Has the lead-crime hypothesis been debunked?(jabberwocking.com)
jabberwocking.com
Has the lead-crime hypothesis been debunked?
https://jabberwocking.com/has-the-lead-crime-hypothesis-been-debunked/
185 comments
Yeah me too, I was thinking crimes that precede other crimes. After seeing "Does lead pollution increase crime?" in the linked paper it all became clear. These articles should always, at least briefly, describe the subject that the meta is about.
I on the other hand assumed it was about initial/smaller crime "leading" into bigger/continues crimes.
I heart English Language!
I heart English Language!
So, the evidence for this hypothesis is extremely strong. There have been studies of children who did or did not get treated for high blood lead levels, and those who did not had much higher rates of criminal behavior. These were children from the same schools, same neighborhoods, same time. All the confounding circumstances are controlled.
The Lead-Crime Hypothesis may also refer to the idea that lead is the main reason for the global crime wave that peaked in 1990. The evidence for this is less convincing.
The Lead-Crime Hypothesis may also refer to the idea that lead is the main reason for the global crime wave that peaked in 1990. The evidence for this is less convincing.
> All the confounding circumstances are controlled.
How can you control everything? These studies do not control what no one thought about that it could have an effect. Its impossible to control everything.
How can you control everything? These studies do not control what no one thought about that it could have an effect. Its impossible to control everything.
It's as close as you'll get to a random controlled experiment on this topic, because an actual controlled experiment would not be ethical. Studying people from the same school who lived in the same neighborhood at the same time controls a hell of a lot of the usual confounders.
True. Perhaps one possible confounder though is that parents who are attentive enough to think about lead paint and test for it / paint over it / remove it are also more clued in on other matters.
One of the studies I'm thinking of relies on the boundary effect, where children who tested with 100µg/dl of lead in their blood were all treated and those with 99.99µg/dl were not, and this threshold (I'm not sure exactly what it was) is way too high.
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Right. The same issue confounds studies that show charter schools perform better than their public school counterparts, after controlling for student demographics. It could be that the quality of a charter school education is truly better, but it’s also possible that parents who care enough about their kids’ education to take initiative to send them to a charter school provide a better home environment in general.
The strong evidences you are talking about are usually confounded by socioeconomic status. One recent longitudinal study in New Zealand have found only a very weak correlation:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5801257/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5801257/
That study isn't as powerful as what I mentioned. That is a longitudinal study of children who were exposed to lead, and their life outcomes. The study I want to mention was of children, all of whom were exposed to lead, but only some of whom were treated for it, based on a threshold of blood lead concentration. Figure 4 in this paper is particularly compelling. They show a strong correlation between blood lead levels and violent criminal behavior in later life, but the intervention group, who were exposed to lead but received treatments for it, had much lower rates of crime.
You should read it to see if you think they didn't control for socioeconomic factors well enough. Section II and Table 1 in particular. https://pubs.aeaweb.org/doi/pdfplus/10.1257/app.20160056
You should read it to see if you think they didn't control for socioeconomic factors well enough. Section II and Table 1 in particular. https://pubs.aeaweb.org/doi/pdfplus/10.1257/app.20160056
If one were receiving treatment for lead, wouldn’t that correlate with socioeconomic status? I’m sure many poor people went untreated and poverty leads to violent crime. Which page addresses this? I’m too lay to understand.
No, the treatments were all paid for by the government of North Carolina in this case, and were based on levels of lead concentration in the blood, not socioeconomic status. So by comparing those with slightly above the threshold (who got treatment and thus ended up with significantly lower lead levels in their blood) and those with slightly below the threshold (who did not receive treatment and therefore ended up with higher levels of lead in their blood) you can make an estimate of the effect of lead in the blood that should cut across SES. (This is described on page 316 of the pdf- actually page 2- if you tested above the 10 microgram/deciliter concentration twice you got treatment, if you tested above only once you did not get treatment. They did a matched control group where the initial tests matched a test in the treatment group and generally matched the SES and geography, but the second test was in the 5-10 mcg/dcl range. Thus there is strong evidence that the control kid had a blood-lead problem but just missed the cut-off for government treatment.)
Whenever a treatment is given based on a strict income threshold you have a nice natural experiment. Those who have income <= T receive treatment. Those who are > T (even one dollar above) do not. Therefore, those who are "near" T are a great cohort to study effects of the treatment, since their socioeconomic factors are so close.
It sounds like the parent comment was saying exactly this occurred for children exposed to lead, and those in the treatment group went on to have better outcomes.
EDIT: Looking through the abstract, it appears the threshold was on blood / lead concentrations. This means those who differed only a tiny amount in lead concentrations received different treatments (some vs none), and had different outcomes despite being similar in all other metrics. Figure 4 was pretty interesting.
It sounds like the parent comment was saying exactly this occurred for children exposed to lead, and those in the treatment group went on to have better outcomes.
EDIT: Looking through the abstract, it appears the threshold was on blood / lead concentrations. This means those who differed only a tiny amount in lead concentrations received different treatments (some vs none), and had different outcomes despite being similar in all other metrics. Figure 4 was pretty interesting.
The treatments in question are administered by the state, at no charge, and some of them are mandatory.
It's really not a long paper. Go read it.
It's really not a long paper. Go read it.
In the U.S., yes. In the rest of the developed world, no.
Impoverished children and expecting mothers have access to medicine paid by the government/taxpayer in the US through Medicaid
I know it's fun to posture about how backwards the US healthcare system is but we actually do literally have the system in place that you're virtue signaling about us not having, as it applies to children
People act like the US has no welfare at all and it just isn't true. Children whose parents can't afford treatment can still get treatment, and have been able to for more than half a century.
My own niece was born in a hospital because of this. My adult sister received treatment for her collapsed lung at the same time, paid for by the taxpayer, because she couldn't afford it.
Medicare and Medicaid might not be perfect but acting like the US has no safety net is a lie
I know it's fun to posture about how backwards the US healthcare system is but we actually do literally have the system in place that you're virtue signaling about us not having, as it applies to children
People act like the US has no welfare at all and it just isn't true. Children whose parents can't afford treatment can still get treatment, and have been able to for more than half a century.
My own niece was born in a hospital because of this. My adult sister received treatment for her collapsed lung at the same time, paid for by the taxpayer, because she couldn't afford it.
Medicare and Medicaid might not be perfect but acting like the US has no safety net is a lie
In an shorthand comment, I’m not sure if we can differentiate if the commenter was saying there is literally no safety net, or if the safety net is insufficient, and arguably unevenly applied based on region and race. One anecdote of someone reviving a medical service is certainly not sufficient for a discussion of the latter.
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Some previous lead-crime threads:
An Updated Lead-Crime Roundup (2018) - https://news.ycombinator.com/item?id=20101446 - June 2019 (11 comments)
New Evidence That Lead Exposure Increases Crime (2017) - https://news.ycombinator.com/item?id=17888291 - Aug 2018 (147 comments)
Lead: America's Real Criminal Element (2013) - https://news.ycombinator.com/item?id=17350912 - June 2018 (141 comments)
A Basic Cohort Test of the Lead-Crime Hypothesis - https://news.ycombinator.com/item?id=16349365 - Feb 2018 (45 comments)
New Zealand Study Provides More Support for Lead-Crime Hypothesis - https://news.ycombinator.com/item?id=16023218 - Dec 2017 (36 comments)
A Study That Bolsters the Lead-Crime Hypothesis - https://news.ycombinator.com/item?id=14488520 - June 2017 (121 comments)
Lead Water Pipes in 1900 Caused Higher Crime Rates in 1920? - https://news.ycombinator.com/item?id=11625158 - May 2016 (67 comments)
Lead and Crime: Another Look - https://news.ycombinator.com/item?id=10868980 - Jan 2016 (11 comments)
Did removing lead from petrol spark a decline in crime? - https://news.ycombinator.com/item?id=7618871 - April 2014 (270 comments)
Leaded gasoline caused violent crime? Critiques wanted. - https://news.ycombinator.com/item?id=5017804 - Jan 2013 (1 comment)
America's Real Criminal Element: Lead - https://news.ycombinator.com/item?id=5002806 - Jan 2013 (4 comments)
The Crime of Lead Exposure - https://news.ycombinator.com/item?id=2609158 - June 2011 (3 comments)
Has use of lead-free gas decreased the crime rate? - https://news.ycombinator.com/item?id=71878 - Oct 2007 (4 comments)
An Updated Lead-Crime Roundup (2018) - https://news.ycombinator.com/item?id=20101446 - June 2019 (11 comments)
New Evidence That Lead Exposure Increases Crime (2017) - https://news.ycombinator.com/item?id=17888291 - Aug 2018 (147 comments)
Lead: America's Real Criminal Element (2013) - https://news.ycombinator.com/item?id=17350912 - June 2018 (141 comments)
A Basic Cohort Test of the Lead-Crime Hypothesis - https://news.ycombinator.com/item?id=16349365 - Feb 2018 (45 comments)
New Zealand Study Provides More Support for Lead-Crime Hypothesis - https://news.ycombinator.com/item?id=16023218 - Dec 2017 (36 comments)
A Study That Bolsters the Lead-Crime Hypothesis - https://news.ycombinator.com/item?id=14488520 - June 2017 (121 comments)
Lead Water Pipes in 1900 Caused Higher Crime Rates in 1920? - https://news.ycombinator.com/item?id=11625158 - May 2016 (67 comments)
Lead and Crime: Another Look - https://news.ycombinator.com/item?id=10868980 - Jan 2016 (11 comments)
Did removing lead from petrol spark a decline in crime? - https://news.ycombinator.com/item?id=7618871 - April 2014 (270 comments)
Leaded gasoline caused violent crime? Critiques wanted. - https://news.ycombinator.com/item?id=5017804 - Jan 2013 (1 comment)
America's Real Criminal Element: Lead - https://news.ycombinator.com/item?id=5002806 - Jan 2013 (4 comments)
The Crime of Lead Exposure - https://news.ycombinator.com/item?id=2609158 - June 2011 (3 comments)
Has use of lead-free gas decreased the crime rate? - https://news.ycombinator.com/item?id=71878 - Oct 2007 (4 comments)
The lead-crime hypothesis is almost certainly true but the mass media reaction to it just shows how much is wrong with our society.
