittacid birds have very small and densely packed pallial neurons and relatively many neurons, which, despite very small brain volumes, might explain their high intelligence. The evolution of a syntactical and grammatical language in humans most probably has served as an additional intelligence amplifier, which may have happened in songbirds and psittacids in a convergent manner.”
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4685590/
go back to china.
Melo,
“The “critques” of the raven are incoherent garbage, only somebody that does not understand IQ test construction would promote it.”
No they’re really not. Stating that Richardson does not understand test construction is pretty funny, seeing as he’s been writing about it for 40 years.
“It’s quite hilarious that Richardson or whoever had to make a up a new word for “culture/feedbackloop” it just goes to show the level of mental masturbation, cognitive dissonance, and semantic obfuscation that was going on his head when he was writing this trash.”
Term* and it’s the sociocognitive affective preparedness nexus for future reference. Please, do tell how it is ‘cognitive dissonance’. I’m sure you can write Richardson an email and tell him this yourself.
k.richardson@mac.com
He answers emails and you can even contact him on Twitter. Please do this, I’d like to see his response. (Don’t call appeal to authority, just a simple suggestion.)
And he is a developmental systems theorist, so he knows about ‘culture/feedbackloop’.
Mugabe,
“g is the “explanation” for why tests correlate. it is a statistical fact that they do.”
RIght, and tests intercorrelate. Why? Because the new tests are ‘validated’ off of the old ones! They also correlate with other measures of academic achievement because they are different versions of the same test. Relevant:
So what is common may be ‘built in’ by the methods of test construction, rather than captured, as it were, from nature. Jensen (1980) himself has noted how in ‘the best standardized tests . . . every item is carefully edited and selected on the basis of technical procedures known as “item analysis”, based on tryouts of the items on . . . the test’s target population’ (p. 145). Terman (1916) described how items on the Stanford–Binet test were painstakingly selected or deselected according to their agreement with performance on the scale as a whole, so creating the appearance of measuring ‘one massive common factor’ (Butcher, 1968, p. 221). Most other tests have followed the Stanford–Binet in this regard (and, indeed are usually ‘validated’ by their level of agreement with it; Anastasi, 1990).
[…]
It seems at least as plausible to argue that the ‘common factor’ being measured in IQ tests is actually the nexus of sociocognitive and affective preparedness factors described above. So when g is statistically abstracted from test performances, it is simply purifying this nexus (partialling out extraneous sources of variance). This is why correlates of g with other subjectively assumed criteria of ‘intelligence’ tend to be higher than those of raw IQ scores.
Click to access 3398d781543cd0edcf51f181074f4c3ff35b.pdf
“but non-trivial that SAT scores correlate with object assembly or picture completion”
What’s the correlation?
It’s also worth noting that there are very few, truly additive Mendelian loci for complex traits:
http://sci-hub.tw/10.2307/3833170
And Mugabe they’re just dumb, using outdated models of the genes and assuming additivity for complex traits when few complex traits are additive and Mendelian!
Melo, cool comparison between-species, nothing about individual differences in humans. The BG model is predicated on the additivity of complex traits, and that so few Mendelian traits are complex, ‘intelligence’ probably is not additive. Extensive arguments against this assertion have been made, re the ‘addiditivity’ of genes.
Also one more thing, remember that Raven’s items are chosen based on ‘intuition’ and what the constructor ‘thinks’ is hard, then they are ‘analyzed’ and excised if they don’t conform to normality. Just to remind you that item selection/analysis has no cognitive theory backing it. It’s literally arbitrary. Relevant:
McNemar: “One who would construct a test for intellectual capacity has two possible methods of handling the problem of sex differences.
1 He may assume that all the sex differences yielded by his test items are about equally indicative of sex differences in native ability.
2 He may proceed on the hypothesis that large sex differences on items of the Binet type are likely to be factitious in the sense that they reflect sex differences in experience or training. To the extent that this assumption is valid, he will be justified in eliminating from his battery test items which yield large sex differences.
The authors of the New Revision have chosen the second of these alternatives and sought to avoid using test items showing large differences in percents passing.” (McNemar 1942:56)
Richardson: This is, of course, a clear admission of the subjectivity of such assumptions: while ‘preferring’ to see sex differences as undesirable artefacts of test composition, other differences between groups or individuals, such as different social classes or, at various times, different ‘races’, are seen as ones ‘truly’ existing in nature. Yet these, too, could be eliminated or exaggerated by exactly the same process of assumption and manipulation of test composition
How arbitrary is that? And do note that this selection/analysis of items for these tests have not changed and these arbitrary rules go for any and all tests, even the so-called ‘culture-free’ tests.
