80%+ is what the current corpus of scientific knowledge says. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4270739/ Here's a somewhat good primer on the topic, but the wikipedia page on heritability of intelligence (and it's sources) is also somewhat good.
Presumably the only good data can come from siblings who were raised in environments dramatically different from each other and the ended up with similar IQs? It must be extremely hard to know what factors in the environment might contribute to IQ... saying the data is great sure, but I need examples of how environmental factors are removed.
I looked into it and the actual answer as with everything it’s extremely complicated and you’re original pithy 80% of IQ is heritable seems to be dependent on how much culture is involved in the testing methodology... https://blogs.scientificamerican.com/beautiful-minds/the-her...
I think the idea that we can control properly is extremely unlikely and IQ will turn out to be a lot difficult to extract from learning/society/environment than you might think, especially as findings with epigenetics and intelligence start to be shown. https://www.europeanscientist.com/en/research/epigenetics-an...
Your first link is a blogpost about someone's doctoral dissertation, and your second link is even more of a stretch (the title of the paper ends with a question mark). That is fringe research, and not the established position. You get what you search for.
As for cultural loading in intelligence tests, maybe you could expand on that? How do you measure how much culture was involved in the methodology, and how it affected the results of the tests?
There is no wikipedia page on heritability of intelligence, only heritability of IQ. It makes me consider whether the rest of what you've said is actually incorrect since you made such a conflation.
Intelligence is a notoriously hard thing to define and measure, and I think it's more easily predicted by environmental factors than genetics. The idea that smart people breed and have smart children and that's why some people are smart and others are dumb, is more of a cop-out, since predictors of success that tests like IQ try to explain are more accurately explained by socio-economic factors.
Basically this has no real world implications. I realise this isn't the argument you were trying to make necessarily, you were just pointing out a perceived 'fact', but it lacks a lot of nuance that could lead to dangerous assumptions about the real world, especially since you related it to sexuality.
If people demanded as much rigor for other subfields of psychology as they require for psychometrics of intelligence, the whole word would simply get rid of all psychology departments.
People have no clue how much more rigorous these studies than anything else in the field and adjacent fields.
Of course I demand rigor in a subfield that exists almost entirely to inform policies like segregation, eugenics, welfare, education, etc, and I find studies based on IQ tests and the g factor to be very much inadequate at being socially relevant.
My point is that you seem to not understand how rigorous is the field compared to academia as a whole and especially those fields that shape policy nowadays. In fact, intelligence research was always on the forefront of using cutting edge methodology and some tools that are used in psychology were invented specifically to research intelligence. Spearman invented factor analysis to measure cognitive performance, to this day this test is still used in behavior research.
If you think that IQ studies are inadequate, don’t even look at other fields that study humans (aside maybe from double blind trials in medicine), you are going to have a heart attack.
By your standards we need to ignore 90% of academia and solely rely on physics research to guide our policy.
I have completed over 30 ECTS credits studying econometrics in graduate school, I think I have enough grasp of statistics and factor analysis to not get schooled by some breadtuber who produces infotainment content for teenagers.
> Neither of your responses even dispute my points.
First you try to insinuate that IQ is not related to intelligence and even if it were intelligence has not practical application in the "real world".
Your first point was disputed by the comments related to how rigorously this subject is studied and documented, due to it being a third-rail area of academia.
I am going to dispute your second point myself.
That rigorous study and documentation associates IQ with intelligence and intelligence with 'g' which, although not precisely defined, is associated with (at least) higher problem-solving ability.
So now your argument reduces to "higher problem-solving ability has no practical application in the 'real world'".
And so I will just dispute that statement out of hand because problem-solving ability is what has allowed humans to become the dominant animal on Earth.
80%+ is what the current corpus of scientific knowledge says. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4270739/ Here's a somewhat good primer on the topic, but the wikipedia page on heritability of intelligence (and it's sources) is also somewhat good.