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IQ scores are falling and have been for decades (2018)

• contravariant 4y ago
  Anyone with some domain knowledge willing to pitch in whether it's correct people are equating IQ with education in this thread?
  • annyeonghada 4y ago
    Here[1] there's a summary of the evidence for and against IQ. [1]https://www.reddit.com/r/slatestarcodex/comments/oh6115/performance_on_standardized_assessments_of/ https://www.reddit.com/r/slatestarcodex/comments/oh6115/perf...
    • mrtranscendence 4y ago
      All that verbiage and the best he can do with respect to establishing causality is an offhand remark that causality is “heavily implie(d)”. Controlling for confounders won’t necessarily recover estimates of causal impact. At the least I’d like to see something like an instrumental variables analysis.
  • Out_of_Characte 4y ago
    From what I've read is that IQ is largely genetically determined, With all the complexities that genes bring with them. And its very hard to increase intelligence in a meaningfull way. But whats important is that its very easy to make someone really really dumb. Like the disaster that was leaded gasoline causing an estimated loss of 2 to 8 iq points on a test. Education absolutely increases IQ test scores but wether its an increase in intelligence itself whatever that may be is questionable.
    • SyzygistSix 4y ago
      A guess is that quality education, like encouraging the curiosity to read and tinker, has a bootstrapping effect.
    • kazinator 4y ago
      An IQ test cannot distinguish between a subject who originally came up with a problem-solving technique due to innate intelligence, and one who has already seen that type of problem and learned the problem solving trick from someone else (possibly from having challenged numerous IQ tests). There is some alignment between IQ tests and academic work; an academic background gives you a few tricks for solving those kinds of problems.
    • amusedcyclist 4y ago
      It all depends on how define intelligence, If by intelligence you mean the ability to reason about and solve complex problems then education definitely improves intelligence. However, if you choose to define it as something innate then by definition education does not change that. I think the former is a far more useful definition, its more important what a person can actually do as opposed what they could do in some hypothetical world
      • Out_of_Characte 4y ago
        The problem I see is that intelligence is at large innate, someone with a 110 IQ bracket can't realisticly retest at an IQ of 140 unless you're training purely on IQ tests. This puts a severe upper bound on what anyone can 'solve trough education' as someone with a first tested IQ of 140 requires zero education to achieve a retest of 140 AND has the ability train or educate themselves even further. The IQ test itself is as real of a problem someone can solve as any other hypothetical problem. So if you choose to define intelligence by education, then you're still selecting for innate intelligence plus someones work ethic. Which to me is silly because the education system itself already selects for that and IQ tests are carefully designed for innateness which is why retests or learning for an IQ test bars you from a valid score. I'm sure Intelligence is somewhere inbetween but we can barely solve for one variable at a time.
  • derbOac 4y ago
    So the Flynn effect (rises in IQ to a certain point in time) has been demonstrated in many many many cultures with many tests, many of which are difficult to explain in terms of formal western education. Like nonverbal pattern recognition tests given to traditional tribes in jungle areas. It's one of the mysteries about the Flynn effect and why it's so difficult to explain. It's also not just the case that the "bottom is being raised", but also that the whole distribution was shifting. I think these kinds of things make it unlikely education is explaining at least the rise part of the curve. To the extent the fall is in a subset of these types of measures of settings it also might not be (but it could be). The more recent decline has been less well-documented although there are multiple studies using multiple measures that have shown this, so I believe it is a trend at least in some regions of the world (developed, western). I have a fuzzy memory that the decline is stronger with verbal measures (as opposed to nonverbal) but I might be misremembering that. Education is strongly related to IQ/g/general cognitive ability but they're not perfectly correlated. I think when I looked this up a week ago or so, the best estimates were like 0.50 in a general population sample. Clinically a discrepancy between IQ and educational achievement is important, as it points to someone not getting resources they need etc. So yes, they're related, and yes, education could explain general population trends over time, but no they're not the same.
  • PopAlongKid 4y ago
    I just read this passage from the short story "Flowers For Algernon": "I'm not sure what an I.Q. is. Dr. Nemur said it was something that measured how intelligent you were--like a scale in the drugstore weighs pounds. But Dr. Strauss had a big argument with him and said an I.Q. didn't weigh intelligence at all. He said an I.Q. showed how much intelligence you could get, like the numbers on the outside of a measuring cup. You still had to fill the cup up with stuff." Maybe that stuff is education.
• seydor 4y ago
  I know mine has
• zone411 4y ago
  Covid won't help: https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(22)00147-X/fulltext https://www.thelancet.com/journals/eclinm/article/PIIS2589-5....
  • tjpnz 4y ago
    That study focuses on the severe end of the spectrum but I've also read that just getting it (even if asymptomatic) may have a longterm impact on the brain. That's grim, even more so given how many now consider infection to be an inevitable part of life.
• fastball 4y ago
  Idiocracy a documentary?
  • SQL2219 4y ago
    Brawndo is the environmental factor at play.