First of all, the lead-crime hypothesis is good news. It is great to realize that small entirely achievable environmental changes can cause such marked improvement in wellbeing in people's lives.
But for some reason it has not been accepted as good news by the mass media. And then you have papers like the one discussed by the article that try to debunk the theory on absolutely ridiculous grounds. (You see there are no studies disproving this theory therefore there must be studies disproving this theory, therefore this theory is wrong. What a bunch of BS!)
So why is the lead crime hypothesis treated so negatively by our elites? Perhaps to avoid another round of massive litigation. Perhaps to prevent people from finding other ways other pollution can affect people's behavior and thus prevent the banning of other substances and other rounds of massive litigation. Or perhaps to preserve an image key in international culture -- the violent city youth.
First of all, the lead-crime hypothesis is good news. It is great to realize that small entirely achievable environmental changes can cause such marked improvement in wellbeing in people's lives.
But for some reason it has not been accepted as good news by the mass media. And then you have papers like the one discussed by the article that try to debunk the theory on absolutely ridiculous grounds. (You see there are no studies disproving this theory therefore there must be studies disproving this theory, therefore this theory is wrong. What a bunch of BS!)
So why is the lead crime hypothesis treated so negatively by our elites? Perhaps to avoid another round of massive litigation. Perhaps to prevent people from finding other ways other pollution can affect people's behavior and thus prevent the banning of other substances and other rounds of massive litigation. Or perhaps to preserve an image key in international culture -- the violent city youth.
>So why is the lead crime hypothesis treated so negatively by our elites?
It's not just treated negatively by elites, but I think that's very straightforward. Because a biological or chemical explanation for behaviour, especially such a simple one, throws a pretty big wrench into the moralistic and individualistic worldview that underpins our Western societies, in particular in regards to crime or intellect.
If you accept the, from a scientific point, very obvious observation that a bunch of chemicals in your drinking water can turn you into an idiot or a criminal you just about undermine most stories of self-earned merit or responsibility we are being fed in our mother's milk and that justify bringing the hammer down on said inner city youth.
It's not just treated negatively by elites, but I think that's very straightforward. Because a biological or chemical explanation for behaviour, especially such a simple one, throws a pretty big wrench into the moralistic and individualistic worldview that underpins our Western societies, in particular in regards to crime or intellect.
If you accept the, from a scientific point, very obvious observation that a bunch of chemicals in your drinking water can turn you into an idiot or a criminal you just about undermine most stories of self-earned merit or responsibility we are being fed in our mother's milk and that justify bringing the hammer down on said inner city youth.
Yes. Everybody wants to believe in strong free will. Everybody. If you accept that one group isn’t entirely culpable for their actions than other groups will get the same treatment (kkk, date rapists, capitol protestors, etc…) Until we can accept that all humans are mostly products of genetics and environment, the push for legal reform will come down to political questions about which sorts of people we affiliate with the most.
I guess alcohol is a non-issue, then? Or are you restricting yourself only to some chemicals?
Alcohol is absolutely an issue, all drug use is. I don't limit myself to 'some' chemicals. But I'm not sure exactly what you're asking, are you asking if I think drug use ought to be treated the same way, as an environmental and behavioral issue, rather than some individualistic moral guilt thing? Yes, absolutely.
It's a good example actually. We've done incredible damage by moralizing drug use rather than treating it as medical issue and instead promote quackery like AA which has horrible outcomes.
It's a good example actually. We've done incredible damage by moralizing drug use rather than treating it as medical issue and instead promote quackery like AA which has horrible outcomes.
What I meant was, do the same people who have that "moralistic and individualistic worldview" and reject lead as a possible cause of things believe (or rather disbelieve?) the same things about alcohol?
I'm sure we've all seen alcohol or illicit drug use used to further the morality tales we tell ourselves.
Lead is a lot harder to do it with because it was in water or paint.
Lead is a lot harder to do it with because it was in water or paint.
If you want a morality tale it's the worst because it means a the perps were originally helpless victims themselves.
The worse thing I think comes from some really old chemistry books from the early 1900's I inherited. The thing from those books is educated people back when they started putting lead in paint and gasoline absolutely knew lead caused developmental brain damage.
The worse thing I think comes from some really old chemistry books from the early 1900's I inherited. The thing from those books is educated people back when they started putting lead in paint and gasoline absolutely knew lead caused developmental brain damage.
I think you're ignoring the point the article is trying to make because the lead-crime hypothesis is one that is likeable- it's a simple cause-and-effect that we can (and did) remedy.
The point they are making is that selection bias in which studies get published and which get suppressed can fool us (and may have done so) into believing an effect is real that isn't, or into thinking an effect is much larger than it is. Forget about which study this is and look at the point they are making on its own. Is there bad science going on here?
> but the mass media reaction to it just shows how much is wrong with our society
There is a whole other branch of mass media that desperately wants the lead-crime hypothesis to be not just true but the only reason for the crime rate falling in the 90s. Why? because it's much preferred over the alternative answer: Roe vs Wade. That side of the mass media is very aggressive in defending the lead-crime hypothesis.
Good discussion on the subject here: https://freakonomics.com/podcast/abortion/
The point they are making is that selection bias in which studies get published and which get suppressed can fool us (and may have done so) into believing an effect is real that isn't, or into thinking an effect is much larger than it is. Forget about which study this is and look at the point they are making on its own. Is there bad science going on here?
> but the mass media reaction to it just shows how much is wrong with our society
There is a whole other branch of mass media that desperately wants the lead-crime hypothesis to be not just true but the only reason for the crime rate falling in the 90s. Why? because it's much preferred over the alternative answer: Roe vs Wade. That side of the mass media is very aggressive in defending the lead-crime hypothesis.
Good discussion on the subject here: https://freakonomics.com/podcast/abortion/
I think leaded gasoline influence on crime rates was observed in countries where abortion was illegal until different date and influence was as strong as in the US.
Yes. Information from other countries with different dates of phasing out lead would be (and is) strong evidence for the lead crime hypothesis, and evidence against the racier abortion hypothesis that the Freakonomics guys also promoted. This meta-analysis just gives up on cross-borders comparisons entirely.
And they suspiciously focused on murder only, they may have peeked at the data before deciding.
And they suspiciously focused on murder only, they may have peeked at the data before deciding.
One of the many problems with the abortion-crime hypothesis is that it is US-specific. For example, in Romania the government banned abortion in 1966 and instituted harsh punishments for illegal abortions. Yet no one has shown that this correlated with a crime wave in the late 1980s as one would expect if free abortions really decreases crime.
There are other variables too. Soviet dictatorships were pretty safe, because they were totalitarian surveillance "fake it till you make it" "smile and nobody gets hurt" dystopias.
Theoretically the connection is sound (so I think it warrants a pretty solid prior probability), after all unwanted children lead to decrease in socioeconomic status, which is a very surefire way to have a lot of problems in life, and without a supportive family and state, the number of options quickly dwindles to illegal and not so great ones. (Basically the "not so great" option is that in the Soviet dictatorships around here - Eastern Europe - at least the full employment mandate meant that there was enough make believe work available to not starve. )
Theoretically the connection is sound (so I think it warrants a pretty solid prior probability), after all unwanted children lead to decrease in socioeconomic status, which is a very surefire way to have a lot of problems in life, and without a supportive family and state, the number of options quickly dwindles to illegal and not so great ones. (Basically the "not so great" option is that in the Soviet dictatorships around here - Eastern Europe - at least the full employment mandate meant that there was enough make believe work available to not starve. )
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> You see there are no studies disproving this theory therefore there must be studies disproving this theory, therefore this theory is wrong.
That is an oversimplification, and I think it's in the original article. Let me try to give an alternative explanation.
