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I’ve had a few discussions with Grey Enlightenment on this blog, regarding construct validity. He has now published a response piece on his blog to the arguments put forth in my article, though unfortunately it’s kind of sophomoric.
He calls himself a ‘race realist’yet echoes the same arguments used by those who oppose such realism.
1) One doesn’t have to believe in racial differences in mental traits to be a race realist as I have argued twice before in my articles You Don’t Need Genes to Delineate Race and Differing Race Concepts and the Existence of Race: Biologically Scientific Definitions of Race. It’s perfectly possible to be a race realist—believe in the reality of race—without believing there are differences in mental traits—‘intelligence’, for instance (whatever that is).
2) That I strongly question the usefulness and utility of IQ due to its construction doesn’t mean that I’m not a race realist.
3) I’ve even put forth an analogous argument on an ‘athletic abilities test’ where I gave a hypothetical argument where a test was constructed that wasn’t a true test of athletic ability and that it was constructed on the basis of who is or is not athletic, per the constructors’ presuppositions. In this hypothetical scenario, am I really denying that athletic differences exist between races and individuals? No. I’d just be pointing out flaws in a shitty test.
Just because I question the usefulness and (nonexistent) validity of IQ doesn’t mean that I’m not a race realist, nor that I believe groups or individuals are ‘the same’ in ‘intelligence’ (whatever that may be; which seems to be a common strawman for those who don’t bow to the alter of IQ).
Blood alcohol concentration is very specific and simple; human intelligence by comparison is not . Intelligence is polygenic (as opposed to just a single compound) and is not as easy to delineate, as, say, the concentration of ethanol in the blood.
It’s irrelevant how ‘simple’ blood alcohol concentration is. The point of bringing it up is that it’s a construct valid measure which is then calibrated against an accepted and theoretical biological model. The additive gene assumption is false, that is, genes being independent of the environment giving ‘positive charges’ as Robert Plomin believes.
He says IQ tests are biased because they require some implicit understanding if social constructs, like what 1+1 equals or how to read a word problem, but how is a test that is as simple as digit recall or pattern recognition possibly a social construct.
What is it that allows individuals to be better than others on digit recall or pattern recognition (what kind of pattern recognition?)? The point of my 1+1 statement is that it is construct valid regarding one’s knowledge of that math problem whereas for the word problem, it was a quoted example showing how if the answer isn’t worded correctly it could be indirectly testing something else.
He’s invoking a postmodernist argument that IQ tests do not measure an innate, intrinsic intelligence, but rather a subjective one that is construct of the test creators and society.
I could do without the buzzword (postmodernist) though he is correct. IQ tests test what their constructors assume is ‘intelligence’ and through item analysis they get the results they want, as I’ve shown previously.
If IQ tests are biased, how is then [sic] that Asians and Jews are able to score better than Whiles [sic] on such tests; surely, they should be at a disadvantage due to implicit biases of a test that is created by Whites.
If I had a dollar for every time I’ve heard this ‘argument’… We can just go back to the test construction argument and we can construct a test that, say, blacks and women score higher than whites and men respectively. How well would that ‘predict’ anything then, if the test constructors had a different set of assumptions?
IQ tests aren’t ‘biased’, as much as lower class people aren’t as prepared to take these tests as people in higher classes (which East Asians and Jews are in). IQ tests score enculturation to the middle class, even the Flynn effect can be explained by the rise in the middle class, lending credence to the aforementioned hypothesis (Richardson, 2002).
Regarding the common objection by the left that IQ tests don’t measures [sic] anything useful or that IQ isn’t correlated with success at life, on a practical level, how else can one explain obvious differences in learning speed, income or educational attainment among otherwise homogeneous groups? Why is it in class some kids learn so much faster than others, and many of these fast-learners go to university and get good-paying jobs, while those who learn slowly tend to not go to college, or if they do, drop out and are either permanently unemployed or stuck in low-paying, low-status jobs? In a family with many siblings, is it not evident that some children are smarter than others (and because it’s a shared environment, environmental differences cannot be blamed).
1) I’m not a leftist.
2) I never stated that IQ tests don’t correlate with success in life. They correlate with success in life since achievement tests and IQ tests are different versions of the same test. This, of course, goes back to our good friend test construction. IQ is correlated with income at .4, meaning 16 percent of the variance is explained by IQ and since you shouldn’t attribute causation to correlations (lest you commit the cum hoc, ergo propter hoc fallacy), we cannot even truthfully say that 16 percent of the variation between individuals is due to IQ.
3) Pupils who do well in school tend to not be high-achieving adults whereas children who were not good pupils ended up having good success in life (see the paper Natural Learning in Higher Education by Armstrong, 2011). Furthermore, the role of test motivation could account for low-paying, low-status jobs (Duckworth et al, 2011; though I disagree with their consulting that IQ tests test ‘intelligence’ [whatever that is] they show good evidence that in low scorers, incentives can raise scores, implying that they weren’t as motivated as the high scorers). Lastly, do individuals within the same family experience the same environment the same or differently?
As teachers can attest, some students are just ‘slow’ and cannot grasp the material despite many repetitions; others learn much more quickly.
This is evidence of the uselessness of IQ tests, for if teachers can accurately predict student success then why should we waste time and money to give a kid some test that supposedly ‘predicts’ his success in life (which as I’ve argued is self-fulfilling)? Richardson (1998: 117) quotes Layzer (1973: 238) who writes:
Admirers of IQ tests usually lay great stress on their predictive power. They marvel that a one-hour test administered to a child at the age of eight can predict with considerable accuracy whether he will finish college. But as Burt and his associates have clearly demonstrated, teachers’ subjective assessments afford even more reliable predictors. This is almost a truism.
Because IQ tests test for the skills that are required for learning, such as short term memory, someone who has a low IQ would find learning difficult and be unable to make correct inferences from existing knowledge.
Right, IQ tests test for skills that are required for learning. Though a lot of IQ test questions are general knowledge questions, so how is that testing anything innate if you’ve first got to learn the material, and if you have not you’ll score lower? Richardson (2002) discusses how people in lower classes are differentially prepared for IQ tests which then affects scores, along with psycho-social factors that do so as well. It’s more complicated than ‘low IQ > X’.
All of these sub-tests are positively correlated due to an underlying factor –called g–that accounts for 40-50% of the variation between IQ scores. This suggests that IQ tests measure a certain factor that every individual is endowed with, rather than just being a haphazard collection of questions that have nothing to do with each other. Race realists’ objection is that g is meaningless, but the literature disagrees “… The practical validity of g as a predictor of educational, economic, and social outcomes is more far-ranging and universal than that of any other known psychological variable. The validity of g is greater the complexity of the task.”
I’ve covered this before. It correlates with the aforementioned variables due to test construction. It’s really that easy. If the test constructors have a different set of presuppositions before the test is constructed then completely different outcomes can be had just by constricting a different test.
