American IQ scores have rapidly dropped, proving the 'Reverse Flynn effect'

In the absence of reasonably strong natural selection pressure to select for IQ, how could IQ not be falling over time?

IQ at best measures something that correlates with SAT. And with better education, less exposure to damaging pollutants, etc. it should always be on the rise (as demonstrated by the Flynn effect; an effect which this poor paper desperately tries to refute).

IQ research has always been about proving the superiority of one race over others, this superiority doesn’t exist, but that doesn’t stop these pseudo-scientist from trying. They bend the definition of “intelligence” and device test batteries (and in this case, interpret test battery) in skewed and bias ways to manipulate results like these. Regrettably media outlets like the Popular Mechanics and lifestyle journalists like Tim Newcomb take these researchers at their words and publish their results, despite their results pretty much being lies.

It is incredibly arguable if during an obesity crisis if population wide health is actually improving and if population wide health isn’t improving that could certainly contribute to lower IQ. We’re also seeing population wide declines of health in other ways like sperm count. Food is becoming less nutritious as soil depletes. Our fish stocks being about to collapse is going to be another hit against brain health as omega 3s will become rarer in the diet.

The heritability of IQ is only well established within true believers of a pseudo-science tightly linked with the eugenics movement. Most psychologists today believe that the supposed heritability was observed because of bias within the research. And given the people who were doing these research in the 1970s and the 1980s, and their motivation for doing those, there is no question on what these biases were. Some of the researchers went so went quite far in bending the data such that it would fit their narrow—and racist—world view. They tried really hard to define intelligence such that it would make rich white people smarter, they were regrettably successful for far to long, but ultimately failed.

Your anecdotal evidence of high IQ parents (ugh!) having high IQ children is the same anecdotal evidence that sociologists have been describing for decades that high SES parents have high SES children, and is the main reason for why parents with high SAT scores are likely to have children with high SAT scores.

What IQ researchers discovered was basically the same thing that Marx described in 1867, class, however the eugenics were no communists, and instead of providing the simpler explanation, that society rewards the ruling elite, and wealth inherits, the eugenics went all conspiratorial and blamed other races for their perceived decline in society.

* IQ is real, measurable and heritable. The evidence for this is overwhelming.

* Nobody argues about the broad heritability of other human traits such as hair/eye color, height, athletic ability and the like.

* The argument over IQ is a consequence of terrible historical experiences with eugenics and racial discrimination. Many have adopted the quasi-religious viewpoint that IQ is not heritable to sidestep the discussion.

* As a consequence, social policy resembles the cycles and epicycles of Ptolemy's cosmology. Namely, all manner of social, economic and historical outcomes which are explained parsimoniously by understanding IQ as heritable are instead attributed to a Rube-Goldberg machine of racism, class warfare and the like.

* Accepting IQ as heritable does not, in an enlightened society, require acceptance of racism or classism, any more than people are forced to discriminate against those who, say, are genetically weaker athletes due to low relative VO2 levels.

* Social policy could be enhanced and better targeted by targeting those at the lower end of the IQ curve with subsidies such as basic income.

* Accepting IQ as real, heritable and measurable represents one of the only paths out of the present morass of corrupt political patronage programs around specific groups, just as rejection of Ptolemy's worldview enabled turning away from the demon-haunted world of religion.

If you're going to build a whole chain of logic, one that attempts to solve racism somewhere in the middle and ends with the "demon-haunted world of religion", it's useful to clearly define your terms first.

in both of those cases, as in all things genetic, expanding the ceiling is a far different matter. There is no known treatment I could have been given to enable me to run a 2 hour marathon. Similarly, there is no known way to cause a 100-IQ person to reliably test at a 140 IQ.

That said, progress is being made on artificial intelligence and genetics, so that could all change.

(I find it helpful to remember that lipstick-wearing is highly heritable despite zero genetic determination, and number of toes isn't very heritable at all despite total genetic determination.)