  • staticassertion 4y ago
    > “It’s not that dumb people are having more kids than smart people, to put it crudely. It’s something to do with the environment, because we’re seeing the same differences within families,” he said. > The study not only showed IQ variance between children the same parents, but because the authors had the IQ scores of various parents, it demonstrated that parents with higher IQs tended to have more kids, ruling out the dysgenic fertility theory as a driver of falling IQ scores and highlighting the role of environmental factors instead.
  • underwater 4y ago
    That movie really missed the mark. It made out like the dumbing down would be a result of generations of poor breeding. Instead we see the dumbing down has been due to people willingly thumbing their nose at science and reason.
    • marginalia_nu 4y ago
      The backlash against science is fairly reasonable, given how often science is misrepresented and how often preliminary findings are reported as facts, often in some misguided attempt to help make it easier for people to understand. People pick up on the discrepancies, and overstating our confidence early makes it look really bad when it turns out that the results were incorrect. The Covid pandemic is a great example of this, a lot of extremely sketchy and highly preliminary studies were misrepresented as certainties. It takes many months to produce a solid scientific study, sometimes even years. Yet here we were, a month into the pandemic inundated in studies that simply could not be solid. But they sounded scary, so they made the news. This created the appearance that science kept contradicting itself. One week the virus had a 40% mortality rate, and then next it had 0.1%. What gives, science? The basic posture of science is "I don't know". If you gloss over that fact because it's scary when science doesn't have answers yet, then what you are communicating isn't science, it's something else, speculation, the party line, I dunno. Overall the fundamental problem is a basic lack of faith in grown adults to make their own judgements, and a willingness to simplify the message so much that it no longer is good science. If you don't let people be adults, they will be children instead. That is exactly where we are right now.
• bretpiatt 4y ago
  The analytical side of me doesn't understand how scores on a test that baselines the average to X (in the case of IQ, it is baseline of 100), then distributes them around that baseline on a normal distribution curve can go down over time. The article didn't link data so I can't dig in further. https://personalityanalysistest.com/iq-score/what-is-the-standard-deviation-of-iq-scores-guide/ https://personalityanalysistest.com/iq-score/what-is-the-sta...
  • Naga 4y ago
    The article linked the study though: https://www.pnas.org/doi/10.1073/pnas.1718793115 https://www.pnas.org/doi/10.1073/pnas.1718793115
    • bretpiatt 4y ago
      Thanks, missed the link, reading study. So many variables here including way the math portion was measured moving to multiple choice in the 1990s when the scores start dropping, hopping on a flight, still skeptical. Other quick one, all 95% confidence interval on data that moves less than +/- 2.5% either way. I understand confidence interval isn't a straight linear margin of error, it one I'd want to also look at further.
  • zone411 4y ago
    The most of obvious way would be to use the same test as previously and just compare the scores.
    • throwaway6734 4y ago
      Isn't it possible that changes in education style or focus could bias scores?
      • esja 4y ago
        The first step is to run the same test. The second step is to work out why the results are different (if they are), which might include teaching styles, focus issues, malnutrition, or many other things.
• lbj 4y ago
  Great to finally have some data. The tendency has been pretty clear for some years now, with more and more crazy ideologies spawning among the young.
  • barry-cotter 4y ago
    “Our sires’ age was worse than our grandsires’. We, their sons, are more worthless than they; so in our turn we shall give the world a progeny yet more corrupt.” Book III of Odes, Horace circa 20 BC “Modern fashions seem to keep on growing more and more debased … The ordinary spoken language has also steadily coarsened. People used to say ‘raise the carriage shafts’ or ‘trim the lamp wick,’ but people today say ‘raise it’ or ‘trim it.’ When they should say, ‘Let the men of the palace staff stand forth!’ they say, ‘Torches! Let’s have some light!’” Tsurezuregusa (Essays in Idleness), Yoshida Kenkō 1330 – 1332
• skozharinov 4y ago
  Isn't IQ designed to average at 100?
  • xupybd 4y ago
    Yeah I'm pretty sure that's the definition of the test.
  • kube-system 4y ago
    Yes, after it is adjusted. But the average performance of the test groups have changed over time.
  • rightbyte 4y ago
    The test is graded to a curve with 100 as middle and usually 15 points SD. Size of the SD might vary.
• staticassertion 4y ago
  Higher education has never been a worse investment. There's so little time or incentive to read, and it's hard to sit down and say "I'm going to read a book". It's hard to read a book and also watch tv and also talk to friends etc etc, but that's how we spend all day - constantly interacting with media or socially. 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.
  • pojzon 4y ago
    > Being generally intelligent and having general problem solving skills is less and less important. TBH looking at how the future is going to look like (no not utopia), those general skills seem to be more and more important on the contrary. Being “too specialized” will hurt society in the end.
    • antihero 4y ago
      Division of labour has been a tool to make us dependent on the system and our overlords. People like Kropotkin have been saying this for quite some time.
      • tomrod 4y ago
        Darn that eusocial evolutionary pressure!
      • CryptoPunk 4y ago
  • BlargMcLarg 4y ago
• deleted 4y ago
  [deleted]
• kybernetyk 4y ago
  Regression to the mean.