Then what about ‘g’? What would one say then? Nevertheless, I’ve heavily criticized ‘g’ and its supposed physiology, and if physiologists did study this ‘variable’ and if it truly did exist, 1) it would not be rank ordered because physiologists don’t rank order traits, 2) they don’t assume normal variations, they don’t estimate heritability and attempt to untangle genes from environment, 3) they don’t assume that normal variation is related to genetic variation (except in rare cases, like down syndrome, for instance), and 4) nor do they assume within the normal range of physiological differences that a higher level is ‘better’ than a lower. My go-to example here is BMR (basal metabolic rate). It has a similar heritability range as IQ (.4 to .8; which is most likely overestimated due to the use of the flawed twin method, just like the heritability of IQ), so is one with a higher BMR somehow ‘better’ than one with a lower BMR? This is what logically follows from assuming that ‘g’ is physiological and all of the assumptions that come along with it. It doesn’t make logical, physiological sense! (Jensen, 1998: 92 further notes that “g tells us little if anything about its contents“.)
All in all, I thank Grey Enlightenment for his response to my article, though it leaves a lot to be desired and if he responds to this article then I hope that it’s much more nuanced. IQ has no construct validity, and as I’ve shown, the attempts at giving it validity are circular, and done by correlating it with other IQ tests and achievement tests. That’s not construct validity.
Here is my reply to Jared Taylor’s new article over at AmRen Breakthroughs in Intelligence:
“The human mind is not a blank slate; intelligence is biological”
The mind is not a ‘blank slate’, though there is no ‘biological’ basis for intelligence (at least in the way that hereditarians believe). They’re just correlations. (Whatever ‘intelligence’ is.)
“there is no known environmental intervention—including breast feeding”
There is a causal effect of breast feeding on IQ:
While reported associations of breastfeeding with child BP and BMI are likely to reflect residual confounding, breastfeeding may have causal effects on IQ. Comparing associations between populations with differing confounding structures can be used to improve causal inference in observational studies.
Brion, M. A., Lawlor, D. A., Matijasevich, A., Horta, B., Anselmi, L., Araújo, C. L., . . . Smith, G. D. (2011). What are the causal effects of breastfeeding on IQ, obesity and blood pressure? Evidence from comparing high-income with middle-income cohorts. International Journal of Epidemiology, 40(3), 670-680. doi:10.1093/ije/dyr020
Breastfeeding is related to improved performance in intelligence tests. A positive effect of breastfeeding on cognition was also observed in a randomised trial. This suggests that the association is causal.
Horta, B. L., Mola, C. L., & Victora, C. G. (2015). Breastfeeding and intelligence: a systematic review and meta-analysis. Acta Paediatrica, 104, 14-19. doi:10.1111/apa.13139
“before long we should be able to change genes and the brain itself in order to raise intelligence.“
Which genes? 84 percent of genes are expressed in the brain. Good luck ‘finding’ them…
These results corroborate with the results from previous studies, which have shown 84% of genes to be expressed in the adult human brain …
Negi, S. K., & Guda, C. (2017). Global gene expression profiling of healthy human brain and its application in studying neurological disorders. Scientific Reports, 7(1). doi:10.1038/s41598-017-00952-9
“Normal people can have extraordinary abilities. Prof. Haier writes about a non-savant who used memory techniques to memorize 67,890 digits of π! He also notes that chess grandmasters have an average IQ of 100; they seem to have a highly specialized ability that is different from normal intelligence. Prof. Haier asks whether we will eventually understand the brain well enough to endow anyone with special abilities of that kind.”
Evidence that intelligence is not related to expertise.
“It is only after a weight of evidence has been established that we should have any degree of confidence in a finding, and Prof. Haier issues another warning: “If the weight of evidence changes for any of the topics covered, I will change my mind, and so should you.” It is refreshing when scientists do science rather than sociology.”
Even with the “weight of evidence”, most people will not change their views on this matter.
“Once it became possible to take static and then real-time pictures of what is going on in the brain, a number of findings emerged. One is that intelligence appears to be related to both brain efficiency and structure”
Patterns of activation in response to various fluid reasoning tasks are diverse, and brain regions activated in response to ostensibly similar types of reasoning (inductive, deductive) appear to be closely associated with task content and context. The evidence is not consistent with the view that there is a unitary reasoning neural substrate. (p. 145)
Nisbett R. E., Aronson J., Blair C., Dickens W., Flynn J., Halpern D. F., Turkheimer E. Intelligence: New findings and theoretical developments. American Psychologist. 2012;67:130–159. doi: 10.1037/a0026699.
“Early findings suggested that smart people’s brains require less glucose—the main fuel for brain activity—than those of dullards.”
Cause and correlation aren’t untangled; they could be answering questions in a familiar format, for instance, and this could be why their brains show less glucose consumption.
“It now appears that grey matter is where “thinking” takes place, and white matter provides connections between different areas of grey matter. Some brains seem to be organized with shorter white-matter connections, which appear to allow more efficient communication, and there seem to be sex differences in the ways the part of the brain are connected. One of the effects of aging is deterioration of the white-matter connections, which reduces intelligence.”
Read this commentary (pg. 162): Norgate, S., & Richardson, K. (2007). On images from correlations. Behavioral and Brain Sciences, 30(02), 162. doi:10.1017/s0140525x07001379
“Brain damage never makes people smarter”
This is wrong:
You would think that cutting out one-half of people’s brains would kill them, or at least leave them vegetables needing care for the rest of their lives. But it does not. Consider this striking story. A boy starts having seizures at 10 years of age when his right cerebral hemisphere atrophies. By the time he is 12, the left side of his body is paralyzed. When he is 19, surgeons decide to operate and remove the right side of his brain, as it is causing gits in his intact left one. You might think this would lower his IQ or leave him severely retarded, but no. His IQ shoots up 14 points, to 142! The mystery is not so great when you realize that the operation has gotten rid of the source of his fits, which had previously hampered his intelligence. When doctors saw him 15 years later, they described him as “having obtained a university diploma . . . [and now holding] a responsible administrative position with a local authority.”
Skoyles, J. R., & Sagan, D. (2002). Up from dragons: the evolution of human intelligence. New York: McGraw-Hill (pg. 282)
“Prof. Haier wants a concerted effort: “What if a country ignored space exploration and announced its major scientific goal was to achieve the capability to increase every citizen’s g-factor [general intelligence] by a standard deviation?””
Don’t make me laugh. You need to prove that ‘g’ exists first. Glad to see some commentary on epigenetics that isn’t bashing it (it is a real phenomenon, though the scope of it in regards to health, disease and evolution remains to be discovered).
As most readers may know, I’m skeptical here and a huge contrarian. I do not believe that g is physiological and if it were then they better start defining it/talking about it differently because I’ve shown that if it were physiological then it would not mimick any known physiological process in the body. I eagerly await some good neuroscience studies on IQ that are robust, with large ns, their conclusions show the arrow of causality, and they’re not just making large sweeping claims that they found X “just because they want to” and are emotionally invested in their work. That’s my opinion about a lot of intelligence research; like everyone, they are invested in their own theories and will do whatever it takes to save face no matter the results. The recent Amy Cuddy fiasco is the perfect example of someone not giving up when it’s clear they’re incorrect.
