Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Lead exposure in last century shrunk IQ scores of half of Americans: study

today.duke.edu

Post reply on HN
Print view View original

131–140 of 508 posts

Re: Lead exposure in last century shrunk IQ scores of half of Americans: study

#131

Post by tomxor »

lhoff wrote: post #93
alyandon wrote: post #63

Earlier quoted context omitted.

Indeed. Added sugar and high fructose corn syrup is in everything. I have to go out of my way to find a brand of bread that doesn't have added high fructose corn syrup. It's ridiculous.

I havent bought bread in probably 4 Years now. Investing half an hour of work (distributed over the day) every other week for a 2kg Bread. Half of it goes in the freezer. Also buying fresh vegtables and cooking instead of buying ready made dishes helps.

Yup, this is basically the only realistic way to avoid it, switch to types of food that cannot by their very nature have sugar added.

Re: Lead exposure in last century shrunk IQ scores of half of Americans: study

#132

Post by somenameforme »

JaimeThompson wrote: post #87
legitster wrote: post #61

I have a strong worries that our current generation will have a similar huge reckoning with marijuana. We are already seeing studies that show regular marijuana use is correlated with permanent decreases in intelligence, memory loss, motivation, and mental health. And anecdotally, this seems very apparent in my peer group. And Americans are using copious amounts of the stuff right now, and younger than ever before. I…

Perhaps if the typical American was paid better and had more hope for the future then less would use such things to escape from reality.

When saying things like this, I think you should intuitively consider the corollary of your sentence. If people are using drugs to "escape from reality" presumably because have insufficient money to do nicer things, then the implication is that people who have lots of money would use drugs at a substantially lower rate.

And so this is pretty easy to test. I did a quick search for 'marijuana use by rate by income' and the first paper that I came upon [1] showed there is indeed quite a strong correlation between substance use and socioeconomic status - in other words, the richer or more privileged individuals were (in terms of coming from wealthy family backgrounds), the more likely they were to use drugs.

So unless there is some confounding variable that we may not be considering, it seems fairly easy to reject the hypothesis that people are using drugs because of a lack of money.

[1] - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3410945/

Re: Lead exposure in last century shrunk IQ scores of half of Americans: study

#133

Post by [deleted] »

axiosgunnar wrote: post #117
legitster wrote: post #61

I have a strong worries that our current generation will have a similar huge reckoning with marijuana. We are already seeing studies that show regular marijuana use is correlated with permanent decreases in intelligence, memory loss, motivation, and mental health. And anecdotally, this seems very apparent in my peer group. And Americans are using copious amounts of the stuff right now, and younger than ever before. I…

Interesting. What about porn abuse?

[deleted]

Re: Lead exposure in last century shrunk IQ scores of half of Americans: study

#134

Post by scythe »

paulpauper wrote: post #85
veltas wrote: post #6

Didn't we have a previous study debunking this research on statistical grounds?

a meta study showed the effect to be minimal to zero https://greyenlightenment.com/2021/08/02/the-effects-of-lead...

That's focused on crime, not IQ/cognition. Crime is not a purely mental phenomenon, so it would likely have a weaker correlation with lead even if the effect is real. The blog post does try to dissemble on the IQ question, but the only evidence presented shows a significant effect of lead (contra the blogger's thesis).

Re: Lead exposure in last century shrunk IQ scores of half of Americans: study

#135

Post by austinjp »

bsedlm wrote: post #17
veltas wrote: post #6

Didn't we have a previous study debunking this research on statistical grounds?

there's this thing about the modern internet era which makes it possible to find a study to debunk (or support) pretty much any idea/theory you want. specially in the midst of an information/propaganda war all I'm trying to say is that I have decided not to think in the way you just did e.g. "where's that study which supports what I already believe?". It doesn't seem like a good tactic anymore

Indeed. One issue we have today is a glut of scientific information, some of which is high quality and some isn't. Also, some will later be shown to be false, and some correct, in any given context.

It's not enough to say simply that a study exists (even if it is a large meta-study); it's necessary to actually read it in full and critically appraise it.

But ain't nobody got time for that.... which is a problem!

Re: Lead exposure in last century shrunk IQ scores of half of Americans: study

#136

Post by legitster »

Tenoke wrote: post #89
legitster wrote: post #61

I have a strong worries that our current generation will have a similar huge reckoning with marijuana. We are already seeing studies that show regular marijuana use is correlated with permanent decreases in intelligence, memory loss, motivation, and mental health. And anecdotally, this seems very apparent in my peer group. And Americans are using copious amounts of the stuff right now, and younger than ever before. I…

>We are already seeing studies that show regular marijuana use is correlated with permanent decreases in intelligence, memory loss, motivation, and mental health. I can maybe believe it but I am yet to see a convincing Meta-Analysis or at least a large RCT. In general, people seem to recover from a lot of drug usage if they stop for long enough and weed isn't one of the heavy ones. Can you share what studies you are…

The study in the linked article found that lead reduced the IQ of exposed Americans 3-6 IQ points.

