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Re:Leaded fuel reduced IQ of children born before 1990 by postalrat on Wednesday October 20, 2021 @10:45AM (#28931259)
We are still discovering what lowered the IQ of children born after 1990.
Re:Leaded fuel reduced IQ of children born before 1990 by johanneskanybal on Wednesday October 20, 2021 @12:13PM (#28932467)
You probably meant it as a joke (it was ok) but since half the comments are not:

"The change in IQ scores has been approximately three IQ points per decade. One major implications of this trend is that an average individual alive today would have an IQ of 130 by the standards of 1910, placing them higher than 98% of the population at that time."

https://ourworldindata.org/intelligence

Personally few things triggers me as older generations bashing younger, everything since ww2 has been easier the older you where and they where the ones raising that younger generation. Bit of typical not-getting-it.

Re:Leaded fuel reduced IQ of children born before 1990 by spangry on Wednesday October 20, 2021 @06:52PM (#28937872)
There's some evidence, at least in first-world countries, that more recently the Flynn effect is stagnating and even reversing (i.e. average IQs are declining). See: https://en.wikipedia.org/wiki/Flynn_effect#Possible_end_of_p...
Re:Leaded fuel reduced IQ of children born before 1990 by q1w2 on Wednesday October 20, 2021 @02:34PM (#28934316)
I wonder if this has anything to do with the correlative studies that showed that higher IQ individuals have less children on average.

https://en.wikipedia.org/wiki/Fertility_and_intelligence

Re:Leaded fuel reduced IQ of children born before 1990 by pedrosorio on Wednesday October 20, 2021 @03:26PM (#28935025)
higher IQ individuals having less children should lead to a decrease of average IQ, whereas the parent cites a reported 3 point increase per decade
Re:Leaded fuel reduced IQ of children born before 1990 by BatFastard on Wednesday October 20, 2021 @04:17PM (#28935854)
As much as IQ tests want to say they test raw intelligence, education plays a major role in how well you score. And we are better educated as a society than we were 100 years ago.
Re:Leaded fuel reduced IQ of children born before 1990 by jVinc on Wednesday October 20, 2021 @05:19PM (#28936795)
When looking at IQ increase over time, you control for education and socioeconomic factors, otherwise you're just drawing conclusions from those factors.
Re:Leaded fuel reduced IQ of children born before 1990 by philosopher1234 on Wednesday October 20, 2021 @07:31PM (#28938233)
How can you control for education when education itself has changed?
Re:Leaded fuel reduced IQ of children born before 1990 by beamatronic on Wednesday October 20, 2021 @01:00PM (#28933074)
If the world is the most peaceful it's ever been, and people are the smartest they've ever been, what does that mean for land and housing prices in a fiat economy?
Re:Leaded fuel reduced IQ of children born before 1990 by j_walter on Wednesday October 20, 2021 @10:57AM (#28931400)
Social media
Re:Leaded fuel reduced IQ of children born before 1990 by Tenoke on Wednesday October 20, 2021 @12:00PM (#28932322)
This is such a populist response but I doubt you have any citations backing that claim. Please post if you do.
Re:Leaded fuel reduced IQ of children born before 1990 by j_walter on Wednesday October 20, 2021 @12:28PM (#28932661)
https://neurogrow.com/what-social-media-does-to-your-brain/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6502424/

For instance, the Internet's digital distractions and supernormal capacities for cognitive offloading seem to create a non‐ideal environment for the refinement of higher cognitive functions in critical periods of children and adolescents’ brain development. Indeed, the first longitudinal studies on this topic have found that adverse attentional effects of digital multi‐tasking are particularly pronounced in early adolescence (even compared to older teens), and that higher frequency of Internet use over 3 years in children is linked with decreased verbal intelligence at follow‐up, along with impeded maturation of both grey and white matter regions.

