Association Between Maternal Fluoride Exposure During Pregnancy and IQ Scores
jamanetwork.com
jamanetwork.com
Sure, maybe there's a correlation purely centered around boy's non-verbal IQ scores, but it smells a lot like a "if you look for enough correlations you'll eventually find one".
- Small sample size (601 kids)
- Effect has opposite sign in girls and boys
- Negative association in boys was barely statistically significant
- Positive association in girls barely missed statistical significance
Not to mention we're testing IQ in 4-year-olds.
For example, population IQ is supposed to be 100. So a score of 105 for boys with a 5 point drop would give us the expected result of average intelligence, right?
Seems like that would filter out the lower end of the bell curve, especially regarding drug use.
Probably just the difference between this cohort vs. all Canadians (urban and rural).
(No, I am not a public health professional, to know if their study's design or other research would rule out paternal exposure to fluorine as a cause. However, I have a very strong impression that both public opinion and most medical professionals are strongly sexist about problems with pregnancy and young children - "anything wrong is the mother's fault".)
I think that the more complex a question is, the more important it is for the answers to be decentralized so that we can experiment with many of them. If fluoride does have significant negative as well as positive effects, that's an argument toward removing it from water supplies and making it a choice. Reasonable people could decide that they prefer weaker bones than minds, or visa versa.
Example: https://i5.walmartimages.com/asr/d45b6df1-099b-4568-b2a9-5dd...
What purpose does it serve?
We can all get behind breastfeeding raising IQ (https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736...) but maybe it’s the fluoride in the formula lowering IQ.
It’s not always possible to breastfeed.
[1] https://www.cdc.gov/fluoridation/faqs/infant-formula.html
Again, what purpose does it serve? Babies and toddlers don’t have their adult teeth so it is irrelevant for dental health at that age.
10 years ago I chose to have my kids in a community that does not fluoridate the water because there has LONG been an association with IQ and ingesting fluoride.
But, MOST insanely, fluoride is by all account a medicine, we are one of the ONLY countries in the world that medicates our water supply. Just think about it, why do we medicate our ENTIRE water supply?
There is something terrible behind the fluoridation of the American water supply, I have no idea what but I do know that as a scientist what we are doing makes no sense and is VASTLY more harmful then beneficial.
Findings -- In this prospective birth cohort study, fluoride exposure during pregnancy was associated with lower IQ scores in children aged 3 to 4 years.
Meaning -- Fluoride exposure during pregnancy may be associated with adverse effects on child intellectual development, indicating the possible need to reduce fluoride intake during pregnancy.
this reads like cherry-picking to me.
The irony being that tons of social science academics desperately want to prove IQ is bunk and become famous for it, but their failures just keep proving it's legitimacy. If only they tried so hard to disprove their own pet theories
In fact, most of the continuing proponents for IQ testing take the stance of "We don't have anything better, so we will use it even if it's deeply flawed." This viewpoint is so prevalent that a majority of studies on the subject in the last 10-15 years are skewed towards evaluating alternative testing methods.
Here's a small sample of studies showing the different reasons IQ tests fail to measure intelligence:
1. [Fractionating Human Intelligence](https://doi.org/10.1016/j.neuron.2012.06.022)
2. [Commentary on the pitfalls of IQ test standardization in multicultural settings](https://doi.org/10.1080/13854046.2016.1204011)
3. [What IQ tests really measure.](https://doi.org/10.1037/0033-2909.101.2.171)
4. [The Evils of the Use of IQ Tests ... In First and Second Language Learners](https://www.jstor.org/stable/20205010)
You can differ as much in your test-retest score as would be the gap between mental retardation and "normal".
Above 100, they're mostly a measure of proficiency at taking written tests.
In any case, there is no theory of what IQ measures other than by assertion that it measures "intelligence", so there's nothing actually to be said about it.
It's a means of extracting apparent patterns in some test answers; there is no scientific theory of what those patterns mean.
Given that this is what we are attempting to measure, it seems completely fine. Pointing out flaws in the test (lack of generality, non-deterministic behavior) is not actually a counter-argument so long as the test correlates with at least some outcomes that we care about.
And it does! And this is very reproducible!
The claim that IQ tests are "cognitively difficult" is either trivial or unevidenced. Its trivial in the sense that most tasks are "cognitively difficult", that doesnt make them valid measures of cognitive difficulty. It is unevidenced in the sense that there is no theory of what "cognitive difficulty" means that can be tested.
My apologies, but IQ tests really are actually pseudoscience. They're a product of a discipline which superstitiously uses GUI-statistical tooling without understanding anything abotu the scientific method, nor the statistical metrics that these tools report.
An animal, and its intelligence, is a complex chaotic system whose "cognitition" or "intelligence" is by no means measured by an IQ test. And such a claim is prima fascie ridiculous from any actual biological (ie., theory-building, scientific) study of intelligence.
Can you point to all of the scientists, engineers, and mathematicians with IQs under 80?
Even if IQ is meaningless, this result is still evidence of neurological harm.
IQ measurements have strong predictive power too for various outcomes, such as educational attainment.
A civilization reduction of IQ by nearly 1/3 sigma is absolutely cause for concern.