A New Zealand study found that persistent cannabis users had a 6-8 point decline, even if they had given up cannabis: https://www.pnas.org/doi/abs/10.1073/pnas.1206820109

Here's a meta review that found a 2 IQ point drop across a wider range of usage types: https://www.cambridge.org/core/journals/psychological-medici...

There's a lot less known about cannabis at this point, but what we know so far isn't very positive.

Re: Lead exposure in last century shrunk IQ scores of half of Americans: study

#137

Post by bdamm »

nynx wrote: post #31
miketery wrote: post #20

Earlier quoted context omitted.

Same goes for sugar. We know the dangers it poses, we are also seeing how much it increases risk of death due to covid. I don't think we should be surpsied, as much as pushing to regulate this garbage. As an aside, Michelle Obama's campaign when Obama was in office was about improvement children's health. Her focus was going to be on nutrition (lunch food). Shortly thereafter Coke and Pepsi came in with "donations" a…

Sugar is at least a substance that one can choose not to eat. Lead poisoning and pollution aren’t choices.

Between the marketing for children, the many "sugar holidays" (Valentines, Easter, Christmas, Halloween, etc), the widespread use of processed foods in children's diets, the fact that every single grocery store in America puts sugar products on loud display, and that some restaurants only serve sugar based drinks, I would argue that it is not possible for American children to avoid sugar.

Re: Lead exposure in last century shrunk IQ scores of half of Americans: study

#138

Post by ryan93 »

micromacrofoot wrote: post #73
xhkkffbf wrote: post #49

Earlier quoted context omitted.

But then there's been a huge rise in crime. The murder rate in some cities is dramatically higher than just a few years ago. But it's not like the gas suddenly became leaded again. This makes me think that we just can't be too certain about these things.

> But then there's been a huge rise in crime Is this actually true? I've seen a lot of people saying this politically but haven't seen a lot of data to back it up. From what I've seen there's been a slight bump, which isn't too surprising given the state of everything... but it's still massively dwarfed by the decrease in the 90s and 00s For example https://www.bbc.com/news/57581270

https://www.pewresearch.org/fact-tank/2021/10/27/what-we-kno...

Re: Lead exposure in last century shrunk IQ scores of half of Americans: study

#139

Post by blaser-waffle »

rootusrootus wrote: post #30
banana_maker wrote: post #21

Earlier quoted context omitted.

As of 2021, out of 432 members in the house of congress, a scant 31 are millenials. In the senate, just 1. Millenials are -not- the ones responsible for disastrous policies (yet). They haven't been around long enough yet. It's mainly boomers, some gen x, and a few silents. https://www.pewresearch.org/fact-tank/2021/02/12/boomers-sil... edit: Added "(yet)" because it's not obvious, I suppose. My point here is that the…

Who is the largest single voting bloc? Edit: That struck a chord with millenials, ha! Tell your friends that bitching does not help, voting does. Boomers seem to understand this and so they have a disproportionate amount of influence. You want it to stop? VOTE.

> Edit: That struck a chord with millenials, ha! Tell your friends that bitching does not help, voting does. Boomers seem to understand this and so they have a disproportionate amount of influence. You want it to stop? VOTE.

There is, still, a statistical bump in the boomers, hence the baby boom.

There is just more of them, and they vote. They've only just started dying in big numbers.

Plus the older voters get the more they tend to vote, for various reasons.

Re: Lead exposure in last century shrunk IQ scores of half of Americans: study

#140

Post by legitster »

woodruffw wrote: post #100
legitster wrote: post #61

I have a strong worries that our current generation will have a similar huge reckoning with marijuana. We are already seeing studies that show regular marijuana use is correlated with permanent decreases in intelligence, memory loss, motivation, and mental health. And anecdotally, this seems very apparent in my peer group. And Americans are using copious amounts of the stuff right now, and younger than ever before. I…

I agree with some of this in the abstract, but I think it's worth noting that "regular use" in academic studies of marijuana usually entails dosing lab animals with quantities that a human being couldn't physically consume, or surveying the (much smaller) population of people with psychological addictions to marijuana. OTOH, and this is anecdotal, I worry about how potent a lot of "normal" marijuana has become and ho…

But we still do have studies that compare cannabis users to non-users.

The concern for marijuana is less about the toxicity of it as a substance, and more the psychological effects of being high.

Post reply on HN