Re:Leaded fuel reduced IQ of children born before 1990 by Tenoke on Wednesday October 20, 2021 @12:39PM (#28932799)
This paper doesn't mention IQ even once. It just discusses general effects it can have e.g. potential problems with multi-tasking for some, possible beneficial effects via increased mental stimulation for the elderly etc. This is quite different than what you initially proposed, not to mention inconclusive.
Re:Leaded fuel reduced IQ of children born before 1990 by j_walter on Wednesday October 20, 2021 @02:04PM (#28933840)
What do you think cognitive decline means? IQ tests are also called cognitive assessments and the accurate ones (not the ones you take online) involve a lot of different aspects of assessing how your brain is working. Many psychologists don't like the term IQ because it's too basic of a term...which is why many papers studying the subject do not include it.

http://pictonpsychology.com.au/home-2/assessments/cognitive-...

Re:Leaded fuel reduced IQ of children born before 1990 by uoaei on Wednesday October 20, 2021 @06:58PM (#28937926)
I don't think you are using the word "populist" correctly.
Re:Leaded fuel reduced IQ of children born before 1990 by anthk on Wednesday October 20, 2021 @11:02AM (#28931462)
Literally. Social media and multitasking reduces your IQ several points down.
Re:Leaded fuel reduced IQ of children born before 1990 by guruz on Wednesday October 20, 2021 @06:49PM (#28937838)
My bet is on seed oils :-/

https://www.reddit.com/r/StopEatingSeedOils/

(And also what others posted: plastic, social media etc.)

Re:Leaded fuel reduced IQ of children born before 1990 by creamyhorror on Thursday October 21, 2021 @08:46AM (#28943623)
Complicated topic. Canola and corn oil don't seem associated with increased mortality: (Zhang 2021) https://bmcmedicine.biomedcentral.com/articles/10.1186/s1291...

But we have small indications (Ramsden 2013, 2016) that too much linoleic acid (an omega-6 fat) could be detrimental. At the same time, canola and corn oil are rich in it and aren't correlated with higher risk of death in big observational studies.

Seed oils are probably not as bad as some fear, given that we don't see increased deaths associated with it in observational studies. But you might as well use olive oil (for more omega-3 fat) instead if you can afford it.

Re:Leaded fuel reduced IQ of children born before 1990 by purple_ferret on Wednesday October 20, 2021 @11:17AM (#28931698)
plastics and plastic byproducts
Re:Leaded fuel reduced IQ of children born before 1990 by jrootabega on Wednesday October 20, 2021 @01:38PM (#28933501)
Pity the generation whose elderly parents will have been raised on leaded gasoline and whose children will have been raised on smartphones.
Re:Leaded fuel reduced IQ of children born before 1990 by mfer on Wednesday October 20, 2021 @12:03PM (#28932361)
What is IQ? It's a measure that involves different categories. Some of those categories have seen decline for decades while others have seen an increase. Digging deeper can highlight more detail. Sadly, little of this is documented in easy to find places online.
Re:Leaded fuel reduced IQ of children born before 1990 by mschuster91 on Wednesday October 20, 2021 @11:25AM (#28931833)
If I were to guess, stress is responsible for a large part of it - stress is already known to have side effects in mental health and life expectancy. I mean... my generation (as someone born in 1991), what did we experience in our formative years? Nothing but a perpetual state of crisis:

- for Americans, the numerous wars in Afghanistan, Iraq and in other countries - not to mention 9/11 itself which hit right as many of my generation were in childhood and old enough to understand what is going on in the news

- the financial crisis 2008ff which will leave those who graduated around it with lifetime lower earnings (https://www.pymnts.com/economy/2020/millennials-facing-secon...)