  • bigbacaloa 4y ago
    Regression to the moron.
  • seydor 4y ago
    regression of the mean
• thret 4y ago
  Is this attributable to leaded gasoline? https://en.wikipedia.org/wiki/Thomas_Midgley_Jr https://en.wikipedia.org/wiki/Thomas_Midgley_Jr. "Use of leaded gasoline, which he invented, released large quantities of lead into the atmosphere all over the world. High atmospheric lead levels have been linked with serious long-term health problems from childhood, including neurological impairment"
  • staticassertion 4y ago
    Lead poisoning disproportionately affected those born between 1950 to 1980 and have significantly dropped in the last 20-30 years. So I don't think so.
    • andrew_ 4y ago
      I believe you're neglecting the cascade effect. If those people had children (they did) then their emphasis on education and the kind of rearing for children that encourages more intelligence was surely effected.
      • staticassertion 4y ago
        Sure, I'm willing to buy that it's related, but it's going to definitely be tertiary effects and not that the population is poisoned.
• notahacker 4y ago
  So two hypotheses: Generation X was a generation of unparalleled genius effortlessly surpassing their idiot ancestors before who merely built the modern world and their children who merely consumed and produced vastly more written content than ever before whilst playing with increasingly complex abstractions on computers, or IQ test comparisons between dissimilar populations don't really mean very much, because the "quotient" is a ranking mechanism for solving a certain type of paper puzzle, not an actual thing.
  • jakobnissen 4y ago
    Luckily, we can easily test how much IQ matters by looking at the relationship between IQ and health, wealth, educational achievement and so on. And it turns out that IQ mean quite a lot, no matter which way you believe the causality goes.
    • notahacker 4y ago
      The apparent peak IQ generation consistently scores lower than later generations on age-adjusted measures of health, wealth, educational achievement etc though. The fact that IQ test scores are somewhat useful as a ranking mechanism amongst a cohort is completely consistent with it being just being a collection of standardised tests calibrated to score in a particular way, not an actual "thing" where apparent subtle generational changes might represent genuine changes to our physiology or intellectual potential and not just inconsequential differences in our preparedness to solve paper puzzles.
  • istinetz 4y ago
    >the "quotient" is a ranking mechanism for solving a certain type of paper puzzle, not an actual thing. Sure, except it strongly correlates with pretty much every single measure of fluid intelligence you can think of. And with a billion real life outcomes, besides. It just so happens that the best statistical distillation of intelligence measures happens to take the form of "paper puzzles". We can, I guess, do a 12 hour barrage of 50 different intelligence tests, but what's the point, when one does the job. >So two hypotheses There are plenty of other hypotheses.
• Foobar8568 4y ago
  In france, kids in the 50s could write with a nib/ink by 6, before starting primary school. We are lowering our education requirements since the 70s. Basically since the rise of "international governing education", see failure modern maths and global reading. 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).
  • ddanv 4y ago
    You don't play the correct video games. See puzzles and be puzzled :)
    • FredPret 4y ago
      Perhaps only the hackernews crowd plays the interesting games
  • dj_mc_merlin 4y ago
    The French education system has always been needlessly tough on kids. I went to a European school with many nationalities mixed in (each with their own section), and the poor French were overworked to hell and received lower grades than us anyway. Each teacher viewed this as normal and said that in France it would've been even harder. None of the French were especially smart because of it though, so I have no clue why they were doing it. Sadism? So in my mind it's a welcome change.
  • xornox 4y ago
    In Finland, everybody and your mum has ”higher education”. Requirements are surely decreasing. Old academic universities are now vocational schools.
• everyone 4y ago
  I thought IQ tests were pseudoscientific anyway? If the number doesnt have any rigorous meaning then who cares if it changes, up or down, could mean anything.
  • BlargMcLarg 4y ago
    IQ tests can be trained for and gamed, at the very least.
    • ryan93 4y ago
      no one does. there are orders of magnitude more studying for the SAT and studying for the sat has a marginal benefit for many
      • BlargMcLarg 4y ago
        Europe doesn't use SAT. I concede most people don't actively train for IQ tests, especially not people who only have to do it once. But one can't exactly claim "IQ tests are flawless measures of IQ" when they can be trained and gamed, which is the point.
        • ryan93 4y ago
          But the scores that psychologists use in their studies weren’t collected from people who trained for the IQ exam. Almost impossible to find out what they ask on exams since they are sold directly to practitioners.
  • xupybd 4y ago
    They're a good proxy for abstract ability.
  • jjgreen 4y ago
    They're a great measure of intelligence -- if you believe in them, you're an idiot.
  • annyeonghada 4y ago
• lrvick 4y ago
  I blame smartphones. Really I do. My overall ability to focus and consume longform content has gone up dramatically since ditching my phone several months ago.
  • nottorp 4y ago
    You don’t need to ditch the phone. Just disable all notifications and maybe uninstall some content consumption feeds like FB or twitter. A phone is what you make of it.
