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I have asked Helmuth Nyborg how it is possible that average western IQ is going down and keeps growing at the same time, as he claimed in https://lesacreduprintemps19.files.wordpress.com/2011/04/nyborg-2011-the-decay-of-western-civilization-double-relaxed-darwinian-selection.pdf? He responded that Flynn effect (test smartness) measures the "phenotypic IQ" whereas

The dysgenic effect of low-IQ immigration and internal condition, in which low-IQ parents have fewer children than high-IQ parents is a g-effect, driving genotypic IQ Down.

He says that

Arthur Jensen describes these tendencies in his famous book: The g factor, published in 1998 on Praeger Press."

Indeed, this makes sense but I do not understand how can these psychologists measure the genotypic IQ? I believe that IQ is a phenotypic manifestation of the genotype. DNA has no brain to measure the intelligence. Yet, genotype can develop into a phenotype. The only way I see that you can measure the genetic IQ is after the genotype has developed into a phenotype. Therefore, phenotypical and genotypical IQ is the same thing. I therefore do not understand how there can be difference between genotypical and phenotypical IQ. What are they talking about? How do they measure it? Is it just fascist nonsense?

12 Dec 2013 From recent email from Nyborg

If you adjust for heritability by multiplying measured IQ by, say, .6, .7, or .8 (depending on how heritabable you find IQ is), you get a rough estimate of “genotypic” IQ (a term that may be slightly misleading, as you have not factually accounted for the genetic basis of IQ). The Flynn rise in IQ possibly has to do with factors like testsmartness, nutrition, environmental stimulation etc.

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While its still a subject of debate, its not really clear that IQ is solely a genetic phenomenon. The genetic factors which are related to IQ are not simple either - racial IQs or IQ by pedigree doesn't entirely explain what we see. –  shigeta Nov 21 '13 at 11:52
Do they mean that genotypic = biological yet phenotypic = cultural? I treat the phenotypic as bilology. Despite the IQ, raised through better education, allows the genes to express better, you still cannot say that cultural aspect is the phenotype at my, uneducated, look. –  Val Nov 21 '13 at 12:01
Phenotype is said to be the physical manifestation of genotype in the organism. For example someone has the genotype of a Y chromosome and physically is a male. While some argue that culture is a phenotype, strictly speaking it is not entirely a phenotype since it depends on the local geography and other environmental factors - make sense? –  shigeta Nov 21 '13 at 12:27
I do not know if it makes sense because I ask what do these IQ researchers mean by phenotype. Secondly, I see that the culture cannot be a phenotype simply because it is not manifistation of your genome. The fact that you, as child, was exposed to the threasures of human mind, created by other DNAs, does not make them manifistations of your genome. Your DNA cannot be credited for creating the culture around you and, therefore, the culture is not your individual phenotype, ok? This has nothing to do with the geography or environment. –  Val Nov 21 '13 at 12:49
They may also be saying phenotypic IQ is the actual IQ (so cultural + biological), and genotypic IQ is what you would expect given the person's genes, pedigree, etc. But no matter what they actually mean, your last sentence was spot on. This is non-sense –  von Mises Nov 21 '13 at 16:02

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