- for the Europeans, the Euro crisis not soon after, same effect if not worse, given the devastation it caused in Southern Europe / PIIGS states

- for Europeans, dealing with the refugees that all the wars in Africa and Asia caused, culminating in the 2015ff migration crisis

- worldwide, anyone not completely ignorant already sees the catastrophic effects of climate change and the utter inaction of our politicians. We see that the world is figuratively speeding with 200 km/h against a rapidly upcoming brick wall, we see that instead of applying the brakes, the 1% of rich and elites instead maxes out the throttle, and we know that we are going to take the beginning of its effects in 30 years and our children face the full impact. Old people complain why the youngest are on strike on Fridays instead of going to school - well, they are aware that no amount of education can help them if the planet is nearing inhabitability!

- and on top of that, we have a new crisis looming in the form of Russia destabilizing Western governments by propaganda and cyberwars, and China taking parts right out of the NSDAP playbook and acting like a schoolyard bully in the Pacific region all the way to Australia.

- did I already mention that my and the later generations will face significantly less earnings than the generation of Boomers, and that income and wealth inequality also has risen constantly over the last decades?

- as a result, home ownership is ever more inachievable, in contrast to our parents we have to regularly be on the move and uproot ourselves (thus, losing our meatspace social network) every couple of years because the only way to achieve wage raises is to move companies

- and on top of all of what I mentioned, we have the aftermath of the Covid crisis that showed just how fundamentally broken our societies and economies are, how incompetent and reckless our politicians are, how utterly ignorant politics and society acted when it came to the needs of the young (we sacrificed our youth for the at-risk population, and got rewarded with anti-vaxxers and police smashing outdoor parties as a thank-you), that wrecked entire economies beyond belief and many of us lost people held dearly under sometimes egregious circumstances!

All of this is a permanent mental load, in some cases (especially when it comes to Covid) we are crossing into trauma territory. I'm seriously interested in the first psychological research dealing with stress influence of the last two decades.

Re:Leaded fuel reduced IQ of children born before 1990 by selimnairb on Wednesday October 20, 2021 @11:32AM (#28931947)
Be thankful you weren't a child during the Reagan years. When I was around 8 years-old, every time I saw jet contrails I was convinced they were incoming USSR ICBMs.
Re:Leaded fuel reduced IQ of children born before 1990 by java-man on Wednesday October 20, 2021 @12:12PM (#28932461)
Incoming ICBMs would look very different (something like bright meteors).

Edit: I know, through the eyes of an 8 year old. My city was a target of the U.S. nuclear missiles, so the I had the same fear. Saw nuclear exposions all the time in my dreams.

[0] https://www.youtube.com/watch?v=1WagAKBuc_o

[1] https://www.youtube.com/watch?v=j7X89a531CY

Re:Leaded fuel reduced IQ of children born before 1990 by burnafter182 on Wednesday October 20, 2021 @12:52PM (#28932973)
Hey old friend,

Do you think, that having been through Cold-war era conditioning and propaganda, that you're sort of sensitized to the "modern Russia tropes"? I ask because, well Russia seems like a shithole. A sort of noncompete on the global scale outside their natural resource stockpiles, but the US demagogues seem to like to point fingers there and I see it as more or less a propaganda tool. I suspect it's aimed at the generations that experienced the cold war, but I'm inducing hard.

Re:Leaded fuel reduced IQ of children born before 1990 by java-man on Wednesday October 20, 2021 @01:01PM (#28933085)
I think a lot of people miss the Cold War. There was this far away, monolythic, scary enemy, that can be reliably used to justify any amount of military expenses. And to a certain point it was, of course, since up until 1953 they were expecting a "world revolution".

The situation changed ever so slightly after 1985, culminating in dissolution of USSR. Good riddance!

And now the same forces - or new incarnation of the same forces - are working again to create that image of an absolute enemy - on both sides. It's just so easy.

Re:Leaded fuel reduced IQ of children born before 1990 by SideburnsOfDoom on Wednesday October 20, 2021 @12:16PM (#28932513)
Thanks, but I don't really think that's the point at all.

The parent commenter relates that they were 8 years old and not a missile identification expert at that age; but stressed about by something that actually was a realistic fear.