I wish that Mr. Taylor would actually read some of the literature out there on TBI and IQ along with how people with chunks of their brains missing can have IQs in the normal range, showing evidence that most a lot of our brain mass is redundant. How can someone survive with a brain that weighs 1.5 pounds (680 gms) and not need care for the rest of his life? That, in my opinion, shows how incredible of an organ the human brain is and how plastic it is—especially in young age. People with IQs in the normal range need to be studied by neuroscientists because anomalies need explaining.
If large brains are needed for high IQs, then how do these people function in day-to-day life? Shouldn’t they be ‘as dumb as an erectus’, since they have erectus-sized brains living in the modern world? Well, the human body and brain are two amazing aspects of evolution, so even sudden brain damage and brain removal (up to half the brain) does not show deleterious effects in a lot of people. This is a clue, a clue that most of our brain mass after erectus is useless for our ‘intelligence’ and that our brains must have expanded for another reason—family structure, sociality, expertise, etc. I will cover this at length in the future.
by Scott Jameson
RaceRealist and I have been ruminating on a lot of stuff lately. Here’s a fun one: what economic system works best relative to what we know about human health? In my mind there are two approaches: the libertarian approach, and quasi-fascism.
In the libertarian approach, there’s no regulation of sugar placed in our food. That’s already the case. But here’s an improvement: you don’t have to pay for anyone’s gastric bypass after they overeat that sugar.
In the fascist approach, there is regulation of sugar, because a fascist state does not allow people to poison each other for profit. You still have to pay for others’ medical expenses, but those expenses will be lower.
Here’s an advantage to the libertarian approach. In that society, the people who stuff their faces and refuse to get off the couch- who are dumber and lazier on average, probably- will have a higher mortality rate on average. Eugenics need not cost a dime.
But you run into a snag, sand in the gears of your hands-off system, when Big Food kicks out a whole bunch of crappy dietary advice, at which point a minority of reasonably intelligent people will be led astray, perhaps to the grave. How could a libertarian society stop that from taking place? Would it even bother? Could the system broadly work in spite of this snag?
A libertarian society doesn’t pay for idiots to have children. That’s good, but half of your population (women) are unlikely to ever support it. Women don’t do libertarianism; observe Rand Paul’s demographic Achilles Heel on page 25. When women asked men what to do about so-and-so’s eighth unpaid for child, we’d have to look them in the eyes and give a deadpan “let’s hope private charity can handle it.” There was a time, before FDR, when women would’ve accepted that answer. They were still in the kitchen back then, and I don’t know how to put them back there.
A fascist society has more hands-on eugenics, possibly genome editing or embryo selection. Also good. Expensive, but obviously worth it.
We welcome your input on these issues.
As an aside, White men are well-known as the most conservative, small government, nationalist group out there in our current political atmosphere. I always hear people spewing the schmaltziest nonsense about the values of the Founding Fathers. They were, relative to our political compass, nationalist libertarians. Accordingly, modern nationalists and libertarians do best with the exact same demographics that used to vote on candidates back then: property-owning White men. The sole reason that Ron and Rand Paul couldn’t get elected is that they are too similar to the Founding Fathers. Any other candidate who blathers on about the Founding values is simply a liar, and their obvious lies show a disrespect of your intelligence.
If you’re a libertarian, but not an ethno-nationalistic and patriarchal thinker, then you simply haven’t gotten the memo: women and minorities do not want to create the same world that you do, nor will they ever. Evolution gave us women who want social safety nets and other races which are better off if they parasitize off of your tax dollars. All of the most libertarian societies that ever existed (early US, ancient Athens, Roman Republic) were entirely run by White men, and adding women to the electorate gave us the welfare state. Aristophanes was right.
We’re also ruminating on the difference between IQ and expertise. I know of no mentally complicated task of which one can be a master without being intelligent. Take the IQs of chess grandmasters and you will find no morons.
Contrast that with purely physical activities. I bet you there are some really stupid people out there who are great at dancing for example. A prodigiously capable cerebellum may not predict an equally capable frontal lobe.
Discounting tasks which exclusively require things like simple physical coordination, muscle memory, etc, I ought to think that IQ is the biggest component of expertise.
Is the human brain ‘special’? Not according to Herculano-Houzel; our brains are just linearly scaled-up primate brains. We have the number of neurons predicted for a primate of our body size. But what does this have to do with general intelligence? Evolutionary psychologists also contend that the human brain is not ‘special’; that it is an evolved organ just like the rest of our body. Satoshi Kanazawa (2003) proposed the ‘Savanna Hypothesis‘ which states that more intelligent people are better able to deal with ‘evolutionary novel’ situations (situations that we didn’t have to deal with in our ancestral African environment, for example) whereas he purports that general intelligence does not affect an individuals’ ability to deal with evolutionarily familiar entities and situations. I don’t really have a stance on it yet, though I do find it extremely interesting, with it making (intuitive) sense.
Kanazawa (2010) suggests that general intelligence may both be an evolved adaptation and an ‘individual-difference variable’. Evolutionary psychologists contend that evolved psychological adaptations are for the ancestral environment which was evolved in, not in any modern-day environment. Kanazawa (2010) writes:
The human brain has difficulty comprehending and dealing with entities and situations that did not exist in the ancestral environment. Burnham and Johnson (2005, pp. 130–131) referred to the same observation as the evolutionary legacy hypothesis, whereas Hagen and Hammerstein (2006, pp. 341–343) called it the mismatch hypothesis.
From an evolutionary perspective, this does make sense. A perfect example is Eurasian societies vs. African ones. you can see the evolutionary novelty in Eurasian civilizations, while African societies are much closer (though obviously not fully) to our ancestral environment. Thusly, since the situations found in Africa are not evolutionarily novel, it does not take high levels of g to survive in, while Eurasian societies (which are evolutionarily novel) take much higher levels of g to live and survive in.
Kanazawa rightly states that most evolutionary psychologists and biologists contend that there have been no changes to the human brain in the last 10,000 years, in line with his Savanna Hypothesis. However, as I’m sure all readers of my blog know, there were sweeping changes in the last 10,000 years in the human genome due to the advent of agriculture, and, obviously, new alleles have appeared in our genome, however “it is not clear whether these new alleles have led to the emergence of new evolved psychological mechanisms in the last 10,000 years.”
General intelligence poses a problem for evo psych since evolutionary psychologists contend that “the human brain consists of domain-specific evolved psychological mechanisms” which evolved specifically to solve adaptive problems such as survival and fitness. Thusly, Kanazawa proposes in contrast to other evolutionary psychologists that general intelligence evolved as a domain-specific adaptation to deal with evolutionary novel problems. So, Kanazawa says, our ancestors didn’t really need to think inorder to solve recurring problems. However, he talks about three major evolutionarily novel situations that needed reasoning and higher intelligence to solve:
1. Lightning has struck a tree near the camp and set it on fire. The fire is now spreading to the dry underbrush. What should I do? How can I stop the spread of the fire? How can I and my family escape it? (Since lightning never strikes the same place twice, this is guaranteed to be a nonrecurrent problem.)
2. We are in the middle of the severest drought in a hundred years. Nuts and berries at our normal places of gathering, which are usually plentiful, are not growing at all, and animals are scarce as well. We are running out of food because none of our normal sources of food are working. What else can we eat? What else is safe to eat? How else can we procure food?