Also:
Suffice it to say that investigators have simply made certain assumptions about‘what to expect’ in the patterns of scores, and adjusted their analytical equations accordingly: not surprisingly, that pattern emerges!
Whoa. They’re wizards!
peepee literally can’t stop lying.
article oct 2013.
densen dead oct 2012.
so densen must have “dismissed” by seance.
[redacted by pp, feb 13, 2017]
The article may have been written after Jensen died, but Jensen’s been rebutting that same tired talking point since the 1970s.
Mug of Pee thinks it’s an original argument. LOL!
“seeing as he’s been writing about it for 40 years.”
LOLOLOL, that idiot has been writing about a topic he knows nothing about for 40 years? What a mess XD
“I’m sure you can write Richardson an email and tell him this yourself.”
Tell him what exactly? That he doesn’t know what test specification, or repeatibility are? This is how stupid this guy is, he says ” it a dynamic system with feedback loops, you can’t reduce to just it’s singular parts, but then places higher importance on culture. What a fucking hypocrite.
Fuck it why don’t you just quote all the shit I just talked and send it to him. He will not have a cogent response, because the fact that he is even arguing what he is, is evidence of his intellectual inferiority. I found out it was a feedback loop when I was 17. It took you twice as long and him 40 fucking years.
“nothing about individual differences in humans.”
Doesn’t matter. It’s more than likely the same in human and PFIT demonstrates this.
“It’s literally arbitrary.”
No it’s not, otherwise you would have gotten a better score 😉
Objective normality, not subjective. Still never answered my questions. Still wrong as usual.
“LOLOLOL, that idiot has been writing about a topic he knows nothing about for 40 years? What a mess XD”
Funny.
“Tell him what exactly? That he doesn’t know what test specification, or repeatibility are? This is how stupid this guy is, he says ” it a dynamic system with feedback loops, you can’t reduce to just it’s singular parts, but then places higher importance on culture. What a fucking hypocrite.”
No he doesn’t. The argument ties back to how presuppositions from test constructors make the test in effect a test of social class due to the knowledge on them (test constructors also come from a narrow social class which, too, affects this), and so since it tests a certain class-specific knowledge then those who are not part of said class are not prepared in the same ways as people of higher classes. It’s not hypocritical at all.
You can just shoot him an email and explain your grievances and see what he says. I’d love to see his response. I tell this to people on Twitter who shit-talk his work and they never do it. Will you? His email is above.
“Doesn’t matter. It’s more than likely the same in human and PFIT demonstrates this.”
Yea, I’ll return to P-FIT soon, but are there genes implicated in this phenomenon?
“No it’s not, otherwise you would have gotten a better score”
What do I have to do with this discussion? Nothing at all.
“Objective normality, not subjective. Still never answered my questions. Still wrong as usual.”
Melo is right, everyone else is wrong 100 percent—Melo, 2/13/2018
Yes, normality as in normal curve. Whatever does not fit it they excise from the test, making it inherently subjective to the presuppositions from the constructors.
“class-specific knowledge”
IQ tests do not contain that level of bias, the only bias that exists are literally between cultures not between social classes.
Fuck it, mamma didn’t raise no bitch.
“Yea, I’ll return to P-FIT soon, but are there genes implicated in this phenomenon?”
Not sure, ill look into it.
“Melo is right, everyone else is wrong 100 percent—Melo, 2/13/2018”
RR, you and I agree on a lot. I just don’t think culture is anymore the answer than genetics. I just get frustrated at the ad nauseam.
“Yes, normality as in normal curve. Whatever does not fit it they excise from the test, making it inherently subjective to the presuppositions from the constructors.”
No normality(not a bellcurve) as in they devised items that reflected Darwinian mental traits and then tested it on populations. It’s only slightly subjective and not enough to be considered an opinion or a bias.
.64 vs .71 isn’t significant for 48 twins [redacted by pp, feb 14, 2018]
Statistical insignificance just means we can’t be overly confident in the result, but the result still points to performance IQ being more heritable. At least in this study.
[redacted by pp, feb 14, 2018]
densen just made up shit, so he could keep lying.
how did he propose that those tests which are altered from one country to another are more complex than those which aren’t? how did he measure complex?
answer: he didn’t mean anything. he didn’t measure it. he was a retarded psychology professor jiving.