Re:Leaded fuel reduced IQ of children born before 1990 by Diederich on Wednesday October 20, 2021 @12:27PM (#28932643)
> 8 years-old
Re:Leaded fuel reduced IQ of children born before 1990 by tandr on Wednesday October 20, 2021 @12:20PM (#28932555)
Source?
Re:Leaded fuel reduced IQ of children born before 1990 by java-man on Wednesday October 20, 2021 @12:32PM (#28932710)
Re:Leaded fuel reduced IQ of children born before 1990 by tandr on Thursday October 28, 2021 @10:03AM (#29026253)
Thank you.
Re:Leaded fuel reduced IQ of children born before 1990 by tonyedgecombe on Wednesday October 20, 2021 @12:07PM (#28932411)
I was a teenager when Reagan came to power, the idea of a nuclear holocaust was in our faces thanks to stuff like this:

https://www.youtube.com/watch?v=F0OPVi90-lg

Re:Leaded fuel reduced IQ of children born before 1990 by gremIin on Wednesday October 20, 2021 @02:36PM (#28934339)
Except that was a hypothetical. The effects of climate change are real, and irreversible.
Re:Leaded fuel reduced IQ of children born before 1990 by q1w2 on Wednesday October 20, 2021 @02:28PM (#28934204)
As a child in the Reagan years, this was not a source of stress for myself or any kid I knew.
Re:Leaded fuel reduced IQ of children born before 1990 by brewdad on Wednesday October 20, 2021 @03:28PM (#28935049)
We were still doing nuclear attack drills in my elementary school during the Reagan years, so yeah.
Re:Leaded fuel reduced IQ of children born before 1990 by scruple on Wednesday October 20, 2021 @06:24PM (#28937608)
Same here. To make matters worse, I used to confuse the tornado sirens in our town for air raid / civil defense sirens when I was very young and I remember being quite afraid of them, even when I knew they were routine tests, until I finally understood the difference.
Re:Leaded fuel reduced IQ of children born before 1990 by indymike on Wednesday October 20, 2021 @12:39PM (#28932798)
I wonder if one big stressor is better than a thousand small stressors.
Re:Leaded fuel reduced IQ of children born before 1990 by dionidium on Wednesday October 20, 2021 @04:31PM (#28936070)
This is extreme myopia. You could make a list like this for any given 40-year period and in the earlier periods disease would be worse, healthcare would be worse, material living standards would be worse, and life expectancy would be lower.

I think it's basically laughable to suggest that millennials have experienced more stress than earlier generations. (Not that it matters, but I'm an older millennial myself.)

Now, it genuinely might be the case that millennials are subjectively more "stressed out" than their predecessors, but that's a different claim. It's a claim I don't have any trouble believing, but the cause is likely widespread access and attention to negative stressors (via social media, for example), not the existence of a greater number of them.

Re:Leaded fuel reduced IQ of children born before 1990 by spfzero on Wednesday October 20, 2021 @01:04PM (#28933109)
"they are aware that no amount of education can help them if the planet is nearing inhabitability"

Do you really believe that? That Earth will be uninhabitable within the lifetime of a person alive today? Or their grandchildren? No climate scientists argue anything remotely close to that outcome.

Re:Leaded fuel reduced IQ of children born before 1990 by burnafter182 on Wednesday October 20, 2021 @02:24PM (#28934128)
Well, that depends on the human reaction. Think of screaming "fire" in a movie theatre. Panicked rush out, egregious disregard for human life and safety for the sake of self-preservation. Consider our theatre patrons are armed, guns, knives, nuclear weapons, economic warfare. I'm not saying there is necessarily going to be world destruction, but it isn't-not on the menu.
Re:Leaded fuel reduced IQ of children born before 1990 by mschuster91 on Wednesday October 20, 2021 @01:28PM (#28933387)
> That Earth will be uninhabitable within the lifetime of a person alive today?