3. A flash flood has caused the river to swell to several times its normal width, and I am trapped on one side of it while my entire band is on the other side. It is imperative that I rejoin them soon. How can I cross the rapid river? Should I walk across it? Or should I construct some sort of buoyant vehicle to use to get across it? If so, what kind of material should I use? Wood? Stones?
These are great examples of ‘novel’ situations that may have arisen, in which our ancestors needed to ‘think outside of the box’ in order to survive. Situations such as this may be why general intelligence evolved as a domain-specific adaptation for ‘evolutionarily novel’ situations. Clearly, when such situations arose, our ancestors who could reason better at the time these unfamiliar events happened would survive and pass on their genes while the ones who could not die and got selected out of the gene pool. So general intelligence may have evolved to solve these new and unfamiliar problems that plagued out ancestors. What this suggests is that intelligent people are better than less intelligent people at solving problems only if they are evolutionarily novel. On the other hand, situations that are evolutionarily familiar to us do not take higher levels of g to solve.
For example, more intelligent individuals are no better than less intelligent individuals in finding and keeping mates, but they may be better at using computer dating services. Three recent studies, employing widely varied methods, have all shown that the average intelligence of a population appears to be a strong function of the evolutionary novelty of its environment (Ash & Gallup, 2007; D. H. Bailey & Geary, 2009; Kanazawa, 2008).
Who is more successful, on average, over another in modern society? I don’t even need to say it, the more intelligent person. However, if there was an evolutionarily familiar problem there would be no difference in figuring out how to solve the problem, because evolution has already ‘outfitted’ a way to deal with them, without logical reasoning.
Kanazawa then talks about evolutionary adaptations such as bipedalism (we all walk, but some of us are better runners than others); vision (we can all see, but some have better vision than others); and language (we all speak, but some people are more proficient in their language and learn it earlier than others). These are all adaptations, but there is extensive individual variation between them. Furthermore, the first evolved psychological mechanism to be discovered was cheater detection, to know if you got cheated while in a ‘social contract’ with another individual. Another evolved adaptation is theory of mind. People with Asperger’s syndrome, for instance, differ in the capacity of their theory of mind. Kanazawa asks:
If so, can such individual differences in the evolved psychological mechanism of theory of mind be heritable, since we already know that autism and Asperger’s syndrome may be heritable (A. Bailey et al., 1995; Folstein & Rutter, 1988)?
A very interesting question. Of course, since it’s #2017, we have made great strides in these fields and we know these two conditions to be highly heritable. Can the same be said for theory of mind? That is a question that I will return to in the future.
Kanazawa’s hypothesis does make a lot of sense, and there is empirical evidence to back his assertions. His hypothesis proposes that evolutionarily familair situations do noot take any higher levels of general intelligence to solve, whereas novel situations do. Think about that. Society is the ultimate evolutionary novelty. Who succeeds the most, on average, in society? The more intelligent.
Go outside. Look around you. Can you tell me which things were in our ancestral environment? Trees? Grass? Not really, as they aren’t the same exact kinds as we know from the savanna. The only thing that is constant is: men, women, boys and girls.
This can, however, be said in another way. Our current environment is an evolutionary mismatch. We are evolved for our past environments, and as we all know, evolution is non-teleological—meaning there is no direction. So we are not selected for possible future environments, as there is no knowledge for what the future holds due to contingencies of ‘just history’. Anything can happen in the future, we don’t have any knowledge of any future occurences. These can be said to be mismatches, or novelties, and those who are more intelligent reason more logically due to the fact that they are more adept at surviving evolutionary novel situations. Kanazawa’s theory provides a wealth of information and evidence to back his assertion that general intelligence is domain-specific.
This is yet another piece of evidence that our brain is not special. Why continue believing that our brain is special, even when there is evidence mounting against it? Our brains evolved and were selected for just like any other organ in our body, just like it was for every single organism on earth. Race-realists like to say “How can egalitarians believe that we stopped evolving at the neck for 50,000 years?” Well to those race-realists who contend that our brains are ‘special’, I say to them: “How can our brain be ‘special’ when it’s an evolved organ just like any other in our body and was subject to the same (or similar) evolutionary selective pressures?”
In sum, the brain has problems dealing with things that were not in its ancestral environment. However, those who are more intelligent will have an easier time dealing with evolutionarily novel situations in comparison to people with lower intelligence. Look at places in Africa where development is still low. They clearly don’t need high levels of g to survive, as it’s pretty close to the ancestral environment. Conversely, Eurasian societies are much more complex and thus, evolutionarily novel. This may be one reason that explains societal differences between these populations. It is an interesting question to consider, which I will return to in the future.
In 2005, Linda Gottfredson published What If the Hereditarian Hypothesis Is True? in the journal Psychology, Public Policy, and Law defending Rushton and Jensen’s (2005) conclusions on the black-white IQ gap. This gap in intelligence between the races has been noticed since the IQ test’s inception 100 years ago. What if the hereditarian hypothesis is true—what if there are genetic differences in intelligence between races? How should society handle such a ‘discovery’ if one were to occur?
In Rushton and Jensen’s opus paper, they didn’t set out to prove that the hereditarian hypothesis is true, rather they set out to prove that the hereditarian hypothesis—which states that 50 percent of racial differences in intelligence come down to genetic factors with environment dictating the other 50 percent—is more tenable the culture-only hypothesis—0 percent genetics 100 percent environment. Gottfredson states that the hereditarian hypothesis becomes scientifically plausible “only after five evidentiary requisites have been met”: “IQ differences among same-race individuals represent (a) real, (b) functionally important, and (c) substantially genetic differences in general intelligence (the g factor), and mean IQ differences between the races likewise reflect (d) real and (e) functionally important differences on the same g factor.” (Gottfredson, 2005: 311) The past one hundred years of intelligence testing has proven all of this. The black-white differences in intelligence are on subtests that are more heritable, proving a genetic component.
The hereditarian hypothesis has been proven by adoption studies such as the Minnesota Transracial Adoption Study, to differences overall in IQ tests, to differences in life success etc. Environmentalists believe it’s ‘racism’ or ‘classism’ that’s the cause for racial/ethnic/class differences in achievement, when a genetic explanation makes a lot more sense.
The Denial of the Hereditarian Hypothesis
The denial of the hereditarian hypothesis has greatly harmed American society. Before the push for multiculturalism in the 60s, a genetic reason for racial/class differences was widely accepted. Minorities couldn’t perform well in school in comparison to whites because they had lower innate g. The difference in g causes differences in wealth attainment, salary, mortality, fitness, educational attainment, and other pertinent achievements. This then leads to programs with an abysmal ‘success rate’, such as Head Start. Head Start does not work, its gains fade away in a few years after the program. It’s time to stop Head Start, because it makes people believe that parental intervention can have any kind of effect on a young child, when it’s shown that these so-called gains fade away in a few years as the heritability of intelligence increases. Individuals differ on g, races differ on g, there are differences in achievement and more people in one SES bracket and other people in another SES bracket and it’s down to g. Denying the hereditarian hypothesis wastes taxpayer money as more and more money goes towards programs like Head Start that don’t do anything to close any of the gaps they promise to close.