    • bowsamic 4y ago
      Then I spend too much time on HN
      • Snowworm 4y ago
        Maybe set time limits then. Also have an alternative thing to do on your phone if you can't do anything else (like Duolingo or respond to important emails).
      • tintedfireglass 4y ago
        Do you spend time on HN or waste time on HN. If it is spend then it is not a problem.
  • joachim4 4y ago
    Greyscale and no social media did reduce my smartphone consumption a lot. And consulting Instagram / Reddit only on a computer is not a death in itself (plus I use Intention [1] to keep my time on those websites in a normal range. [1] https://chrome.google.com/webstore/detail/intention-stop-mindless-b/dladanhaondcgpahgiflodhckhoeohoe?hl=en https://chrome.google.com/webstore/detail/intention-stop-min...
  • mrtranscendence 4y ago
    I’m inching closer and closer to just deleting every app on my phone and tablet except what allows me to take calls, answer emails, and read books. I read so much when I was a kid, with a great deal of focus, but now I feel like I need constant shifting multisensory stimulation. I can hardly get through ten minutes of a movie without pausing to look at my phone. I can’t listen to a podcast without playing a game or something at the same time. I absolutely feel that I’ve gotten dumber in the last fifteen years.
• Simon321 4y ago
  This is from 2018 to be clear.
  • flint 4y ago
    ^Should be top comment.
• HL33tibCe7 4y ago
  I wonder whether we need to take another look at our modern school education system. Maybe some of the things we (rashly?) ditched had some importance that we didn’t realise at the time. Like learning poetry by heart, learning multiplication tables, “old-school” teaching methods that have now fallen out of favour.
• 8bitsrule 4y ago
  IQ alone got us Skinner and H-bombs. If EQ has gone up, that's a win.
  • andrew_ 4y ago
    EQ is considered by some to be a bit of a cult https://www.inc.com/quora/its-time-to-stop-talking-about-eq-because-it-doesnt-actually-exist.html https://www.inc.com/quora/its-time-to-stop-talking-about-eq-...
  • seydor 4y ago
    EQ is definitely up. It got us twitter
• PeterWhittaker 4y ago
  While causal factors are not identified, the study ([1]) concludes that the decline is due to environmental factors, and neither to genetics nor to other family-related causes. [1] https://www.pnas.org/doi/10.1073/pnas.1718793115 https://www.pnas.org/doi/10.1073/pnas.1718793115
• torginus 4y ago
  I wonder if there is a negative impact produced by people having kids later in life - the reduced sperm and egg quality must play some role in this.
  • ausbah 4y ago
    as you get older its harder to have kids, but that doesn't make the kids worse off
    • hedora 4y ago
      It definitely makes the kids worse off. The reason it's "harder" is because the number of complications/birth defects increase exponentially over time. In a few years after age 40, the odds cross from "negligible" to "don't have kids".
• justinclift 4y ago
  > Access to education is currently the most conclusive factor explaining disparities > in intelligence, according to Ritchie. 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
  • snowwrestler 4y ago
    Imagine two people own farms. One has very rich soil, full of nutrients, ready to grow amazing crops. The other has thin depleted soil, barely able to support plant life. The farmer with rich soil has the opportunity to out-produce the other one, but only if he works the land. And the harder he works it, the more productive he will be (up to a point). Or think of top athletes. Only a few people have the inborn talent to become Olympic champions. But no one becomes an Olympic champion unless they work hard—no matter how talented. Heritable intelligence is best thought of as a potential. Education can increase a person’s IQ scores for the same reason that working out can increase a person’s athletic performance. We don’t have a way to directly measure inherited potential in people; we can only measure what they do. Even an IQ test is based on what people do as they take the test. But also the idea that intelligence is fixed at birth does not align with what we know about brain development. We know the brain develops through early adulthood, and that different life experiences result in physically different brains. While inheritance may put a top-end limit on how intelligent someone can become, it does not necessarily fix intelligence precisely on the IQ scale at birth.
• walkhour 4y ago
  The article insists several times this is not due to genetics, because people with lower IQ don't have more children. This is not true[0]. What the article may want to say is that it's not due exclusively to genetics. 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? [0] https://en.m.wikipedia.org/wiki/Fertility_and_intelligence https://en.m.wikipedia.org/wiki/Fertility_and_intelligence
  • dqpb 4y ago
    It also begs the question, who’s really more intelligent? The person who spent their prime years pontificating, or the person who won the evolution game?
    • throw_m239339 4y ago
      > It also begs the question, who’s really more intelligent? The person who spent their prime years pontification, or the person who won the evolution game? You're right, who's smarter? The people who manage to reproduce thus pass on their genes or the ones that are "too smart" not to?
      • zo1 4y ago
        You could say they're winning, but they are essentially abusing the good-will of society by imposing the care of their offspring onto society instead of caring for them themselves. It may sound bad, but in my mind, purposefully bringing children into the world without security to care for them seems immensely evil and selfish.
        • dqpb 4y ago
          Don’t hate the player, hate the game.