Think about all the steps the brain must go through to learn a new word or fact. You have to pay attention to what you hear. Understand it. Remember it. Then associate it with what you hear in another context, and make an inference. Every time you learn a new word it’s like solving 5 different problems, making vocabulary tests incredibly efficient measures of intelligence.
sociocognitive-affective nexus
11 syllables when you could just say “jive”.
Nope. Nice try though.
black people are always talking to themselves. they can’t stop jiving.
OK? What’s that have to do with my comment?
Admit it race, you dont like the tests because the authors are black.
Because the brain is a network of subnetworks there is no one fluid intelligence, there is no one crystalized intelligence. There are different ways to manipulate information and to retrieve information. Because they are located in different areas of the brain.
I wrote an essay about science in 5th grade and I went to a science magnet middle school. My social economic status was lower middle class. My mom would buy me books and I read at the library a lot. I drew inventions and the like. My mom had friends that would donate money to send me and my two siblings to bible camp. Spent two years I foster homes after a fight with my brother. My mom is not normal, she does not know how to have conversations. I liked to play with legos, we had a windows 98 computer in the kitchen. And a Nintendo GameCube in the living room. I would watch the history channel and Anime on cartoon network.
In high school I acted like my mom, I did not talk to people, had no ideas what was happening. Just did my homework and was egoless. Never asserted myself. Had no social awareness. Was not opinionated. It was like I was blank. My mom is blank.
I could have learned more if I had more social awareness.
Pumpkin said the wisc3 and wais4 measured different brain areas.
That could mean something in relation to my fluid and crystalized intelligence.
Inability to express some brain areas and overexpress others.
“more g loaded but because it measures non-g abilities that are useful in life like verbal skill, spatial ability, processing speed, memory, and social understanding.”
What non-g abilities mean concretly ?
g is just whatever is causing all cognitive abilities to positively correlate, so non-g abilities are just whatever source of variance is left over after g is accounted for such as verbal, spatial, mathematical, memory or social talents.
‘g’ variance is the sociocognitive-affective preparedness nexus.
RR aren’t you doing the same thing you accuse HBDers of doing: assuming correlation equals causation? Assuming that just because g is correlated with social class, it’s caused by social class?
Not really. IQ tests correlate with social class due to test construction and because they’re constructed by people from a narrow social class. Therefore, since lower class people are more likely to be affected by this nexus, they will score lower because they’re differentially prepared for the tests compared to middle and upper class people who have the cultural and psychological tools needed to score well.
What do you think of Lev Vygotsky?
RR
Is my g 130 because my mom bought me a lot of toys, took me to the library when young and had me go to magnet schools? I talked to a social worker recently and I got validation that I had episodes of depersonalization for 6-8 years before I took the IQ test.
Pumpkin, there is a small ambiguity in your definition because one may think that you define g as the general ability emptied of factors abilities like verbal, numerical, spatial, working memory etc . In fact, it is the common source of variance to all those factors abilities. So it is the highest ranked common factor applying to all tests wich is usually extracted from the first rank factors : those specific abilities. What you cancel out with an infinite number of tests, is the specificity (and the error). The specificity is the variable wich explains variations on only one test . So the more test you have (complex and varied ), the more s reaches 0 and the rest goes to g and non g non s wich is those special factors.
So the fact that the g canning been explained by the first order factors (verbal spatial) and must be more abstract doesn’t mean it ´s a mn independent source of variation (contrary to s) because it is extracted from those first order factors . The easiest intuitive way to see is it is like the last common factor (the hierarchical model of extraction ) . To see a consequence : For example if someone standing on a factor like spatial ability drops, it’s g will also drop.
Nb : i ve only read first chapters of Jensen so I may be wrong. So don’t hesitate to check it . And I am writing while in a boring party 😉
Bruno i could be confused, but i think if you had an infinite number of verbal tests, all the verbal specificity would cancel out leaving you with a pure measure of verbal ability, but if you had a large number of tests each measuring a different first order (verbal, spatial, numerical, social, musical), both first order factors & test specificity would cancel out leaving you with pure g.
In other words, each subtest has three independent sources of variance (g, first order factors, & test specificity). So all tests correlate because they measure g, but all verbal tests correlate even more because they measure both g and the same first order factor (verbal)
Because test specificity is unique to each test, it cancels out everytime you add more tests, but because first order factors are unique to each type of test (i.e. verbal, spatial), they cancel out the more test types you add, so g is the only thing that doesn’t cancel out in a battery of many first order factors.