In an ideal world where all the studies have the same amount of subjects and all the countries have the same conditions, when you make an histogram of the result of the test you expect to see a Gaussian distribution. Some graphics in https://en.wikipedia.org/wiki/Normal_distribution
If half of the studies have 100 participants and the other half have 10000 participants, you expect to see the sum of two Gaussian distributions with the same center, it looks like a low wide mountain with a bump in the center. In a more realistic universe, each study has a different number of participants, and you get something in between. A rounded symmetrical bump.
Also, in a magical world where there are two type of countries, you will see the sum of two bumps with different centers. If they were far enough, you would see two humps. If they were too close, you will see only one hump but wider than the expected only form noise. And in between you can get weird shapes.
In a realistic word where each country is unique, and they are not so different, you get a bump. With enough variations, some luck, and crossing your fingers, you expect to see a bump that is similar to a Gaussian. It's not exactly a Gaussian, but somewhat close enough. More technical details in https://en.wikipedia.org/wiki/Central_limit_theorem
So if you have a very big number of studies, you expect to see in the histogram something like a Gaussian. In the first graph, instead of the histogram, the article uses another representation. In an ideal word, you expect to see an inverted ʃ. See again https://en.wikipedia.org/wiki/Normal_distribution
In a real word you expect to see something somewhat similar to an inverted ʃ. But the graphic shows only a L, Where is the top horizontal part of the inverted ʃ???
It's a very difficult question, and it's difficult to understand without a deep analysis. (That I can't do.) Perhaps there are good reasons, but it's strange.
In particular, the vertical part of the inverted ʃ in the graphic is close to 0, too close to 0. You can see that the lower tic of the inverted ʃ goes quite a bit to the right, so the "missing" upper tic should go approximately the same distance to the left. (Or there must be an explanation. Not all distributions are symmetrical, but it's strange that it's so asymmetrical.)
Now, the "missing" experiments in the "missing" upper tic of the inverted ʃ are the ones that say that the hypothesis is wrong (or even that lead is good for you). So it would be nice to have an explanation of thee weird distribution or the disappearance of these experiments.
Oversimplifying, there are no studies disproving this theory, but from the distribution there should be studies disproving this theory, therefore there is something weird happening here.
(Note: Sometimes the vertical part of the inverted ʃ is so far away from 0 that you don't expect any result in the negative part. Just the two tics at the top and at the bottom of the inverted ʃ, both in the positive part.)
That is an oversimplification, and I think it's in the original article. Let me try to give an alternative explanation.
In an ideal world where all the studies have the same amount of subjects and all the countries have the same conditions, when you make an histogram of the result of the test you expect to see a Gaussian distribution. Some graphics in https://en.wikipedia.org/wiki/Normal_distribution
If half of the studies have 100 participants and the other half have 10000 participants, you expect to see the sum of two Gaussian distributions with the same center, it looks like a low wide mountain with a bump in the center. In a more realistic universe, each study has a different number of participants, and you get something in between. A rounded symmetrical bump.
Also, in a magical world where there are two type of countries, you will see the sum of two bumps with different centers. If they were far enough, you would see two humps. If they were too close, you will see only one hump but wider than the expected only form noise. And in between you can get weird shapes.
In a realistic word where each country is unique, and they are not so different, you get a bump. With enough variations, some luck, and crossing your fingers, you expect to see a bump that is similar to a Gaussian. It's not exactly a Gaussian, but somewhat close enough. More technical details in https://en.wikipedia.org/wiki/Central_limit_theorem
So if you have a very big number of studies, you expect to see in the histogram something like a Gaussian. In the first graph, instead of the histogram, the article uses another representation. In an ideal word, you expect to see an inverted ʃ. See again https://en.wikipedia.org/wiki/Normal_distribution
In a real word you expect to see something somewhat similar to an inverted ʃ. But the graphic shows only a L, Where is the top horizontal part of the inverted ʃ???
It's a very difficult question, and it's difficult to understand without a deep analysis. (That I can't do.) Perhaps there are good reasons, but it's strange.
In particular, the vertical part of the inverted ʃ in the graphic is close to 0, too close to 0. You can see that the lower tic of the inverted ʃ goes quite a bit to the right, so the "missing" upper tic should go approximately the same distance to the left. (Or there must be an explanation. Not all distributions are symmetrical, but it's strange that it's so asymmetrical.)
Now, the "missing" experiments in the "missing" upper tic of the inverted ʃ are the ones that say that the hypothesis is wrong (or even that lead is good for you). So it would be nice to have an explanation of thee weird distribution or the disappearance of these experiments.
Oversimplifying, there are no studies disproving this theory, but from the distribution there should be studies disproving this theory, therefore there is something weird happening here.
(Note: Sometimes the vertical part of the inverted ʃ is so far away from 0 that you don't expect any result in the negative part. Just the two tics at the top and at the bottom of the inverted ʃ, both in the positive part.)
That’s all well and good but it assumes studies get published independent of their results, even if they fly in the face of established fact. In reality, hundreds of thousands of studies are conducted, the author realizes they screwed up immensely and will be laughed out of the room if they publish saying they found, say, seeing a zebra once in your life is enough to account for dying twenty years younger on average, or that lead exposure is actually good for you, and won’t publish the study. This’ll even happen mid-study once discouraging results are found. That self-censorship/sanity checking is probably more than enough to account for the statistical “anomaly” you are observing, no?
The blog post author discusses that point and dismisses it. The lead-crime hypothesis is big in the world of Criminology and a statistical study finding no correlation between lead and crime most certainly would get published. For certain, there is a publication bias against negative results but it is not at all clear why it would apply in this case. Furthermore, statistical studies can take many man-years to conduct so why would the study authors throw away all that work rather than attempting to publish a negative result?
There is also the "faster than light neutrinos effect". It the result was true, the authors would get a Nobel price. If it was false, the authors would look like morons. So they decided to publish the FTL-neutrinos result informally, and as asking help, and with a lot of caveats. If it was true, they'd get their Nobel anyway. If false, they were just asking for help debugging a strange unexpected result.
In less interesting problems, the authors may decide to just not publish it.
In political areas, it's a risk that the far-right or far-left decides to support your preprint and later when you find the error claim that Big Something paid you to suppress the true. And the other side to claim that you are a far-other-side supporter.
In less interesting problems, the authors may decide to just not publish it.
In political areas, it's a risk that the far-right or far-left decides to support your preprint and later when you find the error claim that Big Something paid you to suppress the true. And the other side to claim that you are a far-other-side supporter.
Yes, that's my guess, and is the explanation in the research paper.
https://en.wikipedia.org/wiki/Publication_bias
https://en.wikipedia.org/wiki/Reporting_bias
https://en.wikipedia.org/wiki/Media_bias
https://en.wikipedia.org/wiki/Publication_bias
https://en.wikipedia.org/wiki/Reporting_bias
https://en.wikipedia.org/wiki/Media_bias
I came to say something similar. I understand the impulse to complain that it is an argument from absence of evidence, but the statistical reasoning behind these kind of arguments is sound. The real question, I guess, is whether the conclusion is justified, given the found effect sizes and distribution of results.
OTOH, this meta-analysis was published, showing a negative result ...
Based on the blog post, I'm most concerned about the focus on murder rather than violence more generally.
OTOH, this meta-analysis was published, showing a negative result ...
Based on the blog post, I'm most concerned about the focus on murder rather than violence more generally.
Isn't murder used simply because that's the most reliable signal (proxy) of violence?
All murder is violence. But reliable proxy of over-all violence? Well,
# of violent incidents >>>> # of violent incidents that are also murder
So there really might not be enough murders to do the statistical inferences you want to do. Also, if there is a qualitative difference between murder and other violence, not merely a quantitative difference in degree, then it might get at the wrong things. Like, sometimes people go into a violent rage, and occasionally those end up killing some one. OTOH, sometimes people, say, rob a store, get scared, and shoot, and that's murder too. And then there are the people who carefully plan a murder to get something they want. Those all seem like they involve different kinds of brain states...
# of violent incidents >>>> # of violent incidents that are also murder
So there really might not be enough murders to do the statistical inferences you want to do. Also, if there is a qualitative difference between murder and other violence, not merely a quantitative difference in degree, then it might get at the wrong things. Like, sometimes people go into a violent rage, and occasionally those end up killing some one. OTOH, sometimes people, say, rob a store, get scared, and shoot, and that's murder too. And then there are the people who carefully plan a murder to get something they want. Those all seem like they involve different kinds of brain states...
Does it mean that some studies should arrive at false result due to random errors in methodology and in peer review process?
Maybe affect is so strong that to get opposite result you'd have to botch so many things that your chances of getting through peer review are so low that not a single wrongly successful research debunking this made it through peer review. Probably not many people are trying to debunk it and those that failed to prove it don't publish because people don't like publishing negative results.
Maybe affect is so strong that to get opposite result you'd have to botch so many things that your chances of getting through peer review are so low that not a single wrongly successful research debunking this made it through peer review. Probably not many people are trying to debunk it and those that failed to prove it don't publish because people don't like publishing negative results.