          • 4y ago
• nathias 4y ago
  Decades is understating it. The beginning of civilization marks the start of the first downtrend in hominid brain to body ratio. There are a few different theories about why, but I find the systemic one the most plausible. The increase in the complexity of a system comes with a reduction in complexity of the parts.
  • mrtranscendence 4y ago
    And aren’t domesticated animals generally less intelligent than their wild relatives?
    • nathias 4y ago
      yea, that's the second theory, but the timings don't really match, we started self-domesticating a long time before civilization
• batch12 4y ago
  My suspicion is that having direct access to all information has offloaded some of our cognitive capabilities to our devices. Also, making everything political-- and as such being told what to think about every topic doesn't really help us exercise our critical thinking skills. Maybe we need to "use your brain" more- as my dad would have said.
• Gigachad 4y ago
  Are there any credible / non scammy ways to take one of these tests online? I haven't looked much myself but it seemed like they would largely be garbage social media bait, or make you take a long test and ask for money at the end.
• d0mine 4y ago
  It is illuminating that the paper doesn’t mention lead while discussing IQ decline in the recent decades. https://m.youtube.com/watch?v=IV3dnLzthDA https://m.youtube.com/watch?v=IV3dnLzthDA
• andi999 4y ago
  I am too dumb to understand what they actually did. (or too lazy understanding the study on my mobile). Can anyonr explain? I mean the IQ tests were not the same for every batch, right? So how do you milk the result out of the data?
• minihat 4y ago
  >"The study looked at the IQ scores of brothers who were born in different years. Researchers found that, instead of being similar as suggested by a genetic explanation, IQ scores often differed significantly between the siblings." 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?
• rossdavidh 4y ago
  "In a separate study that has not been released, he and his colleagues looked at existing research in an effort to demonstrate that staying in school longer directly equates to higher IQ scores." ...or maybe, it just improves your test-taking ability?
• fedeb95 4y ago
  I always had a problem getting the point of IQ tests. It necessarily makes assumptions on what intelligence is, seems a bit self referencing. It measures how you conform to what a specific group of people think intelligence is... 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?
  • bena 4y ago
    Intelligent people will learn faster. Sometimes without explicit instruction. Just like those with intellectual disabilities, hyper-intelligent children also need special resources. A lot of people want to keep the hyper-intelligent in the same classrooms as the normally-intelligent students as a form of child labor almost. The idea being that the hyper-intelligent children could inspire and help the normally-intelligent. I always like to ask if they would also be amenable to allowing those students with intellectual disabilities in the general classrooms. And the answer is always no, because those students would slow down the classroom. And I ask why can't the normally-intelligent inspire and help the intellectually disabled. And they still don't get it. The distance between the hyper-intelligent and the normally-intelligent is the same as that between the normally-intelligent and intellectually disabled. Any help the normally-intelligent may receive is undercut by the harm done to the hyper-intelligent. They need special resources just as the other side of the spectrum does. But they often get less. And we often have to stretch the definition because while one intellectually disabled child would be enough to allocate resources for special instruction, you need at least 5 to 10 hyper-intelligent children before you're allowed to split them off for special instruction. Intelligence is a trait, just like height. Some people are tall, some short, some average.
    • fedeb95 4y ago
      I share your point on help across all the spectrum of abilities, and I don't think there aren't differences in intelligence. I just question this way of measuring it and that measurement is useful. The IQ test models results with a gaussian distribution, so this should mean you don't have to think about distributing people across classrooms by hand. It's pretty rare to only have a class of intellectually disabled or geniuses all banded together. And to measure height only takes a meter. Pretty straightforward and without biases. The creator of IQ tests seemed to have doubts about the validity of the test, so... (validity, not its reliability)
• aaron695 4y ago
• JaceLightning 4y ago
  The article doesn't mention pollution which is a HUGE contributing factor to lower IQ. Leaded gas wiped nearly 10 IQ points off of everyone and is still used in general aviation.
  • _moof 4y ago
    I see this "GA still uses leaded gas" thing thrown around here a lot. And while it's technically true, what I never see accompanying it are any numbers. Things like how many gallons of avgas are burned over time compared to how many gallons of leaded mogas were burned prior to it being outlawed. Or the results of anyone's blood labs. The other day someone was complaining about lead exposure from being near a small airport. Had they been tested and found to have high levels of lead in their blood? Oddly enough, they didn't say. You'd think if they were that concerned, they'd have the numbers to back it up, but they didn't. I'm not saying leaded avgas is good by any means, but I would very, very much like to see some actual quantification of its effects before we all decide it's some kind of global catastrophe on par with having an active nuclear meltdown in every living room on Earth.
    • throwawayboise 4y ago
      Yeah, while there's no "safe" level of lead ingestion, not only do we not use leaded gas in cars, commercial aviation (with very few exceptions) does not use it either, and the private/general aviation piston-engine planes are emitting it several thousand feet in the air, not at street level around houses and people. We should get rid of lead in aviation fuel, but it's not a substantial source of environmental lead these days.