IQ only has predictive power at very low scores; above 100 it randomly correlates with, eg., wealth and various other extrinsic objective measures.
The only cases where "success" is measured by the profession are circluar, ie., its often claimed Drs/lawyers etc have high IQs, but necessarily so, since they're all filtered based on IQ tests.
Psychometry has nothing to replicate, because there are no psychometric theories. It is simply a field which finds patterns in exams it makes up, based on no testable theories, and asserts that these patterns have "some meaning". There isnt anything here to replicate.
In reality, intelligence is the single most selected for human trait and it correlates with, to a greater or lesser extent, being better at basically everything. In other words, it has many phenotypic consequences. That includes some pretty surprising things, like semen quality[1] and height[2]. And then there's the obvious stuff like higher IQ correlating with better performance in school and work[3]. It also correlates with higher income and lower criminality, but those effect sizes are smaller.
[1] https://www.researchgate.net/publication/222683944_Intellige...
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3617178/
[3] https://en.wikipedia.org/wiki/Intelligence_quotient#Social_c...
A vast amount of "mere statistical" research is pseudoscience; entire fields. It requires a lot of experience in hard scientific methodology, and an actual education in statistics. A lot of experimental sciences attract people interested in the experiments who just plug data into models and report the results.
The vast majority of such "research" is pseudoscience, and it's one massive house of cards. Most "heritability" research, population genetics research, psychometrics, psychology, nutrition, etc. is pseudoscience.
The whole type of statistics that has basically been invented by the social sciences is the basis for massive amounts of pseudoscience. Factor analysis, propensity scores, correlation coefs, etc. -- it's just an analysis of correlation.
Such is the poverty of thinking in these "social sciecnes" that they arent trained enough to realise that a model of correlations in effects isnt a model of their causes, not even nearly so. And this is esp. sevre in the case of complex systems like humans and animals.
All of the methods of IQ research are simple models of correlations in quiz answers. They do not rise to the level of a theory of anything, and their use is routinely circular and unethical.
Yes there is a replicability crisis in much of the social sciences. Yes cargo cult science[1] has been a real problem and continues to be. Nevertheless there isn't a replication problem for psychometry. Countless researchers have dedicated their careers to showing that there is, and yet they have all failed to do so. I agree though there is room for improvement. IQ is only a model and we're measuring a proxy for intelligence, not intelligence itself. Still, it's a pretty good proxy, just as grip strength is a pretty good proxy for overall physical strength.
There is also high quality replicable research in all those fields you disparage. For example, generally speaking, metabolic ward nutrition research is of high quality.
The argument is just, "I rekon intelligence has something to do with quizes like this, and look, there are correlations in people's answers!"
That's the premise of the entire field. It doesnt have a theory of intelligence, and any even plausible scientifically-grounded theory of intelligence would pretty clearly invalidate IQ as a measure of it.
HN isnt a place to give a lecture course on statistics, causal modelling and the scientific method. But the vast majority of people I'm aware of with serious work in those areas, regard this entire field as pseudoscience. It is only researchers within this field who believe otherwise, and they arent professionals.
Is your claim now that there is no such thing as intelligence? If we accept that premise then sure the whole field is bunk, because you can't measure something that doesn't exist. However I consider such a claim as ludicrous as saying that there is no such thing as strength, so if that's your position then I don't think I have much to learn from you.
Meanwhile, the g factor[1] is a theory of intelligence that basically says people who are good at one kind of cognitive task will also be good at other kinds of cognitive tasks. Is that entirely satisfactory? I've already said there's room for improvement. Nevertheless we have to start somewhere, and given the complexity of the array of phenotypes we associate with intelligence the g factor isn't a bad start.
> any even plausible scientifically-grounded theory of intelligence would pretty clearly invalidate IQ as a measure of it.
This sounds like an easy claim to support. Since you are enthusiastically anti-psychometry I assume you've done the research. What do you mean by "plausible scientifically grounded?" Would you please give a supporting example?
> HN isnt a place to give a lecture course on statistics, causal modelling and the scientific method. But the vast majority of people I'm aware of with serious work in those areas, regard this entire field as pseudoscience. It is only researchers within this field who believe otherwise, and they arent professionals.
HN is a place for satisfying intellectual curiosity. You would be contributing to the site's reason for existing by giving an abbreviated lecture actually showing that you have a point rather than just appealing to unknown authorities.
However, to succeed at higher education (and to get into it), especially written tests, you need to be good at some stuff that also means you'll be decent at an IQ test. That means they have some value, though I tend to agree that it means very little overall.
Apparently in other places, doctors and lawyers literally take an IQ test, which is bizarre.
Or maybe the original poster has an unusually broad understanding of what's an IQ test, in that pretty much any (written?) examination qualifies. Which would transform his thesis from "IQs are a sham" to "any evaluation of specific aptitude and knowledge is a sham".
He's apparently referring to the MCAT and LSAT, which serve as entrance examinations for medical and law schools respectively.
Similarly the SAT, which is the undergraduate entrance examination used by many schools, is a very good predictor for score on an actual IQ test. So much so that one can conflate the two without really being very wrong.