Academic achievement in math, science, art, humanities, and second language were all shared by the same genes. They found that 60 percent of the results in GCSE scores were attributed to genetic factors. Genes and not upbringing had more of an effect on the scores one receives on the GCSE.
Moreover, other behavioral traits such as psychopathology and personality also account for genetic influence on GCSE scores beyond that predicted by intelligence. This shows that ‘nature’ wins out in the nature-nurture debate. If individual differences in test scores are largely determined by genetics, why not the black-white difference?
Individuals nor groups are ever ‘equal’ in terms of any capacity. One will be better at something than someone else, and that will largely be determined by genetic factors. Training and repetition brings out the best in one that’s genetically inclined to excel. We accept genetic differences for differences in sports, such as sprinting and distance running. They are genetically inclined to excel at those competitions due to fast and slow twitch muscle fibers. Take Usain Bolt. Do you think anyone can train to get to that level? Do you think random Joe can just wake up one day and decide to try to be the fastest man in the world? If you say no, you’re a hereditarian. Of course Bolt’s training makes him better, but without his genetics, he wouldn’t be the fastest man in the world.
Now take the genetic differences from sports (that any sane person would recognize), and think about that in regards to brain power. We are talking about 2 groups that have been genetically isolated for tens of thousands of years. They had to do different things to survive and both faced different selective pressures that would have an effect on intelligence.
The worldwide differences in IQ between East Asians, Europeans and Africans; an inverse correlation between the race differences and brain attributes and black-white-East Asian differences in body maturation; . 2 and .4 correlations with skull size and in vivo brain volume, moderately high correlation of .6 to .7 of different IQ test’s g loadings on the magnitude of the black-white-East Asian differences as well as the measures of the subtests being rooted in biological and genetic processes; rising heritability of IQ; differences in crime, gestation, and sex ratio at birth, law-abidingness, marital stability; and a genetic divergence of world population groups during evolution. The most telling one is the last one, genetic divergence of world population groups during evolution. These differences in the brain are rooted in genetic factors. The hereditarian hypothesis fully explains within and between group differences in achievement and intelligence. No “culture-only” hypothesis could ever convince me otherwise.
Richard Nisbett has attempted to say that the hereditarian hypothesis is wrong and that culture-only theory is the only game in town. He couldn’t be more wrong. Citing studies like Moore and Eyferth to make your case against the hereditarian hypothesis won’t get you anywhere. They had a smaller sample size, and some of the subjects were extremely young. Environmentalists use these studies to say that the difference in IQ comes down to a type of ‘ghetto’ environment that saps American blacks’ intellect and that raised away from that type of environment, they’d be able to score on par with whites. Except that’s not what was found in the Minnesota Transracial Adoption Study. This is the only study to test the children again at age 17, when genetics would be taking its full effect. The racial gap in intelligence still stayed the same (Rushton and Jensen, 2005: 258). I’ve written about the strong evidence for the hereditarian hypothesis in regards to adoption studies and how they support the hypothesis that genetics, and not culture, are the cause for differences in intelligence.
If the Hereditarian Hypothesis is Accepted What Policies Should Change?
If the general public were to ever accept a genetic hypothesis for individual and group differences as a whole, then affirmative action and other such programs that shoehorn kids with lower ability into schools should be abolished and these spots should be filled on merit. Sure there would be fewer blacks and more whites, Jews, Asians, than blacks, ‘Hispanics’ and others but that’s how a merit-based society looks, not one based on feelings and imaginary causes of racism as the culprit for any types of intellectual downfalls. When we come to our senses with genetics and educational achievement and intelligence—which should be coming soon due to the advent of CRISPR—then America can start to become less polarized, in my opinion, on the so-called ‘racist system’ ‘holding down’ minorities. Maybe if people/groups accepted they were less intelligent and it was due majorly to genetic factors, then some of this racial animosity between groups in America will die down. That’s an extremely far reach, though, and I can see them then arguing that accepting by accepting the hereditarian hypothesis then we should continue these programs.
That’s an extremely far reach, though, and I can see them then arguing that accepting by accepting the hereditarian hypothesis then we should continue these programs due to genetic differences. They would say “Well, as a group, we are less inclined to make it into higher areas of learning so we, therefore, should continue to receive these benefits.” To that I would say you’ve been taking advantage of these benefits for 50 years and what’s changed? Billions of dollars have been spent on affirmative action and related cases since the 60s and what has changed? These groups still complain and talk about being oppressed by ‘the man’ not getting what they want. Yet there is an ongoing racial preference for blacks and ‘Hispanics’ over whites and Asians in US medical schools. This is all an effect of affirmative action and the policies it brings to American institutions. Admission into places of higher learning should be completely merit-based, not based on what racial/ethnic group you belong to. That in and of itself is continuing the so-called ‘racism’ and ‘prejudiced attitudes’ that people complain about since they insist on having special privileges based on their ancestral background.
If we were to accept the hereditarian hypothesis as a country, I’d hope to see an abolishment of affirmative action, Head Start, and related programs that do not work. The acceptance of the hereditarian hypothesis would only be a net gain over time, as people would learn to not blame ‘the man’ on their problems, but would look to better themselves in ways that accentuate their strengths. Since any attempt at raising scholastic achievement has failed due to the heritability of intelligence and how it increases as one ages (which is why Head Start doesn’t work and should be abolished) once this is accepted then other avenues can be taken to address these issues that don’t focus on attempting to raise scores. Gottfredson states at the end of her paper that we should have targeted intellectual support for those with an IQ below 80. She also says we should make some jobs less complex, ie “inadequate or overly complex labeling, instructions, and forms”, target training and education towards people with that level of intelligence, and provide more assistance in daily living matters, This can increase their QoL and ability to attain meaningful employment.
She sees a more positive outlook in the future than I do. I see things become more stratified as automation rolls out. This will have the lower IQ people out of work, while the higher IQ people still are sitting well at the top due to the increasingly complex society that we make for ourselves. Accepting the hereditarian hypothesis can ease this slightly by targeting programs at the less intellectually inclined as well as attempt to soften the claims of ‘racism’ when this starts to really become noticeable. The only way to explain such a disparity is with a genetic hypothesis, at least 50/50 genetics culture. The culture-only theory has no leg to stand on. Once we accept that individual and group differences are due to genetics, then we can begin to accept some of the differences in our society in terms of class and race.
Over a ten year period in France, from 1999 to 2008-9, IQ has declined in France by almost 4 points. What is the cause? Immigration? Dysgenics? A reversal of the Flynn Effect? No doubt that numerous people would attribute the decline in intelligence in France due to MENA and SSA immigration. But is this true?
Lynn and Dutton (2015) show how differing studies show both positive and negative gains in IQ. To prevent further evidence of these negative Flynn gains, they looked to the IQ of France from 1999-2009.
The WAIS-III was standardized in France in 1999 while the WAIS-IV was standardized in 2009. This was a great opportunity to see if the intelligence of the French dropped using the new WAIS-IV. The sample was of 79 people who were of a different sample than that of the broader WAIS-IV French standardization. The average age of the sample was 45, ranging between 30 and 63 years of age. Half of this sample took the WAIS-IV first while the other half took the WAIS-III first to control for practice effects. They used a separate sample to compare the norms of generated by the two standardizes samples.