• Starlevel001 4y ago
  ITT one step away from "IQ is correlated to genetics (and also your race)"
  • SemanticStrengh 4y ago
    Of course there is a genetic factor to cognitive abilities. https://en.m.wikipedia.org/wiki/Sex_differences_in_cognition https://en.m.wikipedia.org/wiki/Sex_differences_in_cognition
• kurofune 4y ago
  Who would struggle to be smart in a society that rewards idiocy and blind alignment to asinine political discourses, a society where the loudest opinion is the only one that matters. Enjoy the permanent state of frustration that being "smart" or "rational" will bring you. 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.
  • yehBut0 4y ago
  • bobthechef 4y ago
  • planarhobbit 4y ago
    Intelligence gives you a choice. You can choose to walk away from this as best as you can and go about your life on your own terms. You aren't guaranteed or given anything else. You may also participate, if you choose. This seems to be a sticking point among high achievers, but you really need to dial back any societal expectations you may have. You’re here for a short time, and you’re given the option of watching the spectacle at your leisure. Enjoy it while it lasts.
    • kurofune 4y ago
      I would like to stress that "high achiever != intelligent". And the choice to "walk away from this as best as you can and go about your life on your own terms" is mainly a money issue and not one defined or solved by intelligence.
      • fao_ 4y ago
• mattwilsonn888 4y ago
  I thought the effect was just localized to this website.
• svantana 4y ago
  The data from the study has a giant elephant in the room: war. The participants are 18 year old Norwegians who were forced to take a military examination. The reason they do an IQ test is to evaluate if they are suited for a more analytic role, such as radar and comms. The peak result is for the birth year 1975, i.e. tests taken in 1993. During the cold war, a soviet attack was a real possibility, but that threat pretty much evaporated in the 90's. I did this exam in 1998 and the general vibe was pretty much: "why are we still doing this?" Few people took it seriously.
  • ChuckNorris89 4y ago
    >During the cold war, a soviet attack was a real possibility, but that threat pretty much evaporated in the 90's It didn't really evaporate, it's happening right now, except not in Norway.
    • eurasiantiger 4y ago
      The Simpsons had it right again.
    • brokencode 4y ago
      At the very least, the perceived threat evaporated.
    • _moof 4y ago
      I'm guessing by your username that you were quite young at the time. But things actually were different thirty years ago.
  • habibur 4y ago
    It's not from one study. From 2nd paragraph of the article. > Similar studies in Denmark, Britain, France, the Netherlands, Finland and Estonia have demonstrated a similar downward trend in IQ scores
    • speleding 4y ago
      If the numbers from other countries also come from the military then the point is still valid. I got tested for conscription in the Netherlands in the 90s and a lot of people were wondering if there was any point to it (conscription was abolished soon after). So I can see an earlier generation of conscripts being much more motivated to do well.
• SemanticStrengh 4y ago
  I believe the effect of Tiktok will be unprecedented
• o_m 4y ago
  co2 levels is also getting higher which have negative impacts on learning and concentration.
• darthrupert 4y ago
  It's because the highest IQ people of the previous generation were almost all hired to find out ways to capture everyone's attention as much as possible. Not surprising that they succeeded doing that.
• BurningFrog 4y ago
  "A single new study shows something scary and/or surprising" is a near certain sign that the conclusion is wrong.
• blululu 4y ago
  The actual research comes from 2018: https://www.pnas.org/doi/10.1073/pnas.1718793115 https://www.pnas.org/doi/10.1073/pnas.1718793115 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.
  • lordnacho 4y ago
    I'm not Norwegian but my guess is the system is much like in Denmark, where officially there is also conscription. The thing is though, it's not taken terribly seriously anymore, and this has probably been a trend since the cold war ended. If you want to avoid getting called up, just about any excuse will do just fine, there's no shame in it at all. My guess is the people who want to avoid it are the kinds of kids who would rather go and study than run around a field at night. Those kids will also tend to have the higher IQs, which will thus vanish from the test set.
• phendrenad2 4y ago
  Why is the best source of IQ information we have "Norwegian military conscripts"? Maybe we should make all politicians take an IQ test, so we get a good sampling of the smartest people at any given point in time.
  • robbiep 4y ago
    IQ is mostly a genital measuring test for anyone who wants to talk about it, I don’t think that’s a great idea.
• dcx 4y ago
  At the time of writing, much of this thread is centered around (a) dismissing the study based on considerations that were ruled out within the article, and (b) dismissing the format and value of IQ tests. Let's set these aside and discuss the open question: > 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 [1], increases in baseline CO2 levels [2], stress [3], deficiencies caused by soil depletion [4]. 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? [1] https://www.legalexaminer.com/home-family/baby-food-lawsuits/why-is-there-a-baby-formula-shortage/ https://www.legalexaminer.com/home-family/baby-food-lawsuits... [2] https://medium.com/wedonthavetime/co2-affects-our-thinking-93c016bcc74d https://medium.com/wedonthavetime/co2-affects-our-thinking-9... [3] https://www.nytimes.com/1983/05/31/science/study-ties-iq-scores-to-stress.html https://www.nytimes.com/1983/05/31/science/study-ties-iq-sco... [4] https://www.scientificamerican.com/article/soil-depletion-and-nutrition-loss/ https://www.scientificamerican.com/article/soil-depletion-an...