For people in Africa threatened by heat and drought (which is already making places uninhabitable and causing migration!) and smaller islands, yes.

Re:Leaded fuel reduced IQ of children born before 1990 by burnafter182 on Wednesday October 20, 2021 @02:36PM (#28934347)
How many climate predictions have been correct? How many predictions in general have, a posteriori been right? This is multivariate, not necessarily a question of the effects of climate itself, but every conceivable effect in a long chain, including further human intervention and non-linearities in global climate behavior that are yet-to-be observed and no doubt a lengthy slew of other factors. But we're not allowed to talk about speculation, right?
Re:Leaded fuel reduced IQ of children born before 1990 by q1w2 on Wednesday October 20, 2021 @02:31PM (#28934248)
This is simply not accurate. There might be certain areas that are more impacted than others, like the Maldives, but there is no reasonable interpretation of "uninhabitable" any scientist would attribute to Africa, let alone Earth entirely.
Re:Leaded fuel reduced IQ of children born before 1990 by spfzero on Wednesday October 20, 2021 @04:48PM (#28936330)
"places" uninhabitable is not the same as the planet being uninhabitable, as the parent post claimed. Parts of the planet have been uninhabitable for ages.
Re:Leaded fuel reduced IQ of children born before 1990 by syshum on Wednesday October 20, 2021 @12:03PM (#28932370)
My mentality seems to be very different from the norm, because none of those things cause me any stress at all.

I think about them from a Policy stand point, I may recycle or by a sustainable product because I know about climate change, but I am not stressed over climate change

I am not stressed over wars in Afghanistan or Iraq, I oppose them from a policy stand point, I am sad and empathetic for the lives lost needlessly.

Even COVID, did not cause me any stress. I looked at the data, I isolated myself when appropriate, wore a mask when appropriate, and got vaccinated when appropriate I did not have an existential crisis of the mind where I was in fear that I was going to die, not at any point in the pandemic. Certainly not to the point where I have seen others be; out on the street screaming @ people that did not conform to societal or government demands or claiming those people are a "threat" to my life.

So I honestly have no frame of reference for people that have this "permanent mental load" where all of these things cause them soo much stress that is impacts their life.

Re:Leaded fuel reduced IQ of children born before 1990 by tonyedgecombe on Wednesday October 20, 2021 @12:12PM (#28932457)
I've noticed my conservative friends have tended to be much more fearful of this stuff. This was especially noticeable during 9/11.
Re:Leaded fuel reduced IQ of children born before 1990 by syshum on Wednesday October 20, 2021 @12:27PM (#28932645)
I dont think is a conservative / liberal thing.

Yes some conservatives have a greater reaction to 9/11, and seem to be more suspectable to external threats / rhetoric like Islamic terrorism, china, russia, etc.

However when it comes to things like the pandemic, or internal threats like domestic terrorism, or "Trump" like presidents, etc liberals seems to become just as unhinged and stressed as the most extreme conservative does over an Islamic Terror event...

If you are not seeing that likely because you are more closely aligned with one group over the other.

I am close to neither, as I am more an individualist and reject any type of collectivism from religion, to government structures, to golf clubs, if it is a group I want no part of it

Re:Leaded fuel reduced IQ of children born before 1990 by tonyedgecombe on Wednesday October 20, 2021 @03:08PM (#28934792)
>I dont think is a conservative / liberal thing.

>Yes some conservatives have a greater reaction to 9/11, and seem to be more suspectable to external threats / rhetoric like Islamic terrorism, china, russia, etc.

So which is it? :)

>If you are not seeing that likely because you are more closely aligned with one group over the other.

Well I'm in the UK which is a completely different world when it comes to politics. Even then I don't really identify with either of the main parties, I could pick issues that I align with from both sides.

>If you are not seeing that likely because you are more closely aligned with one group over the other.

Yet you reacted when I mentioned conservatives.

>I am close to neither, as I am more an individualist and reject any type of collectivism from religion, to government structures

That sounds fairly conservative to me.