The above table from the paper, table 3, shows the comparison between the two WAIS tests. Positive ds indicate lower scaled scores on the III in comparison to the IV and thusly higher scores. What these data show is that the IV is harder than the III and IQ declined because the test got ‘tougher’ (because full-scale intelligence declined). As noted above, this phenomenon of decreasing IQ scores has been noticed for about 20 years now. The symbol search showed the smallest decline while there was no change in digit span. The biggest gain was in vocabulary.
This is pretty shocking. In ten years, verbal comp decreased by 4 points, perceptual reasoning index by 3.1 points, no change in working memory index, processing speed index decreased by .7 points, perceptual organization index decreased by 3.9 and the whole full-scale IQ decreased by 3.8 points. Lynn and Dutton discuss the results:
In addition, the Full Scale IQ on the WAIS IV sample of 79 subjects was calculated based on a comparison with the WAIS IV sample of 876 subjects, which was representative of the French population on key variables such as education and region. The scores of this sample of 876 subjects were set at 100 and a comparison made with the sample of 79 subjects. As can be seen in Table 4, on this basis the IQ of the sample of 79 subjects was 101.1 with an SD of 14.7, where the French norm would be 100 and the SD 15. As such, the smaller sample can be regarded as representative of the French population in terms of intelligence.
So this small sample can be regarded as representative of the French population. Lynn and Dutton say that the digit span showing no increase corroborates findings from another researcher that showed that there was no change in forward or backward digit span in 85 years. They then say:
. . .improvements in the quality of nutrition during the twentieth century made a major contribution to increasing IQs. But it seems improbable that the quality of nutrition declined in recent years in France and in the other economically developed countries in which declining IQs have been reported.
So one possible cause is that nutrition has declined in France. From Dubuisson et al, 2010:
These repeated surveys highlighted the fact that trends in French food habits have moved towards an average European diet at the crossroads between Mediterranean and Northern diets, and that food consumption changes impacted, to a lesser extent, nutritional intake.
It shows that the French diet is in between Med and Nord diets. Really, as Lynn and Dutton asserted, there was no decline in nutritional quality for the French.
Another possible cause is a decrease in quality of schools. Flynn says a part of the reason for the rise in IQ was due to the advent of scientific thinking. However, this is not a good explanation either since school quality seems to not have been affected.
Flynn also talks about the media and its role. Lynn and Dutton say:
However, this would not explain declines in other forms of intelligence and, moreover, it might be argued that the desire and ability to read such literature would be underpinned by general intelligence and so a decline in the consumption of such literature would partly reflect a decline in general intelligence, as vocabulary is a measure of intelligence.
It is also worth noting that, apparently, reading may actually increase general intelligence (post coming on that soon).
Now, finally, the theory we’ve all been waiting for: Is it increased immigration?
Lynn and Dutton state:
This increase has occurred throughout western Europe and a number of studies have shown that immigrants from North Africa and south-west Asia typically have an average IQ of around 85 to 90 (Lynn, 2006, Lynn, 2008, Lynn and Vanhanen, 2012 and Rindermann and Thompson, 2014; for a large meta-analysis see te Nijenhuis, de Jong, Evers, & van der Flier, 2004). This conclusion has been confirmed by Kirkegaard (2013) who has shown that in Denmark the number of non-European immigrants increased from approximately 50,000 in 1980 to 400,000 in 2012 and the IQ of non-European immigrants in 18–19 year old military conscripts was 86.3, relative to 100 for indigenous Danes. These immigrants are likely to have had some impact on reducing the average IQ of the populations, but it is doubtful whether the increase in the number of immigrants with lower IQs has been sufficiently great to have had a major effect.
I personally don’t think that migration into Europe from MENA and SSA countries has been enough to put that big of a dent (over 1/3rd of an SD) in average IQ in France, and Europe as a whole. Since people are coming from areas closer to the equator and have higher rates of children since they are r-selected, could this be why France has seen a decrease in intelligence?
Woodley of Menie and Dunkel (2015) reviewed Lynn and Dutton’s paper and said:
Replacement migration in France involving populations exhibiting lower means of IQ and higher rates of total fertility, such as Algerians, Moroccans, Tunisians and Roma (Čvorić, 2014 and Lynn and Vanhanen, 2012) may be increasing the rate of secular losses at the level of g, consistent with speculations advanced in Dutton and Lynn (2015), however the additional loss in g due to this process is anticipated to be very small. Based on a simulation, Nyborg (2012) estimates that in Denmark, replacement migration may be reducing heritable g by .28 points per decade, which would increase the overall loss in g to 1.51 points per decade ( Woodley of Menie, 2015), this still being only 37.75% of the loss observed in the French cohort.
An Environmental Explanation?
Since we still need an explanation for 62.25 percent of the 3.8 decrease in full-scale IQ other than dysgenic fertility, are there any environmental explanations? Environmental explanations can be anything from child abuse, to poor schooling, to poor nutrition, etc. Was there an increase in any of these or other variables that negatively affect IQ which would explain the 3.8 point decline in IQ?
One of the most likely candidates is nutrition. Lack of certain vitamins, especially in childhood, would prevent the brain from receiving the proper nourishment to grow.
The INCA study took record of food consumption from 2,373 people aged 4 to 92 from a 7-week period and from that they saw which nutrients they were deficient in (Touvier et al 2006). To measure if and how much they were nutrient deficient, they used the Estimated Average Requirement (EAR). The vitamins used were calcium, magnesium, iron, vitamins C, A, B6, and B12, thiamin, riboflavin, niacin, pantothenic acid, and folate. A lot of these have to do with proper brain functioning and ability to reach its full-size potential. For instance like the B vitamins and iron. Being deficient in those nutrients depresses brain size and with it IQ. For instance, being deficient in vitamin B 12 and folate leads to decreased brain size in childhood. The negative effects of being deficient in these nutrients may partially explain some of the 3.8 point decrease in full-scale IQ.
Regarding the prevalence of the aforementioned nutrient deficiencies in these populations, the authors state:
We also calculated daily consumption of 44 food groups by age and gender. This paper shows how the combination of both data sets, i.e., inadequacy and food consumption data, allows a preliminary screening of potential food vehicles in order to optimize fortification. The prevalence of inadequacy was particularly high for the following groups: for calcium, females aged 10-19 years (73.5%) or aged 55-90 years (67.8%), and males aged 15-19 years (62.4%) or aged 65-92 years (65.4%); for magnesium, males aged 15-92 years (71.7%) and females aged 10-90 years (82.5%); for iron, females aged 15-54 years (71.1%); and for vitamin C, females aged 15-54 years (66.2%). Two examples are provided to illustrate the proposed method for the optimization of fortification.
Most vitamins and minerals have positive effects on brain functioning, some more than others, but notice the prevalence of iron defieciency in the females aged 15-54 years (71.1 percent). With the cohort cited by Lynn and Dutton (2015) and Woodley of Menie and Dunkel (2015) being aged 30 to 63 with an average age of 45, the prevalence of iron deficiencies in the INCA study, along with the other deficiencies in the cohort, may partially be responsible for the decline in IQ.