  • themodelplumber 4y ago
    Plastics off-gassing in the home, car, and at work comes to mind. It would kind of bridge the gap between habit (shopping) and industrial practice. Though I'm not sure about health or IQ implications specifically.
  • jmclnx 4y ago
    I cannot speak about Europe, but in the US, mid-seventies is when one US Political Party started its war on Education, and that accelerated in the 80s and still on going. So I agree it is lack of quality of free education in the early years of childhood development. Too bad the study did not also look at IQ differences between private/public schools over the same period. By private, I mean the schools that only the very rich can send their children too. Also, I did read somewhere else, a study was also done on increased CO2 and intelligence and found higher CO2 could lower peoples intelligence level.
• kkfx 4y ago
  Intellect need stimuli, education not stereotypical Ford-mode workers formation like neoliberal schools have planted ad any level of the society because is easier to govern Ford-model workers than acculturated Citizens. 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.
• steebo 4y ago
  An environmental cause appears likely, since this trend is being observed in many countries. Both the increase in IQ to 1975 and the drop thereafter could have environmental causes. 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 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/ 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-products-and-retail-essentials/e-ssentials-1-2022/usa-new-york-bans-flame-retardants-in-furniture-mattresses-and-electronic-displays https://www.tuvsud.com/en/e-ssentials-newsletter/consumer-pr... https://www.sixclasses.org/videos/flame-retardants https://www.sixclasses.org/videos/flame-retardants )
  • Mo3 4y ago
    I too believe it has to have environmental causes. I saw a phenomenal documentary a few years ago that went into great detail of how especially pesticides and flame retardants are the most likely cause.
  • dcx 4y ago
    This seems like a pretty good hypothesis. I believe the main source of exposure to PFAS for most people is food packaging (IIRC nonstick pans don't move the needle unless you heat way above the safe range, and you'll smell the coating melting). What is the main source of exposure to organohalogens? I'm seeing information about mattresses, flame retardants, and seafood.
    • steebo 4y ago
      PFAS is in so many common consumer products you might well say "it is in everything." That outdoor jacket you're wearing? Coated in PFAS. Your stain-resistant couch? PFAS. All textiles break and release fibres, and we inevitably end up eating them. And if you are cooking with a non-stick pan, it is a guarantee that you are ingesting them. It doesn't have to be the PTFE itself, the emulsifiers (such as PFOA https://en.wikipedia.org/wiki/Perfluorooctanoic_acid https://en.wikipedia.org/wiki/Perfluorooctanoic_acid) are more volatile and have been measured in food cooked with non-stick pans.
• dash2 4y ago
  This is a really interesting, simple and clever study design and I look forward to reading it. That said, I think there is strong evidence for selection against intelligence at genetic level. The question is more "does it explain the Flynn effect and its reversal", or "is it large enough to have an important effect?" See our paper: https://ideas.repec.org/p/uea/ueaeco/2021-02.html https://ideas.repec.org/p/uea/ueaeco/2021-02.html
• sremani 4y ago
  I think Taleb gets it right about IQ, lack of it is a dis-qualifier and beyond a point after certain IQ score it becomes noise.
• marcusverus 4y ago
  IMO the Idiocracy scenario[0] is a likely candidate for a Great Filter[1]. [0]https://en.wikipedia.org/wiki/Idiocracy https://en.wikipedia.org/wiki/Idiocracy [1]https://en.wikipedia.org/wiki/Great_Filter https://en.wikipedia.org/wiki/Great_Filter
  • karaterobot 4y ago
    The article specifically dispenses with the Idiocracy scenario. > “The main exciting finding isn’t that there was a decline in IQ,” Ritchie said. “The interesting thing about this paper is that they were able to show a difference in IQ scores within the same families.”
• fortran77 4y ago
  Maybe we'll finally achieve equity, where everyone has the same (low) IQ. Wouldn't that be the most ideal situation?
• seydor 4y ago
  There s no use to fret about it. I think nature is telling us that IQ (or intelligence) is not needed. sorry folks you ve been optimizing the wrong thing Is there a method to dumb yourself down? asking for my smart friends
• thriftwy 4y ago
  I'd like to say 'hi' to xkcd with his religious attitude towards Flynn effect and readiness to ridicule others over that.
• juanani 4y ago
• ranprieur 4y ago
  People are becoming smart in different ways and the tests aren't keeping up.
• photochemsyn 4y ago
  IQ tests seem woefully outdated and highly biased at best. As many note, the ability to do well on these tests is greatly increased by practice, as with most testing procedures. The notion that an IQ test is a standalone measure of innate intelligence is not well supported. 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.
  • qiskit 4y ago
    > IQ tests seem woefully outdated and highly biased at best. Maybe in the early 1900s, but not today. > As many note, the ability to do well on these tests is greatly increased by practice, as with most testing procedures. The notion that an IQ test is a standalone measure of innate intelligence is not well supported. Then everyone would score 200+. > 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. Yes. Nutrition, education, etc can help you reach your potential. But there seems to be a natural limit. Not only that, some have a natural talent for it and people have different levels of potential. If you believe what you believe, then why haven't you used your revolutionary knowledge to increase the IQs of people with downs syndrome. All it takes is training right?