Re:Leaded fuel reduced IQ of children born before 1990 by syshum on Wednesday October 20, 2021 @03:25PM (#28935015)
>>So which is it? :)

Again it is applicable to both, you asserted it was only conservatives that have this trait, I contend it is both.

>>Well I'm in the UK

I am sorry ;)

>>Yet you reacted when I mentioned conservatives.

No I continued the dialog we are having by responding to your assertion and disagreeing where I felt your argumentation was flawed

>>That sounds fairly conservative to me.

Depends on how you define your politics, if you do so on a single axis Left/Right. Liberal / Conservative. Maybe.

I tend to look at politics more like the Political Compass[1] for which I am dead center between left and right, but I am extremely far down on the libertarian scale

[1]https://en.wikipedia.org/wiki/The_Political_Compass

Re:Leaded fuel reduced IQ of children born before 1990 by VirusNewbie on Wednesday October 20, 2021 @12:34PM (#28932742)
My parents both grew up in poverty in disparate communities and both experienced potential food shortages.

Later in his early twenties my father was drafted. They also spent time doing bomb drills in elementary school because of the cold war, nuclear fallout was an actual worry.

>did I already mention that my and the later generations will face significantly less earnings than the generation of Boomers, and that income and wealth inequality also has risen constantly over the last decades?

I do worry about rising wealth inequality, but that is largely a factor of deficit spending and needing the fed to print money causing wealth transfer to the upper class. Unfortunately, most young people are all for the government spending even more money for various things which will only exacerbate the issue.

>(we sacrificed our youth for the at-risk population),

I dunno, the largest cohort of covid positive cases has always been the 20-30 age group by far.

Re:Leaded fuel reduced IQ of children born before 1990 by cudgy on Wednesday October 20, 2021 @04:32PM (#28936092)
“Unfortunately, most young people are all for the government spending even more money for various things which will only exacerbate the issue.”

The issue is not the amount of money that is spent; the issue is for what the money is spent. So many articles discussing the current bills in Congress simply stating the amounts of money that are allocated in aggregate with little if any discussion of the specific amounts within the bill. My skeptical mind thinks this is purposely done to mislead the public.

Re:Leaded fuel reduced IQ of children born before 1990 by rufus_foreman on Wednesday October 20, 2021 @07:48PM (#28938393)
>> for Americans, the numerous wars in

Only the dead have seen the end of war. As far as stress on a populace goes, anyone my age (50) or younger has had it pretty easy. My parents' generation had to deal with the possibility of getting drafted to fight in Vietnam. My grandparents' generation had to deal with the much higher possibility that they were going to have to fight in World War II. A 20 year old trying to get some sleep because in the morning he is going to have to storm the beaches of Normandy, that's some stress. What my generation dealt with, stressful sure, but not as much.

>> the financial crisis

There's always going to be another financial crisis. My grandparents grew up during the Great Depression. The 70s had stagflation. I first learned how to freak out about the stock market in the late 90s. There was the 2008 financial crisis, and after that there was the longest economic expansion in US history. Do people just wipe that part out of their memories? Out of all of it, I would pick anything but the Great Depression.

>> anyone not completely ignorant already sees the catastrophic effects of climate change

When I was young, it was overpopulation, then a coming ice age, then ozone and acid rain, then global warming. If you look at what the scientists are actually predicting, it is that we will be much better off at the end of the century but not as much better off as if we had taken more action now.

>> we have a new crisis looming in the form of Russia destabilizing Western governments by propaganda and cyberwars

When I was a young teen, I seriously believed I would die in a nuclear war before I was 18. Now people are freaking out about Russia trolling people on the internet.

>> did I already mention that my and the later generations will face significantly less earnings than the generation of Boomers

Boomers started in what, 1946? In 1950, one third of the households in the US didn't have indoor plumbing. And you're jealous of them.