In particular, you can't convincingly go from discussing the seemingly profound effects acknowledging IQ heritability will have on racism, in order to avoid "demon-haunted" religious arguments, to a shrug and a handwave about genotypic (and epigenetic) effects vs. environmental effects. With due respect to your good-faith attempt to establish a logical baseline to this whole situation, the demons are haunting your argument, not those of people who'd push back on it.

It's an earlier rebuttal and you can find more precise and current ones now, but Ned Block's heritability piece is a good starting point for this stuff (you can just Google for "ned block heritable", the SERP will be dozens of links to it.)

> I don't understand how your logic holds together once you concede that heritability doesn't mean "genetically determined".

And you wrote:

> You literally just said that you were using "heritability" as a synonym for "genetic determination". No, you can't do that.

I'm not sure which sentence I'm supposed to take as you saying what you mean, but yes, I can say I'm using "heritability" as a synonym for "genetic determination."

And, of course there is plenty of evidence that IQ is genetic. That's most of the reason why it's become a taboo area of research. If people were sure it was a waste of time, they'd just tell researchers to go ahead and check. Instead, they taboo it because they're afraid of what it would mean for their view of society if it turned out to be true, which it surely is.

As I mentioned in another thread, your claim that it's not genetic should not be the prior here. That would be like me claiming that people's maximum height being environmental should be the prior. It's just preposterous. Of course physical traits are primarily genetic. The brain is a physical object, therefore its structure is primarily genetic.

Later

You've extensively edited your comment. In response to those edits: if you look back at my comments, I think you'll see that I haven't made a claim about genetic determinism at all, only that the evidence you've presented doesn't support it.

Or in other words, the reason you're not smarter is because nobody's invented a surgery to make you smarter yet. And the reason you're not less smart is that nobody's hit you over the head with a rock. If either of those scenarios happened, your ancestry wouldn't get to object much.

If you want a theory of intelligent to include a notion of general intelligence which can be measured, you must be able to defend which aspects of behavior falls in the category of intelligent, and which not.

Playing chess and jumping on furniture both require plenty of cognitive skills, and brain functions to work together and produce a singular outcome, both are goal driven, both takes years of practice, both have varying skill levels.

Now the cognitive functions these skills require may both be inherited, you may even find the specific genes which encodes either behavior (and name them the furniture jumping gene and the chess playing gene if you will). However when you assign chess playing as intelligent but not furniture jumping, then you’ve made an arbitrary choice, which you need to justify. (You also have the option of not defining intelligence to begin with; which what I personally would pick).

But more importantly, even if you find your justification, you’ve only found one gene of intelligence which inherits, you haven’t found a gene for general intelligence, so you haven’t shown that intelligence is determined by your genes, only the ability to play chess well.

Then when you find all the genes for all behavior you consider intelligence, you still haven’t shown that they co-inherit with each other, that is, you haven’t shown that people with the chess playing gene tend to also have the sudoku solving gene, and the IQ test taking gene, etc. For there to be a single general intelligence, and for this general intelligence to be determined by genetics, than this is what is required. Unless of course general intelligence is a real thing and there is a gene for it which allows you to play chess better than others, solve Sudoku faster than others, answer more questions on IQ tests correctly, etc. But this is a rather extraordinary claim, don’t you think?

I agree with that reasoning! We defined intelligence the way we do because it "works." If jumping on chairs were what advanced modernity, we would test for that instead. And, that too would "work" because it would surely be a marker for people who were likely to be successful in life.

Social sciences aren't going to be able to provide specific answers to your questions in the near term. No, there is no single gene or trait that codes for "intelligence" as we define it. But, that does not mean we can't come up with intelligence tests which correlate strongly with that definition and also correlate strongly with various measures of success in life. Such measures also correlate strongly with society-wide success (measured by a group's progress along the tech tree).