False results, yes, but it doesn't have to be due to mistakes but can also be due to innocent unlucky sampling.
If the effect is so strong that hardly ever happens, then it should also be so strong that there aren't many papers showing only a weak effect, but there's a huge amount of them. Maybe they're all botched but got published because their results agreed with the accepted idea whereas a contrarian botched paper would get more scrutiny and be rejected?
If the effect is so strong that hardly ever happens, then it should also be so strong that there aren't many papers showing only a weak effect, but there's a huge amount of them. Maybe they're all botched but got published because their results agreed with the accepted idea whereas a contrarian botched paper would get more scrutiny and be rejected?
Why doesn't the absence of "lead is good" data simply mean that your model is flawed?
Yes, that is one possibility. Not all distribution have an inverted ʃ shape in this graph. In particular, the exponential distribution is very different and very asymmetric, but nobody expect an exponential distribution in a group of studies like this.
Also, "my" model is an informal version of the model used in the research paper. You can read there an explanation with more technical details and more accurate.
Also, "my" model is an informal version of the model used in the research paper. You can read there an explanation with more technical details and more accurate.
Another possibility is that people just don't like such reductive explanations of human behavior. It's easier to say, well, violent youth is a product of society somehow and it's too hard to come up with a concrete explanation.
I think many people are uncomfortable with the idea that a chemical or unknown environmental change can cause such marked changes in human behavior.
To be even more accurate the older folks are uncomfortable with provable allegations that they are brain damaged.
I also feel like there is a very short jump from the lead crime hypothesis to a lead political dysfunction hypothesis. Meaning older voters and politicians have poor critical thinking ability and poor impulse control. Which causes them to make bad political decisions.
A really well done published study showed gray matter shrinkage in people with COVID-19. I assume, and hope, that they'll do a follow up to see if they recover. I am genuinely curious whether we might see a bump in some kind of problems (depression, suicide, crime, etc.). Seeing how the US 2019-2020's politics has gone ...
https://www.medrxiv.org/content/10.1101/2021.06.11.21258690v...
https://www.medrxiv.org/content/10.1101/2021.06.11.21258690v...
There’s no real evidence to believe that the difference between COVID-19 and other coronaviruses is anything other than a matter of magnitude/degrees (more infectious, more lethal, more resistant) rather than “super mysterious disease with never-before-seen implications.” There is a huge incentive to try to find and publish studies suggesting otherwise, but take them with considerable skepticism.
This study was very well done, the people on the study very well regarded in the field; I believe the results. That they found the most shrinkage in olfactory regions is consistent with one of the most common symptoms.
As for whether this is a matter of degree rather than kind, there frankly have not been enough studies done of pre-post illness, and there should be. I know that depression is common in cases of severe pneumonia, and maybe there is a loss of gray matter in those cases too.
As for whether this is a matter of degree rather than kind, there frankly have not been enough studies done of pre-post illness, and there should be. I know that depression is common in cases of severe pneumonia, and maybe there is a loss of gray matter in those cases too.
I was actually saying the same thing. I too read that study and was not trying to knock it. My point though was that if we study any of the other conditions this closely, we might see the same things - so it doesn’t make me believe that we’ll see too much novelty in the fallout from COVID because people succumb to then recover from the cold and flu all the time, they’re just not as heavily scrutinized.
This is my favourite part of the theory. The people who were 20/30/40 years old in the 1970/80s are now 60/70/80.
It's a bit difficult to commit violent crime at that age.
Yet it's easy to sit on the internet posting and believing in outright insanity and extremism.
It will take until 2040+ for many of these people to leave the political system.
It's a bit difficult to commit violent crime at that age.
Yet it's easy to sit on the internet posting and believing in outright insanity and extremism.
It will take until 2040+ for many of these people to leave the political system.
What it is is that 'violent youth is a product of society' has an agenda. People are using crime to push particular agendas.
If it turns out that lead exposure the culprit the throws a big monkey wrench in that.
Random thought as well, what if it turns out that the rise in obesity and type II diabetes is due to something similar?
If it turns out that lead exposure the culprit the throws a big monkey wrench in that.
Random thought as well, what if it turns out that the rise in obesity and type II diabetes is due to something similar?
HN recently discussed an article arguing that obesity in the United States apparently rolls downhill, with little at high altitude and a great deal at sea level. The inference being that water-borne pollutants may be the cause of obesity.
Maybe because it suggests our elites have brain damage making them more likely to have poor impulse control.
I believe you are onto something here. See all those inner city neighborhoods, ghettos, and other slum areas? Nine times out of then, what are surrounding them? Highways? There couldn't be a connection, could there?! And let's not talk about all the racists who blame crime on immigration. What are they gonna do if it turns out violent crime often is caused by pollution-induced brain damage rather than defective genes of foreigners?
In the USA, “inner-city” is where the “slums” are, but in many places around the world, it’s the opposite. For example, France is famous for having undesirable suburbs and safer/cleaner/richer “inner city.”
The crime levels in metropolitan areas can vary significantly by the neighbourhood though, and some cities have very low levels of crime.
I’m not suggesting pollution doesn’t have any correlation to crime (it probably does) but it doesn’t seem to be one of the more significant factors if you wanted to try to explain why some neighbours / populations commit more crime.
I’m not suggesting pollution doesn’t have any correlation to crime (it probably does) but it doesn’t seem to be one of the more significant factors if you wanted to try to explain why some neighbours / populations commit more crime.
But air pollution's impact on cognition is a well-studied topic. See e.g: https://www.pnas.org/content/115/37/9193, https://www.sciencedirect.com/science/article/pii/S019701862..., and especially https://jech.bmj.com/content/64/3/223.short: "Although results were not statistically significant, the associations found between exposure to NO2 and cognitive functions suggest that traffic-related air pollution may have an adverse effect on neurodevelopment, especially early in life, even at low exposure levels." In other words, air pollution makes you dumb and being male and dumb makes you more prone to commit crime. I find no reason not to believe that this may be a significant factor.
It's not racist to point out higher amount of crime among many migrant populations. Often such populations are poorer and less educated than general population, both of which are attributes that correlate with higher crime rate, and also ones mostly determined by your parents wealth rather than your own actions.
I didn't say it was racist and it is not necessarily racist. Just as it isn't racist to point out the higher amount of crime among many young male populations. Often such populations are poorer and less educated than general population, both of which are attributes that correlate with higher crime rate.
> The lead-crime hypothesis is almost certainly true
Could you explain what is true? You are talking about a societal wide chemical change in behaviour in all aspects of life.
To start, what % or amount of the reduced crime is due to the lead-crime hypothesis?
Since the lead has brain damaged somewhat equally everyone's impulse control can we see this in TV viewing habits and other everyday behaviour? I'd expect if it can cause us to murder more, it'd also have many everyday effects.
Do you have any conversations around it's effects on other animals also in these environments. How would our pets changed or city animals like birds have changed their behaviour?
Societal wide chemical changes are pretty out there, but they happen, IQs rise as countries become richer through diverse food security but this a limit function, 90% of people get enough iodine so the IQ changes will on be the 10%. Lead-crime hypothesis is ~100% changed.
The Middle East was late to reducing lead. Do the think the we will see more stability there. Do you think lead-crime hypothesis is that important? What is true?
Could you explain what is true? You are talking about a societal wide chemical change in behaviour in all aspects of life.
To start, what % or amount of the reduced crime is due to the lead-crime hypothesis?
Since the lead has brain damaged somewhat equally everyone's impulse control can we see this in TV viewing habits and other everyday behaviour? I'd expect if it can cause us to murder more, it'd also have many everyday effects.
Do you have any conversations around it's effects on other animals also in these environments. How would our pets changed or city animals like birds have changed their behaviour?
Societal wide chemical changes are pretty out there, but they happen, IQs rise as countries become richer through diverse food security but this a limit function, 90% of people get enough iodine so the IQ changes will on be the 10%. Lead-crime hypothesis is ~100% changed.
The Middle East was late to reducing lead. Do the think the we will see more stability there. Do you think lead-crime hypothesis is that important? What is true?
That's just wishful thinking. The costs on health could be massive if lead is essential. (and it very likely is)
> I don't get this. If, say, the actual effect of lead on crime is 0.33 on their scale (a "large" effect size) then you'd expect to find papers clustered around that value
You'd expect them to be clustered around that value symmetrically, right? That's clearly not the case in the diagram that the blog post author quoted. There's a cluster around very weak positive effects, and then a long tail of strong positive effects but no matching long tail of weak negative ones. This suggests either that the negative results were truncated out, negative results have been hacked to positive ones, or there is some confounding factor at play. And I think the modeling in the paper is just an attempt at finding the confounding factor, and not finding one.
That said, the author's arguments around negative results being publishable in this field + studies not disappearing seem pretty strong.
(Or, at least this is my reading of the situation as a total amateur.)