    • asdffdsa 4y ago
      If there was sufficient profit for it, I'd quit my job and take an iq test and score awfully low on it because I always do poorly on something the first time I try it (SAT test, tech interviews, etc.). Then, I'd study for iq tests, take ~1,000 practice ones, and score in the top 10%. The iq advocates would be flabbergasted! I managed to increase my iq by several standard deviations: what a revolutionary, miraculous result! Then, I would probably create a startup that would offer the same service to the children of wealthy families who wanted their child to be intellectually gifted. With an annual tuition of $10,000 over 10 years, their child could be catapulted for life into the top levels of life outcomes and live as part of the elite class in America. Enrolling a mere 1,000 students (200 in East bay, 200 south bay, 200 SF, 400 in Northeast) would net a revenue of 100 million dollars. Wait a second, maybe I'm onto something here...
• egberts1 4y ago
  It is probably how CNN works too, but with declining journalistic creedo.
• Arun2009 4y ago
  There are three strong factors that come to mind: (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-linked-huge-reduction-intelligence 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.
• freahsteaksauce 4y ago
  The book I'm reading Weapons of Mass Instruction explains this as being part of the goals of forced schooling as designed by Carnegie and other industrialist to make easier to manage laborers.
  • qsdf38100 4y ago
    You just created an account to say "education bad" ?
• ramesh31 4y ago
  With a global average IQ hovering around 80, it really terrifies me what the future has in store given how manipulable the masses are via social media. The recent Phillipines presidential election is a perfect example. There's a sort of cutoff I've noticed around 85-90 IQ where at or below that, people can simply be spoon-fed whatever form of reality you wish for them to accept. The truth no longer matters when someone's entire reality is shaped by 30 second TikTok videos that are actually just performances masquerading as "POV real life". All of those absurd fake videos we see and laugh at only exist because they work.
  • pessimizer 4y ago
    Colonial powers (not just the US) pour cash and military support into dictators supported by dumb nationalists, with the overt intention of helping them marginalize or exterminate their intelligent populations. And I don't mean that it happens inadvertently, I mean that we actively search for the effective influencers within rising movements happening in countries that we're draining the natural resources from through friendly dictators, and we inform those dictators who we also arm. We're actually breeding for stupidity.
    • lvass 4y ago
      This is a very extraordinary claim and should have really strong evidence. At least I'd want to know exactly what is being done to exterminate some groups. The latest example I know of is Stalin's food redirections. Or are you talking of mass migrations and "replacement genocide"?
• 3qz 4y ago
  It’s because of changing demographics
• tharne 4y ago
  > Norwegian researchers analyzed the IQ scores of Norwegian men born between 1962 and 1991 and found that scores increased by almost 3 percentage points each decade for those born between 1962 to 1975 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.
  • paulpauper 4y ago
    the Flynn Effect is controversial for this reason. IQ tests are still useful of assessing and predicting individual differences of ability.
  • deleted 4y ago
    [deleted]
• paulpauper 4y ago
  Interesting...could this explain secular stagnation?
• tls 4y ago
• mc4ndr3 4y ago
  PFAS
• ParetoOptimal 4y ago
  Aren't IQ tests basically BS? > TruTV’s Adam Ruins Everything is known for debunking accepted wisdom. It took less than two minutes to demolish IQ tests: Quote: https://www.insidehook.com/article/history/charles-darwin-spawns-much-pseudo-scientific-racism https://www.insidehook.com/article/history/charles-darwin-sp... Video: https://youtu.be/W3oUqKUx2o0 https://youtu.be/W3oUqKUx2o0
  • gruez 4y ago
    >Aren't IQ tests basically BS? Depends on what your starting premise is. If you start out with a strawman like "IQ fully captures a person's intelligence", then yeah it's "BS". At the same time, if you're arguing that IQ tests are "BS" (ie. no value whatsoever), then that's also false, see: https://en.wikipedia.org/wiki/Intelligence_quotient#Social_correlations https://en.wikipedia.org/wiki/Intelligence_quotient#Social_c...
• jmpman 4y ago
  Brawndo has electrolytes.
• willmadden 4y ago
  This is a garbage CNN article about a laughable iq study that’s so bad it borders on propaganda. 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.
• yarg 4y ago
  No, they aren't - and by definition (IQ across the population has a fixed mean and standard deviation).
• hitovst 4y ago
  Forced redistribution of wealth is dysgenic, and there is no single greater indicator for success in life than IQ.
• bhouston 4y ago
  I suspect it is partly environmental pollutants.
• twoxproblematic 4y ago
• chris-orgmenta 4y ago
  I suspect that long-term benzos, alcohol and/or marijuana use is contributing to this to a significant degree. Would be interesting to see data on this.
• egberts1 4y ago
  Check the background d of the two authors of the original publication: two economic professors … who have been measuring IQ. Sounds legit.