Actually I’m gonna repeat a couple of paragraph from the first post you responded to: https://news.ycombinator.com/item?id=35517130

> Your [faeriechangling] anecdotal evidence of high IQ parents (ugh!) having high IQ children is the same anecdotal evidence that sociologists have been describing for decades that high SES parents have high SES children, and is the main reason for why parents with high SAT scores are likely to have children with high SAT scores.

> What IQ researchers discovered was basically the same thing that Marx described in 1867, class, however the eugenics were no communists, and instead of providing the simpler explanation, that society rewards the ruling elite, and wealth inherits, the eugenics went all conspiratorial and blamed other races for their perceived decline in society.

> As a consequence, social policy resembles the cycles and epicycles of Ptolemy's cosmology. Namely, all manner of social, economic and historical outcomes which are explained parsimoniously by understanding IQ as heritable are instead attributed to a Rube-Goldberg machine of racism, class warfare and the like.

Now I find it interesting you would say this while also believing that “High SES correlates with IQ” and “You're just measuring the same thing, going round and round in circles.”

Now a sibling post goes into why IQ and SES aren’t the same thing, but suppose for the sake of argument that it is. SES is pretty much just a function of wealth, it can be measured by things like your family income, education and occupation, all pretty straight forward. You don’t need constructs such as intelligence, g-factors, you don’t need to do factor analysis to find correlations within massive tests etc. You just take the income, education, and occupation, and you have your SES.

Now, if I were to look for epicycles within a model which predicts “success”, IQ would be a prime candidate here. Nothing predicts you income as well as your parent’s income, the same applies to education and occupation. So if these are the things you’d define as “success”. Or as you put it:

> If jumping on chairs were what advanced modernity, we would test for that instead. And, that too would "work" because it would surely be a marker for people who were likely to be successful in life.

Now ponder this for a moment. What if instead of creating a construct called intelligence and using that as the predictor for this “success” as you call it, instead we allow society to be unequal. That we grant different people different access to things like good jobs, healthcare and education. Now if said society would enforce this limited access by using something we can actually and objectively know runs in families, say money, fame, and valuable assets, that those that have less of these things get less access to the tings which grants you “success”. Wouldn’t we have a pretty good model to predict “success”.

Now leaving aside this thought experiment (and snark on my part) IQ seems like a giant epicycle of you theory of success. Instead of forming our social policies around intelligence, wouldn’t it be better to form them around something we know is a prime cause of hindrance, inequality.

Now you know my political stance here, so I’m not afraid to say: Solidarity among the working class! Eating the rich! Those are the real solutions. Not being gaslit by the wealthy elite that we are stupider then they.

What people want to understand is the preconditions of the high SES status. Not everyone who achieves high SES has rich parents. Take Japanese people in America. They were placed in internment camps in the 1940s, yet today they have substantially higher median incomes than whites. How is this possible?

Ashkenazi Jews faced unimaginable hardship for centuries, yet they manage to have remarkable success. Jews have won 26% of all Nobel Prizes in sciences, more than 100x what would be expected by chance. Arguing that's environmental is just silly. Their environment couldn't have been worse!

Now to your overall political point, I actually disagree there too. I honestly think it's possible that this quarantining of IQ science and cancel culture are looked favorably upon by elites because they know that they preserve the status quo. In fact, policies that embrace IQ and intelligence research would be far more expensive. Rather than pretending an 80 IQ person is going to be able to become a lawyer, society would have to reckon with the hard truth that such a person is probably going to need meaningful monetary assistance his entire life. Accepting IQ would probably mean something like reparations for slavery would actually have to be paid -- not out of some guilt trip, but because many of these folks need the money to keep up in society. And, you're not going to be able to get away with a single lump sum, because they're going to need the help every year.

So, even with an anti-rich ideology, I just don't think your arguments hold water. You're falling for a head-fake. Haven't you ever wondered why so many super-wealthy people embrace liberal politics? This is why.