You'd expect them to be clustered around that value symmetrically, right? That's clearly not the case in the diagram that the blog post author quoted. There's a cluster around very weak positive effects, and then a long tail of strong positive effects but no matching long tail of weak negative ones. This suggests either that the negative results were truncated out, negative results have been hacked to positive ones, or there is some confounding factor at play. And I think the modeling in the paper is just an attempt at finding the confounding factor, and not finding one.
That said, the author's arguments around negative results being publishable in this field + studies not disappearing seem pretty strong.
(Or, at least this is my reading of the situation as a total amateur.)
> You'd expect them to be clustered around that value symmetrically, right?
I'm not sure. This is a safe assumption if you don't know anything about anything, but I bet it's possible to construct or simulate scenarios where the hypothesis is "true" and where you also see the distribution of effect sizes shown here.
I'm not sure. This is a safe assumption if you don't know anything about anything, but I bet it's possible to construct or simulate scenarios where the hypothesis is "true" and where you also see the distribution of effect sizes shown here.
> This suggests either that the negative results were truncated out, negative results have been hacked to positive ones, or there is some confounding factor at play.
Here's a potential confounding factor: maybe the cluster of very weak positive effects includes some studies that initially showed very weak negative effects but that had their methodology tweaked to avoid showing an "impossible" result. (I don't think anyone argues that atmospheric lead _decreases_ crime rates.)
If so, that would mean that there are some "missing" negative studies, but that there are also "too many" zero/very low result studies. If corrected for that, I suspect that the meta-analysis would show a positive effect size, though lower than 0.33.
Here's a potential confounding factor: maybe the cluster of very weak positive effects includes some studies that initially showed very weak negative effects but that had their methodology tweaked to avoid showing an "impossible" result. (I don't think anyone argues that atmospheric lead _decreases_ crime rates.)
If so, that would mean that there are some "missing" negative studies, but that there are also "too many" zero/very low result studies. If corrected for that, I suspect that the meta-analysis would show a positive effect size, though lower than 0.33.
That's the "negative effects hacked to positive ones" explanation.
> I don't think anyone argues that atmospheric lead _decreases_ crime rates.
Although in principle I don't see why it couldn't be the case, as leas poisoning also has symptoms such as depression and fatigue, which could marginally sway people towards inaction.
Although in principle I don't see why it couldn't be the case, as leas poisoning also has symptoms such as depression and fatigue, which could marginally sway people towards inaction.
"lead poisoning also has symptoms such as depression and fatigue, which could marginally sway people towards inaction."
That could be counteracted by stimulant use, for example.
That could be counteracted by stimulant use, for example.
What is the point you are trying to make? I don't quite see how your comment fits into the overall topic, re: lead based crime.
Let me spell it out:
If it's true that lead exposure motivates crime, but at the same time causes people to feel too depressed and fatigued to act on their motivation, then my point is that if lead-exposed people then take stimulants (like meth, coke, or crack, for example) then those stimulants could counteract the depression and fatigue effects of the lead enough to allow people to act on their motivation to commit crime.
In case some of the downvoters are skeptical that stimulants could counteract depression or fatigue -- they certainly can. Not saying this is a smart thing to do, due to the addictive potential of these substances or their other deleterious effects. But they certainly can stimulate people in to action if they're otherwise too depressed or tired to do anything.
This is just a hypothesis. But it would be interesting to see if there's a correspondence between lead exposure, stimulant use, and crime.
The nexus of lead exposure, alcohol, and crime would also be interesting to investigate, as alcohol is already well known to be associated with violence, impulsive behavior, and poor decision making -- adding lead exposure in to the mix might potentiate this in to criminal activity.
If it's true that lead exposure motivates crime, but at the same time causes people to feel too depressed and fatigued to act on their motivation, then my point is that if lead-exposed people then take stimulants (like meth, coke, or crack, for example) then those stimulants could counteract the depression and fatigue effects of the lead enough to allow people to act on their motivation to commit crime.
In case some of the downvoters are skeptical that stimulants could counteract depression or fatigue -- they certainly can. Not saying this is a smart thing to do, due to the addictive potential of these substances or their other deleterious effects. But they certainly can stimulate people in to action if they're otherwise too depressed or tired to do anything.
This is just a hypothesis. But it would be interesting to see if there's a correspondence between lead exposure, stimulant use, and crime.
The nexus of lead exposure, alcohol, and crime would also be interesting to investigate, as alcohol is already well known to be associated with violence, impulsive behavior, and poor decision making -- adding lead exposure in to the mix might potentiate this in to criminal activity.
>If it's true that lead exposure motivates crime, but at the same time causes people to feel too depressed and fatigued to act on their motivation
But people seem more sedentary and depressed than ever before. Animal studies show the same - the controls are less active than the exposed group.
Maybe you only made people too weak to be capable of any violent crime.
But people seem more sedentary and depressed than ever before. Animal studies show the same - the controls are less active than the exposed group.
Maybe you only made people too weak to be capable of any violent crime.
"But people seem more sedentary and depressed than ever before. Animal studies show the same - the controls are less active than the exposed group."
Well, you need to post this reply to the person I was replying to instead of to me, as it was their contention that "lead poisoning also has symptoms such as depression and fatigue, which could marginally sway people towards inaction."
Well, you need to post this reply to the person I was replying to instead of to me, as it was their contention that "lead poisoning also has symptoms such as depression and fatigue, which could marginally sway people towards inaction."
We already have a strong list of ways lead poisoning can increase crime. When someone is brainstorming to try to find some possible way it could possibly decrease crime, you don't need to point out more ways those reasons could cause increases.
What?
I was responding to someone who said "lead poisoning also has symptoms such as depression and fatigue, which could marginally sway people towards inaction."
What I just quoted is an argument against lead being implicated in an increase in crime. I was just pointing out why lead might be implicated in crime after all, despite the above quoted argument against it.
So what exactly am I doing wrong here?
I was responding to someone who said "lead poisoning also has symptoms such as depression and fatigue, which could marginally sway people towards inaction."
What I just quoted is an argument against lead being implicated in an increase in crime. I was just pointing out why lead might be implicated in crime after all, despite the above quoted argument against it.
So what exactly am I doing wrong here?
Because they already know there are lots of arguments for lead to cause an increase. The part you quoted was them reaching on purpose to come up with an argument that could even possibly go the other way.
They already know it's likely wrong. You pointing out it could be wrong isn't needed. They already know there are lots of anti-lead arguments, so you making another one isn't needed.
They already know it's likely wrong. You pointing out it could be wrong isn't needed. They already know there are lots of anti-lead arguments, so you making another one isn't needed.
OK, I see what you are trying to suggest, but how are you getting there? It sort of feels like you've already decided that stimulants need to be part of the equation and are trying to shoehorn it in.
What makes you think that?
I was just throwing an idea out there. I'm not convinced of anything.
I was just throwing an idea out there. I'm not convinced of anything.
> I don't think anyone argues that atmospheric lead _decreases_ crime rates.
Scientists wouldn't have to argue this. They could just argue the null hypothesis as the results were really close to 0.
Scientists wouldn't have to argue this. They could just argue the null hypothesis as the results were really close to 0.
I don’t know much about stats, but the idea that a theory is bunk because no studies have shown it’s bunk is pretty absurd. How many studies fail to show an association between narcotics abuse and crime? Zero? Then it must be fake?
I think their argument is a little more subtle than that -- the issue isn't really that there are no negative results, but rather that the shape of the distribution of results is funny.
They're saying you'd expect the results to follow a normal distribution centered at some value. Instead, we see a large number of studies clustered just above zero and a right tail, but no left tail. I think they're arguing that this is because the left side of the distribution is unpublished, and without knowing what it looks like, you can't come to a conclusion.
They're saying you'd expect the results to follow a normal distribution centered at some value. Instead, we see a large number of studies clustered just above zero and a right tail, but no left tail. I think they're arguing that this is because the left side of the distribution is unpublished, and without knowing what it looks like, you can't come to a conclusion.
Let’s say there’s a test that, by pure chance, has a probability of p=1/N of returning an unexpected outcome. If we run that test N times, we expect on average one unexpected outcome, solely due to random chance.
I haven’t read the linked paper yet, but its authors’ argument is that they have orthogonal evidence that p in this case should be considerably larger than 1/24, so given 24 total studies on the lead crime hypothesis, at least one should have returned a negative result purely by chance.
The validity of this claim depends entirely on whether their argument that p>>1/24 is sound.
I haven’t read the linked paper yet, but its authors’ argument is that they have orthogonal evidence that p in this case should be considerably larger than 1/24, so given 24 total studies on the lead crime hypothesis, at least one should have returned a negative result purely by chance.
The validity of this claim depends entirely on whether their argument that p>>1/24 is sound.
Though even if it's 1/12, the chance of no negative results by chance is still >10%, right?
Picture a perfect bell curve where the whole left half has been chopped off. If you had an a priori reason to believe it’s a bell curve, then it’s easy to spot the fact that the left half has been chopped off, and easy to spot where the mean would have been.