The Flynn Effect
One of the biggest mysteries in psychology is the Flynn Effect; the fact that over the 20th century, people have been performing better and better on IQ tests. Of course, the average IQ in Western countries by definition is always about 100, however because people keep scoring higher every decade, the tests routinely have to be made more difficult and the norms must be regularly updated to keep the mean IQ from rising far above 100.
However, in first-world countries, in the past 20 or so years, it has been in decline, particularly in France. It’s due to a mix of dysgenic fertility and nutrient deficiencies. Since Flynn gains are largely due to advancements in better nutrition, Flynn loses would then be attributed in part to nutrient deficiencies as well as dysgenic fertility.
The cause for the 3.8 decrease in IQ in France is low fertility rates amongst the French population as well as nutrient deficiencies. Clearly, ameliorating this decrease in IQ can be reversed by the K-selected having more children and healthier eating habits. Drops in IQ won’t be attributed to MENA and SSA populations until the future, but for now, the cause for the decrease is the French themselves.
[Edit: My view here has changed, read my recent article Is Diet an IQ Test? It isn’t and it is, of course, much more nuanced than ‘IQ’ (which is a proxy for social class’ leading to obesity which would imply lack of funds and education on what and when to eat. Obesity is much more complex than ‘IQ’, numerous other variables come into play and since ‘IQ’ (which is just a proxy for general knowledge ‘is low then the individual in question won’t know what and when to eat and since this occurs in low income families more often than not who have low IQs then this effects them the most.]
The relationship between intelligence and obesity is often misinterpreted. Numerous studies have concluded that becoming obese leads to a drop in IQ. This mistake happens due to improper interpretation of cross-sectional studies. However, analyses of population-based, longitudinal data show that low intelligence from birth causes obesity. No credible evidence exists for obesity lowering intelligence. There are, however, mountains of evidence showing that low intelligence from childhood leads to obesity (Kanazawa, 2014).
Kanazawa (2014), reviewed the data on the research between obesity and IQ. What he found was that those studies that concluded that obesity causes lowered intelligence only observed cross-sectional studies. Longitudinal studies that looked into the link between obesity and intelligence found that those who had low IQs since childhood then became obese later in life and that obesity does not lead to low IQ. Those with IQs below 74 gained 5.19 BMI points, whereas those with IQs over above 126 gained 3.73 BMI points in 22 years, which is a statistically significant difference. Also noted, was that those at age 7 who had IQs above 125 had a 13.5 percent chance of being obese at age 51, whereas those with IQs below 74 at age 7 had a 31.9 percent chance of being obese. This data makes it clear: low IQ is correlated with obesity, so we, therefore, need to find sufficient measures to help those with lower IQs to learn how to manage their weight. Moreover, the lack of ability to delay gratification is also correlated with low IQ (Mischel, Ebbeson, and Zeiss, 1972).
Less intelligent individuals are more likely to become obese than those who are more intelligent. With what we know about low IQ people and how there is a strong relationship between low intelligence and lack of ability to delay gratification, we can see how this lack of thought for future problems for their actions in the present can manifest itself in obesity.
This study claims that there is a link between morbid obesity and a drop in IQ. The researchers compared 24 children who weighed 150 percent of their bodyweight before age 4 with 19 children and adults with Prader Willi’s Syndrome, using 24 siblings as controls as “they share the same socioeconomic environment and genetics”. Prader Willi’s Syndrome (PWS) is a chromosomal disorder in which chromosome 15 is deleted. They have an almost insatiable desire to eat,which can cause one suffering from PWS to eat themselves to death. Those with PWS were found to have an IQ of 63, while those who became obese were found to have an IQ of 78 with the control siblings having an IQ of 106. The researchers were surprised to see such a difference in IQ between siblings. They then state that this could be one facet of obesity that could be irreversible. MRI scans of the cohort discovered white matter lesions on the subjects with PWS and early-onset obesity. The researcher says that these lesions could affect food seeking centers in the brain leading to a want to gorge on food. Seeing how those with PWS eat when unsupervised, this is an interesting hypothesis.
This study compared 49 teens with metabolic syndrome and 62 peers without the disorder, while controlling for socioeconomics status. They found significantly lower scores in arithmetic, attention and attention span, spelling, mental flexibility and regions of the brain with lower volumes of matter in the hippocampus and white matter integrity.
There are a few problems with these two studies. In a population-representative birth cohort study of 1037 children, it was found that cohort members who became obese had a low IQ, as expected. But, contrary to what your study said, cohort members didn’t exhibit a decline in IQ from becoming obese, they instead had a lower IQ since childhood. There is no evidence of obesity contributing to a decline in IQ, even in obese individuals and those on the verge of metabolic syndrome. Another problem is that they wrongly conclude that obesity leads to lowered intelligence, completely misinterpreting the extremely strong negative correlation between obesity and intelligence.
This study shows how obese mothers give birth to less intelligent children. In an observational study (already garbage), the researchers took 3412 participants and found a strong relationship with pre-pregnancy obesity and math and reading scores in children. For math, a 3 percent reduction was observed. There was a 3-point drop in reading scores with math scores showing a decline of 2 points. These differences are within the normal variation between tests, so it’s nothing to take note of. Also, this is an observational study. I have shown above that longitudinal studies are superior for this, as well as researchers misinterpreting the results found from their studies.
There is a strong relationship between parental years of education and childhood obesity. Since the mother’s IQ is the most important predictor of a child’s IQ *, that passes on to the child as well. (BMI is also 80 percent heritable). **.
So because of those factors involving the mother and child, that is what accounts for it. Not the environmental factors brought up.
This study claims that overweight parents are more likely to fail. This is all due to the fact that low IQ people are more likely to be obese or overweight, with heritability of BMI being .8, you can see how low IQ is the cause of both of those variables.
This shows that binge eating is linked to memory loss. I heard about a study a few months ago actually like this. Rats were fed high fat diets and they noticed that the brain microglia actually started to eat neuronal pathways actually leading to a decrease in cognitive ability. But they said that returning to a new diet will stop its effects. Researchers say the negative cognitive effects are reversible, but I already gave the citstion about obesity not being linked to decreased IQ. I should also note that this study was carried out on rats and while this may be a factor for humans as well, a few studies need to be done.
Binge eating, however, actually has a genetic component. Though this was only observed in girls. One reason I can think of for this is that women need higher body fat for a leptin release so puberty can begin so they can bear children.
This article purports to show 5 ways obesity affects the brain. Obesity does cause food addiction, however, those who lack the ability to delay gratification are more likely to not be able to control their impulse to overeat. I always link to the MRI scan showing the control, obese and cocaine user’s brain. Interesting to see that sugar is just as addictive as cocaine. Obesity doesn’t make us more impulsive. Check out the Marshmallow Experiment, as well as its follow-up studies. Those who are more impulsive are more likely to be obese, as well as have lower SAT scores.