>> home ownership is ever more inachievable

The home ownership rate is lower than it was in 2000, higher than it was in 1990, around the same as it was in 1980, and higher than it was in 1970. Rental affordability is a little lower than in the past, mortgage affordability much higher (due to low interest rates). People change jobs less than they used to and they move less than they used to. Not really seeing peak stress here.

Sure, Covid was stressful for some people. Not for me, it's been the least stressful year and a half of my life. I don't see the whole fundamentally broken part. If you had told me that there was going to be a global pandemic that pretty much shut down the US economy for a time, I would have thought it would have turned out worse than it did.

[dead]
Re:Leaded fuel reduced IQ of children born before 1990 by anyfoo on Wednesday October 20, 2021 @03:26PM (#28935017)
You get downvoted, and I understand why (HN does not like most jokes and for good reasons and so on), but I think that was actually a very appropriate reaction. Anyone having spent time on Facebook knows exactly what, and in what way, you meant that.
Re:Leaded fuel reduced IQ of children born before 1990 by paulpauper on Wednesday October 20, 2021 @11:20AM (#28931758)
if everything is lowering IQs at all time, wouldn't it just be reflected in the mean then? This would imply that IQ tests would have to get easier over time to keep the average at 100.
Re:Leaded fuel reduced IQ of children born before 1990 by Imnimo on Wednesday October 20, 2021 @11:35AM (#28931978)
https://en.wikipedia.org/wiki/Flynn_effect (tests are re-standardized to keep the mean at 100, but the un-standardized mean actually increases over time)
Re:Leaded fuel reduced IQ of children born before 1990 by paulpauper on Wednesday October 20, 2021 @11:52AM (#28932204)
then doesn't this counter the argument that IQs are falling
Re:Leaded fuel reduced IQ of children born before 1990 by Tenoke on Wednesday October 20, 2021 @11:57AM (#28932269)
It does. They are not. Or at least if some factors are lowering it, other factors like better nutrition and deleading etc. are more than counteracting it.
Re:Leaded fuel reduced IQ of children born before 1990 by steerablesafe on Wednesday October 20, 2021 @01:48PM (#28933639)
Re:Leaded fuel reduced IQ of children born before 1990 by mschuster91 on Wednesday October 20, 2021 @11:29AM (#28931913)
You would still have outliers that raise the mean - mostly children from wealthy people who can afford to raise their children on rural-ish areas, away from environmental pollution (not just lead, but also particulate matter dust/NOx from roads, industrial airborne toxins, and noise).
Re:Leaded fuel reduced IQ of children born before 1990 by handrous on Wednesday October 20, 2021 @12:32PM (#28932717)
There aren't enough people so rich that they can live in country estates and remote coastal "summer" residences all year (so, neither parent has a job they need to be at) while sending their kids to rural boarding schools to show up in those stats, I expect. Plus you may have trouble pinning down where they actually live most of the time, even if you tried to account for them.

Beyond that, given rural areas have been subject to over a century of severe brain-drain and intelligence is fairly heritable, I'd expect that to overwhelm any benefits of country living, if you tried to measure the effect for a general rural population. You'd need a twin study or something like that to sort it all out, i.e. a bunch of twins where one grew up in the country, one in the city or 'burbs or whatever you're comparing it to.

Re:Leaded fuel reduced IQ of children born before 1990 by Tenoke on Wednesday October 20, 2021 @11:58AM (#28932296)
If people in rural area have higher IQs (which I doubt) you'd expect to see a decrease as there's way less people living ruraly today than before.
Re:Leaded fuel reduced IQ of children born before 1990 by mitigating on Wednesday October 20, 2021 @12:45PM (#28932878)
Sometimes it's not how smart you are but if you can utilize that. Many people can't afford higher education, especially from rural areas, there's also stereotypes based on accents and mannerisms that could prevent growth at a company. People in rural areas are also farther away from large companies and may be unable/unwilling to move.