> This means that 22 out of 24 studies found positive associations.
> The authors present a model that says there should be more papers showing negative effects just by chance.
To the layperson it sure looks like the lead-crime hypothesis is confirmed. Really curious to see a more in-depth follow-up on this meta-analysis.
> The authors present a model that says there should be more papers showing negative effects just by chance.
To the layperson it sure looks like the lead-crime hypothesis is confirmed. Really curious to see a more in-depth follow-up on this meta-analysis.
It's interesting because, as I understand it (based solely on the article's summary), the meta-analysis asserts that the current lead-crime value is wrong. Either it is much lower than expected because we should see more ambiguous papers and the lack of them points to bias in the study/publish methodology -or- its much stronger than expected because we cannot find many counterexamples. The original publishers just went with the first, the article asserts the second.
I think both conclusions are wrong.
Since this is a meta-study, drawing conclusions from the absence of null-results and the absence of clustering is prone to a lot of confounders. The article mentions publication-bias, where non-null-results are published with a higher probability. Other such confounders will exist, e.g. data-availability-bias in certain places and populations, location-bias because researchers study their usually first-world, urban, university-town surroundings more often. Community-bias, because researchers tend to cluster and get inspiration for new studies from their community and peer group on the conferences they visit. Data-similarity-bias, because they can only compare studies where data can be normalized to a common base. Quality-bias, because they necessarily include well-done and badly-done studies, in different amounts, usually without weighing them properly, because that is very hard to do.
Most of those confounders cannot be corrected for. So one could draw a conclusion like "we do see null-results in the expected amount and clustering in the expected amount, therefore the result of this meta-study is a confirmation of the lead-crime-hypothesis". But the only correct opposite conclusion is "we do not see null-results and clustering in the expected amount, so our result is 'we do not know'".
So the imho correct interpretation of the meta-study is "don't know, further research or better meta-analysis needed".
Since this is a meta-study, drawing conclusions from the absence of null-results and the absence of clustering is prone to a lot of confounders. The article mentions publication-bias, where non-null-results are published with a higher probability. Other such confounders will exist, e.g. data-availability-bias in certain places and populations, location-bias because researchers study their usually first-world, urban, university-town surroundings more often. Community-bias, because researchers tend to cluster and get inspiration for new studies from their community and peer group on the conferences they visit. Data-similarity-bias, because they can only compare studies where data can be normalized to a common base. Quality-bias, because they necessarily include well-done and badly-done studies, in different amounts, usually without weighing them properly, because that is very hard to do.
Most of those confounders cannot be corrected for. So one could draw a conclusion like "we do see null-results in the expected amount and clustering in the expected amount, therefore the result of this meta-study is a confirmation of the lead-crime-hypothesis". But the only correct opposite conclusion is "we do not see null-results and clustering in the expected amount, so our result is 'we do not know'".
So the imho correct interpretation of the meta-study is "don't know, further research or better meta-analysis needed".
Don't forget outright fraud.
https://news.ycombinator.com/item?id=27884233
https://news.ycombinator.com/item?id=27884233
not really. the lead-crime hypothesis posits that the reduction of crime in the 90s is due to the reduction of lead, but if the effect is really tiny, which the paper suggests, then it likely means that other factors, such as increased incarceration and or accessibility to abortion, may also be to blame for falling crime, or something else entirely.
Well, we're not "post-lead" anyway. Particularly in larger, older cities there is a lot of lead paint around, and this tends to be clustered in older, poorer neighborhoods with unrenovated and more poorly maintained dwellings. I'm not sure this is a good meta analysis.
And there are other neurotoxic compounds still in common use, such as mercury-aluminium-amalgam for cheap dental work. That would also confound all the simple studies. I'm afraid there can't be a firm conclusion without an in-depth study of heavy metal prevalence in bloodstream and bones vs. criminal behavior. Just plotting sales figures of leaded gas vs. murder rates doesn't say anything. Any more elaborate study is of course smaller and more expensive, so won't be done as easily.
they still use that? even when it's a known neurotoxin?
I had the impression (although I can't remember where from)
that amalgam fillings were surprisingly benign.
They're small, leach surprisingly little, and what they do leach is in a form that isn't readily bio-available.
Which isn't to say they're completely harmless, just not so bad as you might expect.
They're small, leach surprisingly little, and what they do leach is in a form that isn't readily bio-available.
Which isn't to say they're completely harmless, just not so bad as you might expect.
Your impression is correct. The mercury is quite chemically bound.
The caveat is that when it is removed, it may not be so bound.
The caveat is that when it is removed, it may not be so bound.
makes sense thanks for sharing
[deleted]
Very few dentists in USA use amalgam, and certainly not on patients who don't already have amalgam such as children. The moment one orders amalgam one starts getting letters from EPA inquiring about the status of one's very expensive evacuation air amalgam separator. (It's true that everything dentists buy is expensive, but that's not a reason to seek out something else to have to buy.) Properly applied composite fillings have retention nearly as good as amalgam, and of course much better appearance.
My insurance only covers amalgam. If that is common, then those without the means to pay the difference are likely to end up with amalgam.
In practice, that's a way to reduce claims rather than a way to encourage a particular filling material.
Another downside to amalgam fillings is that they require more drilling (and thus more tooth removal) than composite fillings.
Also avgas still mostly has lead in it: https://en.wikipedia.org/wiki/Avgas
Just a couple of days ago we discussed the first approved 100 octane unleaded avgas. One hopes this can scale up quickly and replace the leaded 100LL.
https://news.ycombinator.com/item?id=27983845
https://news.ycombinator.com/item?id=27983845
With as conservative as aviation is, and as long as airplanes last, I doubt anything about it will be quick. I’m amazed it has taken this long to get a single approved 100LL replacement, considering high octane unleaded fuels have existed for decades.
> With as conservative as aviation is, and as long as airplanes last, I doubt anything about it will be quick.
You may well be right.
> I’m amazed it has taken this long to get a single approved 100LL replacement, considering high octane unleaded fuels have existed for decades.
Outside of some specialized racing fuels, no. And nothing fulfilling the other requirements (distillation curve, vapour pressure, etc etc) of 100 octane aviation gasoline (this is measured with the MON procedure, as opposed to RON or AKI you'll find at your local gas station) at somewhat reasonable cost has previously been introduced.
I think the reasons why it has taken so long are 1) it's a genuinely hard problem 2) it's not a very large market.
You may well be right.
> I’m amazed it has taken this long to get a single approved 100LL replacement, considering high octane unleaded fuels have existed for decades.
Outside of some specialized racing fuels, no. And nothing fulfilling the other requirements (distillation curve, vapour pressure, etc etc) of 100 octane aviation gasoline (this is measured with the MON procedure, as opposed to RON or AKI you'll find at your local gas station) at somewhat reasonable cost has previously been introduced.
I think the reasons why it has taken so long are 1) it's a genuinely hard problem 2) it's not a very large market.
I’m aware that it’s MON (there are race fuels above 100 MON) and that there are different requirements for operating at altitude. Obviously it’s a specific application with specific requirements.
I think the problem would have been solved a lot sooner if there was any urgency to switch, either by the people buying it, or by regulators.
The switch with automotive fuels was easy. Cars are disposable by comparison and regulators banned lead-burning ones out of existence.
I think the problem would have been solved a lot sooner if there was any urgency to switch, either by the people buying it, or by regulators.
The switch with automotive fuels was easy. Cars are disposable by comparison and regulators banned lead-burning ones out of existence.
Interestingly here it's the wealthier inner-city suburbs where lead paint was commonly used when the houses were built.
Advice seems to be leave it alone unless it's flaking.
Advice seems to be leave it alone unless it's flaking.
My experience here mirrors that. I just assumed that the lead paint was more expensive and the builders of my old multi-family went with duller paints. No lead to be found!
[deleted]
Lead paint is not an immediate issue unless it is flaking or someone does something to it.
Yeah, the elephant in the room is leaded gasoline insofar as the lead-crime hypothesis is concerned. Unlike paint, lead in the exhaust spreads out across the entire community in a form that can be easily inhaled.
> In fact, because the sample size for homicides is so small, exactly the opposite is true. In general, studies that look at homicide rates in the '80s and '90s simply don't have the power to be meaningful. The unit of study should always be an index value for violent crime and it should always be over a significant period of time.
Homicide rates are used for good reasons: they are least subject to reporting variations, they are hardest to fudge, and it’s the most serious crime.
Some evidence against the lead-crime hypothesis is the recent (2020-2021) jump in homicides in the U.S.
Homicide rates are used for good reasons: they are least subject to reporting variations, they are hardest to fudge, and it’s the most serious crime.
Some evidence against the lead-crime hypothesis is the recent (2020-2021) jump in homicides in the U.S.
> Some evidence against the lead-crime hypothesis is the recent (2020-2021) jump in homicides in the U.S.
With a fairly major confounding factor.
The hypothesis was never "lead is the only reason there can ever be a homicide". The loss of 20 million jobs in a blink of an eye might well cause a spike. NYC, for example, is dropping back down. https://www.newsweek.com/shootings-down-june-new-york-police...