I think you’re perfectly right except if there is not an unlimited number of non-g factors (of g-1 order) emerging from you re infinite number of « type » of tests ( in that case, the number of type of tests would be finite because their wouldn’t be specific g-1 order factor to measure). So I guess this is related to the hypothesis of all faculties being réductible or not to one general ability (or g). Accumulating psychometric data and testing them on social and physiological ones is the only way to know.
I think you re fine on g 😉
I don’t get it, may be my IQ is too low, but why do you call them non-g abilities if they are correlated with g as all cognitive abilities are ?
Non-g abilities was not the best name to call them, the technical term is non-g sources of variance.
The point is even though all cognitive abilities are g loaded, there are still big differences between people with the same g on certain abilities and these are explained by verbal, spatial & other factors, along with test specificity & error.
So two people might have the exact same g but person A will have a verbal IQ of 120, a spatial IQ of 90, and a memory IQ of 90 and person B will have a verbal IQ of 95, a spatial IQ of 95 and a memory IQ of 110.
So the theory behind IQ tests is if you test many diverse abilities, the non-g variance will cancel out and the overall score will reflect g.
Of course this is never 100% true and most IQ tests will reflect non-g variance to some degree
Myopia is postively correlated to IQ as hyperopia is negatively correlated to it. One hypothesis is that some genes influence brain size and eyes size (myopia is caused by to long eyes and hyperopia by too short ones).
Afro and RR might want to correct me on this but it seems there is some biological reality to IQ other than all IQ correlates being explain by SES.
There is also a positive correlation between IQ and brain pH, how could this be explain only by SES, health and education ?
The same goes for certain diseases positively correlated to IQ.
Disease and malnutrition affect normal functioning, in vitro, and at every aspect of development so that’s not pointing to a cause. Stress can alter brain pH levels, since stress causes cortisol secretion. Stress then can change the structure and function of the hippocampus and PFC.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3491815/
Lower SES people are more likely to be stressed.
https://www.ncbi.nlm.nih.gov/m/pubmed/10681894/
Low SES people show higher basal levels of cortisol, which is related to high levels of stress.
Lower SES was associated in a graded fashion with higher basal levels of cortisol and catecholamines. These associations occurred independent of race, and the data were consistent with mediation by health practices and social factors.
https://www.ncbi.nlm.nih.gov/m/pubmed/16738073/
(Then think thst social class is way more than SES and it becomes even clearer.)
Cortisol is secreted in response to a stressor, in order to help you cope with that stressor efficiently. Exercise (hunting for our ancestors), disrupts homeostasis because of the stressors that are put on the body. The stressors then require an adaptive response, which is cortisol. Most anything our ancestors did disrupted homeostasis, causing cortisol to be secreted. Because of increased cortisol levels during times of need, you can push through certain things than if you didn’t have that cortisol increase due to the stressor that made your body secrete the extra cortisol.
Therefore stressful events can disrupt homeostasis, too leading to higher levels of cortisol which is the proxy for higher levels of previous stress. This stress then can explain brain pH levels, structural and functional differences in the brain between class/SES and other variables in the sociocognitive-affective nexus which then lead to the variation in test scores.
So social class/SES is still an explanatory factor for pH levels in the brain (despite your lack of references).
You didn’t answered for myopia/hyperopia.
What about “high IQ diseases” ?
First of all, what’s the difference between the Raven and the Matrix reasoning on WAIS? Second of all, why is Matrix reasoning not timed on WAIS? Third of all, do you think the Mensa RPM tests such as iqtest.dk and test.mensa.no deflate not only the IQ score, but the RPM score by 5-15 points?
the main difference is the raven is a group test while MR is individually administered, so you can make sure the subject is motivated & understands the instructions. It’s not timed because several WAIS non-verbal subtests require speed so they probably wanted a power test to balance things.
Ahh, so how bad is the practice effect on it?
Also, why couldn’t they make block design or visual puzzles a power test. Speaking purely about myself, I cannot make out those visual puzzles, and I think it’d be the same for other people.
Also, have you ever taken the iqtest.dk test? How close was it to your Matrox reasoning score?
Also, how come the scoring norms are different for WAIS and Ravens. For 18-19 and 16-17, WAIS matrix reasoning has the same average score and standard deviation, while the RPM has different norms for half ages. Also, would IQtest.dk fit the RPM more since it’s a more difficult test?