I've had increasing trouble reading books for years. It stresses me out, I can't just sit for hours reading, I have things to do. It takes real... something - focus, mindfullness - to actually sit down and think in an explorative way that isn't strictly driven by work.
This isn't that surprising. IQ tests a specific type of intelligence, and we probably don't leverage that sort of intelligence day to day. Instead, we create hyperfocused individuals and build structure and process around them so that they can collaborate. Being generally intelligent and having general problem solving skills is less and less important, or at least we treat it that way.
Most politicians are exasperatingly dumb, most celebrities are witless mannequins and the richest man in the world is a simple minded moron that acts like a 16yo in the middle of a sugar rush. Don't blame the youth for not wanting to be "smart" when they can see that plenty of mediocre adult content creators can earn more in a week than your average office worker in a month and when their role models are dudes vlogging about getting rich gambling on JPG monkeys and shilling for crypto rug pulls.
> What specific environmental factors cause changes in intelligence remains relatively unexplored.
What might these factors possibly be? Some candidates I am aware of, that are known to affect IQ: heavy metals in infant formula , increases in baseline CO2 levels , stress , deficiencies caused by soil depletion . Leaded gasoline seems to have been ruled out by timing.
It's interesting to me that this started in 1975 and is observed across Europe. Do we know of any major changes in habits or industrial practices that started around that year?
The increase could be due to improved nutrition following WW 2, such as better access to food overall and the iodization of salt.
For the decline, my money is on PFAS (https://www.sixclasses.org/videos/PFAS) and organohalogens more generally. Iodine is also a halogen, and all the other halogenated compounds we are pumping in the environment could interfere with iodine metabolism. These compounds are in nearly everything, and we're using ever larger quantities of them.
There is evidence this affects fetal development and cognitive functioning years later (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2799472/), which is also why jurisdictions are banning flame retardants (https://www.tuvsud.com/en/e-ssentials-newsletter/consumer-pr... https://www.sixclasses.org/videos/flame-retardants )
The article didn't link data so I can't dig in further.
Given fertility is negatively correlated with intelligence, and how hereditary IQ is, it's just a matter of time until IQ declines.
This is not so shocking, how many kids does your typical college professor have before 35, is it 0 or 1?
And while IQ is not too much related to education, we let kids do what ever, when ever for a so call peace of mind, so yeah a kid who is never challenged can't have broad skills. I would dare to say that video games are saving IQ scores but for all the wrong reasons (fast pattern recognition and spacial movement related tests).
Statements like this have always made me question these tests. Ten points in IQ represents a movement of one standard deviation in intelligence. To believe the quote above would mean that there was a massive increase in intelligence between the 1960's and the 1990's. But an increase of one standard deviation across any trait at a population level is very very unusual, and likely would have been noticed long before any studies were conducted.
Put another way, do we really believe that someone with slightly below average intelligence in 1962, say an IQ of 85, is the intellectual equivalent of someone with a significantly below average IQ (e.g. 75) in 1990? An IQ of 75 typically means you're not in public school or if you are, you're in Special Ed.
(1) Physical fitness. These same years have seen the explosive growth of obesity and related lifestyle diseases. A greater percentage of people in first world countries (and increasingly elsewhere) are either obese or overweight. I recall reading that one way to keep your mind sharp is to be physically fit (cf: "Spark: The Revolutionary New Science of Exercise and the Brain" by Ratey and Hagerman). The corollary could be that if you are not physically fit, your IQ will suffer.
(2) Pollution. Air pollution has been shown to affect IQ scores (https://www.unep.org/news-and-stories/story/air-pollution-li...). It could be that greater pollution has been causing lower IQ scores.
(3) Sleep. I recall reading that people get lesser high quality sleep than they used to. It has very clearly become easier to stay up late today. Poor sleep is really bad for you for a number of reasons, including your cognitive performance and brain health.
I can think of a multitude of reasons younger siblings should, on average, have a lower IQ than their older brothers. Could this independently account for the 'decline' that researchers are measuring?
Leaded gas wiped nearly 10 IQ points off of everyone and is still used in general aviation.
...or maybe, it just improves your test-taking ability?
The one thing that stands out is that the sample population comes from Norwegian Military conscripts. Since the end of the Cold War militaries have contracted across NATO and Western Europe. I would be curious anyone from Norway could comment on whether there might be a fundamental shift in the data. If a lot of smart kids avoid conscription by going to University somewhere then the results of these tests ought to trend downwards.
That sounds weird. Doesn't that mean they're "measuring intelligence" wrongly, as plenty of people without extensive formal education are extremely intelligent?
eg those same people getting further formal education may indeed score higher on these IQ tests, but the education is in no way changing the persons IQ
That's is. If we teach from the early childhood we nourish intelligence, if not we nurtured stupidity. The rest might matter to a certain extent but it's mostly background noise.
The study focuses on “two brothers” cohorts and makes the claim that iqs within families are on the decline, but fails to adjust for confounding factors, like the selection bias inherent in their cohort selection process.
Other studies show that first borns have a higher iq than later siblings, and to a greater extent than what this study found!
Iq isn’t boosted by higher education. This isn’t up for debate. Outside of malnourishment and sensory deprivation it it mostly heritable.
> TruTV’s Adam Ruins Everything is known for debunking accepted wisdom. It took less than two minutes to demolish IQ tests:
Perhaps specific areas could be tested, such as memory - but even with such a basic concept, we know that the ability to memorize a long string of numbers is a highly trainable skill. If we go to 'higher level' mental processes, such as pattern recognition, symbolic interpretation, analytical capabilities (i.e. higher maths), and creative capabilities (inventiveness), again we see that these abilities are highly trainable.
The only real way to sort this out would be to apply the same educational program to a large cohort of individuals, over the course of at least a year, involving intensive one-on-one tutoring, and administer the prospective IQ test both before and after this process takes place. This has come up before and such a study has never been done to my knowledge, nor has anyone ever pointed one out.
Is there a method to dumb yourself down? asking for my smart friends
Not surprising that they succeeded doing that.
So I can't really take into high consideration inference based on average IQ test results. It could also mean that people are becoming intelligent in stuff not measured by the test. I really don't know.
Another point to consider: even if we had the perfect way to measure intelligence, so what? Why waste an intelligent person time doing a test about intelligence? What does this accomplish?
If the number doesnt have any rigorous meaning then who cares if it changes, up or down, could mean anything.