With a fairly major confounding factor.
The hypothesis was never "lead is the only reason there can ever be a homicide". The loss of 20 million jobs in a blink of an eye might well cause a spike. NYC, for example, is dropping back down. https://www.newsweek.com/shootings-down-june-new-york-police...
Not a strong evidence for sure but the loss of jobs is not a good explanation either since there hasn’t been a similar jump in homicides in other countries.
That may point to a difference in lockdown policies, safety nets (for example: https://www.nytimes.com/2020/07/03/business/economy/europe-u...), etc. though.
Your initial statement that job losses led to an increase in homicides is not supported by any data though. You’d have to establish this first before we can talk meaningfully about the financial status of households during the pandemic. Also, why would homicides be different than other crimes due to job losses?
Here is data showing that homicides did not go up during the pandemic in other countries: https://www.unodc.org/documents/data-and-analysis/covid/Prop...
Here is data showing that homicides did not go up during the pandemic in other countries: https://www.unodc.org/documents/data-and-analysis/covid/Prop...
The link between economic distress and crime is long established.
Directly contradicted by the data I linked for other countries. In the US, pandemic (expected to be temporary) job losses with extended unemployment, cash grants, and other special programs like the eviction moratorium are not comparable to normal job losses. We know, for example, that the financial situation of the middle class has improved in 2020. And the lack of increase in other crimes also points to other reasons.
> Directly contradicted by the data I linked for other countries.
Other countries handled pandemic aid entirely differently; I even linked to an article highlighting specific cases in the comment you replied to.
"It went up in the US, and not elsewhere" is a good sign the US's recent spikes had nothing to do with lead, in either direction.
Other countries handled pandemic aid entirely differently; I even linked to an article highlighting specific cases in the comment you replied to.
"It went up in the US, and not elsewhere" is a good sign the US's recent spikes had nothing to do with lead, in either direction.
And, you know, gun culture. And a laissez-faire attitude towards other people death in general. I would expect someone to say that people have to take responsibility for their own lead intake, and "people make choices".
> And, you know, gun culture.
You know despite year over year shattering records of gun ownership that homicides with firearms are almost historic lows right?
https://ucr.fbi.gov/crime-in-the-u.s/2019/crime-in-the-u.s.-...
Edit: “Hmm, he sourced direct evidence… but I don’t like this truth”
You know despite year over year shattering records of gun ownership that homicides with firearms are almost historic lows right?
https://ucr.fbi.gov/crime-in-the-u.s/2019/crime-in-the-u.s.-...
Edit: “Hmm, he sourced direct evidence… but I don’t like this truth”
Homicides and crime overall are at almost historic lows globally, for various reasons (see this entire thread).
To prove that gun culture and ownership doesn’t lead to crime, you’d need to show more than the data linked, such as a comparison between countries with strong vs. weak “gun culture” or high vs low gun ownership
To prove that gun culture and ownership doesn’t lead to crime, you’d need to show more than the data linked, such as a comparison between countries with strong vs. weak “gun culture” or high vs low gun ownership
If you are actually interested you can do worse than to look at crime rates vs gun ownership in the Nordic countries, Switzerland, Austria and the Czeck Republic.
Clearly something else than gun ownership / distribution has a massive influence.
I mention ownership / distribution separately above since several of these countries have had fully equipped actual assault rifles like G3 etc (not crippled AR-15s) and ammunition stored in private homes for decades kn addition to huge amounts of hunting rifles, pistols, shotguns and unlicensed guns.
A few suicides a year that's mostly it and removing the guns doesn't seem to work: I haven't heard about a massive drop on suicides since the Norwegians decided to store vital parts of the rifles in local depots.
Clearly something else than gun ownership / distribution has a massive influence.
I mention ownership / distribution separately above since several of these countries have had fully equipped actual assault rifles like G3 etc (not crippled AR-15s) and ammunition stored in private homes for decades kn addition to huge amounts of hunting rifles, pistols, shotguns and unlicensed guns.
A few suicides a year that's mostly it and removing the guns doesn't seem to work: I haven't heard about a massive drop on suicides since the Norwegians decided to store vital parts of the rifles in local depots.
The United States has 4x the number of guns per capita than any of the countries you've listed. Just taking Norway, the rate of handgun ownership is also significantly higher in the US.
It could be the case that below a certain threshold, further reducing firearm availability does little to affect crime, but the US is probably far from that level
It could be the case that below a certain threshold, further reducing firearm availability does little to affect crime, but the US is probably far from that level
I'd rather say that above a certain level it doesn't matter and all these countries are above it.
So it is not about gun ownership but about gun culture abd culture generally.
So it is not about gun ownership but about gun culture abd culture generally.
I would suggest that ownership and “gun culture” are closely related. A gun culture like Norway’s, where there are greater restrictions on registration and purchase of firearms, would probably lead to a reduction in firearms if applied to the US.
Schemes to prevent gun ownership, reduce gun ownership. Shocker.
And control for literally everything else in the world. Unless you want to cherry pick for “effect”.
So instead of the impossible, let’s look at the only the USA’s historic gun violence in the 90s. We add more guns than there has ever been, 40% of all the guns in the world in the USA, crime goes down - we can’t say adding guns was the reason for a crime drop - but we can say it appears adding more guns did not cause more crime.
Unless you have reason to believe crime would have dropped even more in an alternate universe where a magic wand was waved to remove the hundreds of millions of guns in the USA. But, a statement like that should come with evidence.
So instead of the impossible, let’s look at the only the USA’s historic gun violence in the 90s. We add more guns than there has ever been, 40% of all the guns in the world in the USA, crime goes down - we can’t say adding guns was the reason for a crime drop - but we can say it appears adding more guns did not cause more crime.
Unless you have reason to believe crime would have dropped even more in an alternate universe where a magic wand was waved to remove the hundreds of millions of guns in the USA. But, a statement like that should come with evidence.
1. The number of households that own a gun has actually declined, according to surveys (US law prohibits collection of gun ownership data). We may have added guns, but the number of people + gun availability seem to be declining. If we look at just historic numbers like you say, I would argue that reduced availability of firearms _does_ seem to reduce crime.
2. Despite this decline, the US has a higher rate of gun ownership and availability than other high-income countries, and this correlates with one of the highest rates of homicide amongst those countries. So my naive read of the data would be that an even lower availability of firearms would lead to an even lower homicide rate.
2. Despite this decline, the US has a higher rate of gun ownership and availability than other high-income countries, and this correlates with one of the highest rates of homicide amongst those countries. So my naive read of the data would be that an even lower availability of firearms would lead to an even lower homicide rate.
You clearly don’t understand this topic from the inside so allow me to explain the common trap you are caught in.
You just pointed to bullshit. Not your fault, someone wanted you to think that. But I can promise no one even remotely associated to guns believes this. No. The number of firearm owning households has not decreased. That’s propaganda and you just don’t know any better. I’ve seen it as a competitor and a trainer, new gun owners are making up these records - not as Michael Bloomberg (the single biggest source of gun control money in the world) would have you think. The number of concealed carry permits are at record numbers. The number of training outfits has never been higher. The numbers of protestors for 2A civil rights has never been higher. The only place you’ll see otherwise are antigun outfits with extremely questionable methodology.
The question you should be asking is why do you have your sources lying to you and what else have they lied about?
So right off, you use a lie that is sold to you as comfort food. “Dont worry, it’s just the same few horders trading guns to each other, they aren’t a majority, you are”. Then you use that to make a completely evidencless assumption that less guns equals less crime - when we only have correlation of the opposite.
So… while I really don’t like to apples and oranges… In 1997, Australia banned most all good defensive firearms. They also nearly doubled police per capita. Crime fell! But… in the USA crime fell by a greater amount over the same time period with no ban and only more guns added.
So again; there is absolutely zero proof that less guns equals less crime, especially when faced that more guns hasn’t made more crime.
> So my naive read
Indeed. But the worse part is you don’t want the truth. You are looking for the lie. And going far to find it, why is that?
You just pointed to bullshit. Not your fault, someone wanted you to think that. But I can promise no one even remotely associated to guns believes this. No. The number of firearm owning households has not decreased. That’s propaganda and you just don’t know any better. I’ve seen it as a competitor and a trainer, new gun owners are making up these records - not as Michael Bloomberg (the single biggest source of gun control money in the world) would have you think. The number of concealed carry permits are at record numbers. The number of training outfits has never been higher. The numbers of protestors for 2A civil rights has never been higher. The only place you’ll see otherwise are antigun outfits with extremely questionable methodology.
The question you should be asking is why do you have your sources lying to you and what else have they lied about?
So right off, you use a lie that is sold to you as comfort food. “Dont worry, it’s just the same few horders trading guns to each other, they aren’t a majority, you are”. Then you use that to make a completely evidencless assumption that less guns equals less crime - when we only have correlation of the opposite.