Satoshi Kanazawa also noted that childhood IQ predicted whether or not one would become obese at the age of 51. General intelligence in childhood has a direct effect on weight gain, BMI, and obesity, net of parents education and SES, parents BMI, the child’s social class, and sex. More intelligent children grew up to make healthier choices, and therefore stayed leaner than those children who were less bright. The link between childhood obesity and intelligence also shows that the effect between childhood g is unmediated by education of income. Meaning, those with lower IQs in a higher socioeconomic bracket STILL have the same chance of becoming obese as those in the lower socioeconomic bracket. Finally, parental BMI itself is a consequence of parental general intelligence, which the parents pass on to their children. This shows the extremely high heritability of obesity as well as showing how intelligence plays a factor in the causes of obesity.
The known differences in ethnic obesity rates generally mirror the intelligence of those populations. All populations are showing a sharp dysgenic decline, which coincides with a more obese population as well. Sociologists and the like may say that those who are poor cannot afford the same types of food that those who have more wealth can. However, this is a false statement. Whole foods are not more expensive. The conclusion that was (obviously) reached is that there is expensive and non-expensive junk food as well as whole foods. Natural diets will not cost more, all things being equal. If you know how to eat and how to buy food, you will avoid spending too much money. This goes back to intelligence. One with a higher IQ will be able to think of what his present actions will lead to in the future while those with a lower IQ live in the now without a care for the future, which then manifests itself in their obesity.
There are numerous articles showing that the causality for low intelligence is not becoming obese, but that those who become obese have a lower IQ since childhood. Longitudinal studies show the relationship, while observational studies show that obesity drops intelligence. Clearly, observational studies are inferior for seeing the relationship between IQ and obesity. This then leads to researchers misinterpreting the data and drawing wrong conclusions.
** This is a great one. In a meta-analysis of twin and family studies, including mono and dizygotic twin studies, with a sample of 140,525 people, heritability of BMI was found to be between .75 and .82. Both extremely high correlations. Since the heritability of intelligence as well as height (another good predictor of intelligence), there is good evidence for the claim that becoming obese is due to lower childhood IQ, which is genetic in nature.
The Chinese have one of the highest IQs in the world. Their 100 and 108 in Hong Kong give them an average of 104. Chinese intelligence has been increasing from the 1940s all the way to today. This is the ‘Flynn Effect’ in action. Lui and Lynn (2013) reported that IQ scores are improving for 12-year-old Chinese children. The increases are as follows: 6.19 points for full-scale IQ, 6.55 points for performance IQ, and 1.91 points for verbal IQ. The Jintan Child Study is an ongoing longitudinal study to show the effects of health and cognitive ability.
They used 1656 6th graders (55.5 percent boys and 45.5 percent girls, “consisting of 24.3% of all children in this age range in the Jintan city region born in 1999.”) who either graduated or currently were in the grade with an average age of 12.2 years. The study from 86-87 used only individuals from urban areas, so Liu and Lynn did the same. They conclude that over the 26 years from the original study, between the two data sets that increases of 2.38 points on full-scale IQ, .73 points on verbal, and 2.52 points on performance IQ per decade. They theorize that economic development is a cause of rising IQ scores due to better nutrition. The study concludes a 105.89 IQ for the 12-year-olds in the study.
Liu and Lynn (2015) also observed the same sex differences in the same magnitude in Chinese and American boys and girls. In a study of 788 children aged 12 years old, boys obtained a higher IQ by 3.75 points on average. This exactly mirrors what Rushton and Jackson (2005) say about American men and women who are college aged. They state that males score 3.63 points higher than women. Liu and Lynn state that boys obtained 4.20 points higher in performance IQ, and 2.40 points higher in verbal IQ. This is what we would expect, evolutionarily speaking. The men need to be more intelligent to provide food, whereas women need to have a higher verbal IQ to be able to talk to and take care of children. The fact that the magnitude of sex differences in IQ between men and women has been noticed in the U.S. and China shows that sex differences in the brain do exist.
Better nutrition is a definite cause for the rise in IQ for the Chinese. Richard Lynn says that better nutrition is critical for increased cognitive functioning. This is one reason why Africa’s IQ is so low. Due to more Chinese getting better jobs and making more money, they were getting higher quality foods in order to be adequately nourished. Better nutrition explains most, if not all of the Flynn Effect. It’s what to expect if this phenomenon was not on g (it’s not), it’s on the intelligence that is affected by the environment, hence, bigger increases on that type of intelligence in comparison to the intelligence highly correlated with g.
The Chinese have the largest cranial capacity at 1492 ml. The bigger one’s brain, the more cortical neurons it has which allows for better cognitive processing. Piantadosi and Kidd (2016) corroborated one of Rushton’s theories on brain size and child rearing. Mainly that r/K selection theory explains Piantadosi and Kidd’s theory of earlier births being correlated with higher intelligence due to greater necessity to care for the more vulnerable child in comparison to those with smaller brains. Moreover, since East Asians have more myelin in the brain, this too adds to their higher cognition. Since the correlation between brain size and IQ is .35, a good amount of the variance in IQ can be explained by brain size.
We can also look at Chinese outside of China. Singapore, for instance, has an IQ of 108, the highest in the world. They’re also 74.4 percent Chinese. This is then mirrored in their IQ as well as their economy. Anywhere the Chinese go they are high achievers in both IQ as well as wealth attainment.
There are other measures to show that Chinese have higher IQs. In tests of reaction times, Rushton and Jensen (2005) say that East Asians beat whites while whites beat blacks. Since faster reaction times are associated with a more efficient brain, East Asians have a higher IQ as a result of that. Though, they are weak on verbal IQ, average 99 for Chinese in America and China, they are superior in visio-spatial IQ. This is due to their ancestors evolving in the harsh winters of Siberia which lead to being more K-selected and selecting for bigger brains which lead to children being born earlier and higher intelligence evolving to better care for defenseless children. Bigger brains also evolved due to colder temperatures, which is another cause for earlier childbirth and an even bigger increase in general intelligence to adapt.
IQ in China is higher in urban areas than in rural areas, which is seen in America as well. This is due to those with higher intelligence having the ability to be able to live in the city due to a better ability to attain wealth due to higher IQ. Those in rural areas have lower IQ, some having a lower IQ genetically, while others are depressed by bad nutrition. So with better nutrition, a lot of the rural Chinese would get an IQ boost. Nutrition is critical for brain development in vitro as well as in early childhood leading into young adulthood. This ensures the brain has adequate nutrients for growth and in turn grows to its full potential.
The Chinese are the best example of Rushton’s theory of intelligence and brain size. No matter where they go, if they have adequate nutrition, they have the biggest brains and highest IQs which shows in scholastic achievement as well as wealth attainment. The increase in full-scale IQ for China in the past 30 years is due to better nutrition as well as economic growth. Singapore has one of the world’s best economies and is 74.4 percent Chinese.
This extreme K-selection, though, is causing the Chinese birth rate to drop. This is the curse for high IQ peoples. They have a lower birth rate in comparison to those with lower IQs who have a higher birth rate. The current birth rate in China is 1.66. That is devastatingly low, almost as low as Germany and Japan (both at 1.3) and they have similar IQs as well. It seems that this intelligence increase is coming with a lower birth rate. Higher intelligence is correlated with a lower sex drive so this is another cause for the lower birth rate in East Asian countries as these slight IQ increases continue to occur. The same sex differences as seen in America were also seen in China, giving more evidence to the sexual selection theory of intelligence.