So… while I really don’t like to apples and oranges… In 1997, Australia banned most all good defensive firearms. They also nearly doubled police per capita. Crime fell! But… in the USA crime fell by a greater amount over the same time period with no ban and only more guns added.
So again; there is absolutely zero proof that less guns equals less crime, especially when faced that more guns hasn’t made more crime.
> So my naive read
Indeed. But the worse part is you don’t want the truth. You are looking for the lie. And going far to find it, why is that?
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Maybe not so much job loss but less policing or intervention perhaps as a result of depolicing policies.
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I think it's understandable why the lead-crime hypothesis was/is so popular, because it it's an alternative to the hypothesis that increased incarceration and abortion reduced crime, which, politically, are less popular. It's more politically correct to blame lead poisoning than insufficient policing.
There's at least 16 hypotheses and none of them are that popular. In fact, most people are unlikely to even know that crime has been on a downward trend at all.
The lead hypothesis has not been debunked, and if you read the article in the OP you'll find a number of unanswered questions.
https://www.vox.com/2015/2/13/8032231/crime-drop
The lead hypothesis has not been debunked, and if you read the article in the OP you'll find a number of unanswered questions.
https://www.vox.com/2015/2/13/8032231/crime-drop
Well, crime went down worldwide, whereas abortion and incarceration only went up in the US.
This is exactly why I think environmental, economic, and entertainment factors are the most likely, as they cross political borders.
Everyone is always looking for a political angle, but while everyone is arguing over the efficacy of their team’s favorite crime policies, the answer is probably: give every restless teenager an Xbox and some macaroni and cheese.
Everyone is always looking for a political angle, but while everyone is arguing over the efficacy of their team’s favorite crime policies, the answer is probably: give every restless teenager an Xbox and some macaroni and cheese.
Yeah, cultural changes and access to entertainment might be the simplest answer :)
Though I think I get the argument, it seems quite absurd that we now have arrived at "The absence of evidence of absence is evidence of absence."
It's astonishing to me that any large scale population study can ever prove anything, given how incredibly complex and unique peoples' lives are, and how many confounding factors may play a part at some point in those lives over many years.
Well scientists don’t just rely on them. They would use them as just part of the puzzle. Do we known the mechanism, can we do causal animal experiments and then is there a correlation in humans.
It's insane that publication bias is still a thing that has to be considered in a meta-analysis, that you can't just find any study on a topic ever made.
What is the lead crime hypothesis?
"The lead–crime hypothesis is the association between elevated blood lead levels in children and increased rates of crime, delinquency, and recidivism later in life."[1]
Basically, during the 20th Century, lead were used in a lot of products, including gasoline and paint. To shocking surprise, it turned out that this lead slowly ended up in our environment, and built up in our bodies.
The hypothesis is that because virtually the entire population got lead poisoned, we became more affected by "learning disabilities, decreased I.Q., attention deficit hyperactivity disorder, and problems with impulse control", which again leads to more crime.
Lead was eventually phased out (no thanks to the companies behind the products), and this correlated with a drop in US crime-rates in the early 1990s.
Since then there's been lots of discussion on why the crime rate dropped. The removal of lead from the environment is one (an alternative, but not mutually exclusive, hypothesis is the legalized abortion and crime effect[2]).
[Personally, I've been wondering how this also affects other qualities of the people affected... Would people born before the 1970s have been more intelligent than they are currently? Could this have given us better political leadership, and better secondary and tertiary effects?]
1: https://en.wikipedia.org/wiki/Lead–crime_hypothesis
2: https://en.wikipedia.org/wiki/Legalized_abortion_and_crime_e...
Basically, during the 20th Century, lead were used in a lot of products, including gasoline and paint. To shocking surprise, it turned out that this lead slowly ended up in our environment, and built up in our bodies.
The hypothesis is that because virtually the entire population got lead poisoned, we became more affected by "learning disabilities, decreased I.Q., attention deficit hyperactivity disorder, and problems with impulse control", which again leads to more crime.
Lead was eventually phased out (no thanks to the companies behind the products), and this correlated with a drop in US crime-rates in the early 1990s.
Since then there's been lots of discussion on why the crime rate dropped. The removal of lead from the environment is one (an alternative, but not mutually exclusive, hypothesis is the legalized abortion and crime effect[2]).
[Personally, I've been wondering how this also affects other qualities of the people affected... Would people born before the 1970s have been more intelligent than they are currently? Could this have given us better political leadership, and better secondary and tertiary effects?]
1: https://en.wikipedia.org/wiki/Lead–crime_hypothesis
2: https://en.wikipedia.org/wiki/Legalized_abortion_and_crime_e...
I wonder when someone will see if the rise of home gaming consoles had an effect. A Nintendo effect, if you will.
Why did the most enormous progress happen when this poisoning was widespread?
And it wasn't only once but at least twice: In Ancient Rome lead was also widely used.
The whole idea of "chronic toxicity" is bunk.
It will eventually turn out that lead is essential.
Lead (Pb) the metal.
https://en.m.wikipedia.org/wiki/Lead%E2%80%93crime_hypothesi...
https://en.m.wikipedia.org/wiki/Lead%E2%80%93crime_hypothesi...
Some good article here - but this is my favourite.
https://www.motherjones.com/environment/2016/02/lead-exposur...
https://www.motherjones.com/environment/2016/02/lead-exposur...
By the same author.
Lead causes people to behave aggressively and erratically. The idiom “mad as a hatter” comes from the fact that hatters were around lead a lot for some reason I forgot.
Edit: Ah, apparently it was mercury, not lead. Cute anecdote anyway.
Edit: Ah, apparently it was mercury, not lead. Cute anecdote anyway.
I think you're confusing lead with mercury for the hat-making connection.
why do you need either of those for making a hat?
When felt was made from animal fur, it made it easier and less gross the remove the hair from the hide and soften it.
Previously, urine was used.
Previously, urine was used.
shiny when applied to silk.
Hatters used mercury, not lead.
I knew a person who suffered from lead poisoning (long term occupational exposure).
She wasn't aggressive in any way, just not really "here".
She wasn't aggressive in any way, just not really "here".
Lead is needed for the brain. The person is fully there (in fact more than before) they only stop uncontrollably reacting to everything, and stand straight, instead of being all wobbly.
Mercury and lead poisoning have similar effects.
Poisoning with lead has been linked with sudden rage attacks and homicides. Lead affects the nervous system.
The abstract of the paper describes it.
Isn't this more of a critique of meta-analysis itself? It seems pretty suspect to take a collection of published studies with different populations and different criteria and derive any meaningful meta product from them, especially since we know most research is never actually published.
Would this not just be correlated with areas of poverty? Typically those areas haven't afforded new plumbing in the post-lead world thus far...
The lead here was the lead used in leaded gasoline. It was lead in the air.
Lead poisoning = lower IQ & educational attainment
poor education & lower IQ = locked out of the labor force and more likely to make bad decisions in life
not rocket science.
poor education & lower IQ = locked out of the labor force and more likely to make bad decisions in life
not rocket science.
Yeah, maybe.. but like the blog post says:
> Nor are they the kind of study where you round up a hundred undergraduates and perform an experiment on them.
Do we have good clinical evidence showing: lead = lower IQ? (I'm guessing nobody volunteered for lead poisoning).
Thing is that crime reduction could be cultural, or simple widespread video games :)
(Maybe it's a bit everything, and lead probably isn't the only environmental improvement we've made)
> Nor are they the kind of study where you round up a hundred undergraduates and perform an experiment on them.
Do we have good clinical evidence showing: lead = lower IQ? (I'm guessing nobody volunteered for lead poisoning).
Thing is that crime reduction could be cultural, or simple widespread video games :)
(Maybe it's a bit everything, and lead probably isn't the only environmental improvement we've made)
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Hypothesis before reading: Question in the headline, answer is no.
Confirmed, sigh.
Confirmed, sigh.
Betteridge's Law of Headlines - https://en.wikipedia.org/wiki/Betteridge%27s_law_of_headline...
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Its the cameras.
Freakonomics re-visit the abortion crime link and also talk about lead in 2019 - https://freakonomics.com/podcast/abortion/
The abortion model is simple. Unwanted babies to mothers who don't want them will not grow up well.
We know lots of things target IQ, but the lead model is really complex, it hypothetically reduces impulse control across the entire population and with really tiny amounts in the environment.
When I see it proven in mice not humans I'll be more convinced. (And not large amount of lead in their water bowl)
The abortion model is simple. Unwanted babies to mothers who don't want them will not grow up well.
We know lots of things target IQ, but the lead model is really complex, it hypothetically reduces impulse control across the entire population and with really tiny amounts in the environment.
When I see it proven in mice not humans I'll be more convinced. (And not large amount of lead in their water bowl)
> The lead–crime hypothesis is the association between elevated blood lead levels in children and increased rates of crime, delinquency, and recidivism later in life. (Wikipedia)
(I was interpreting "lead" as related to leadership or being (mis)lead, and was thoroughly confused for the first few paragraphs until I decided to just look it up myself.)