[HN Gopher] Has the lead-crime hypothesis been debunked?
___________________________________________________________________
Has the lead-crime hypothesis been debunked?
Author : monort
Score : 117 points
Date : 2021-07-31 10:32 UTC (12 hours ago)
(HTM) web link (jabberwocking.com)
(TXT) w3m dump (jabberwocking.com)
| lamebitches wrote:
| Covid is a bio-weapon. Fauci is the dealer.
| [deleted]
| _0ffh wrote:
| 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."
| dang wrote:
| 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)
| amadeuspagel wrote:
| 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.
| adenozine wrote:
| 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...
| jsnell wrote:
| > 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.)
| nerdponx wrote:
| > 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.
| codesections wrote:
| > 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.
| geeB wrote:
| > 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.
| pmoriarty wrote:
| _" 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.
| burnished wrote:
| 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.
| pmoriarty wrote:
| 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.
| burnished wrote:
| 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.
| pmoriarty wrote:
| What makes you think that?
|
| I was just throwing an idea out there. I'm not convinced
| of anything.
| Dylan16807 wrote:
| 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.
| pmoriarty wrote:
| 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?
| Gauge_Irrahphe wrote:
| >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.
| pmoriarty wrote:
| _" 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."_
| jsnell wrote:
| That's the "negative effects hacked to positive ones"
| explanation.
| yxhuvud wrote:
| > 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.
| in3d wrote:
| > 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.
| ceejayoz wrote:
| > 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...
| in3d wrote:
| 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.
| ceejayoz wrote:
| That may point to a difference in lockdown policies, safety
| nets (for example: https://www.nytimes.com/2020/07/03/busin
| ess/economy/europe-u...), etc. though.
| in3d wrote:
| 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...
| ceejayoz wrote:
| The link between economic distress and crime is long
| established.
| angry_octet wrote:
| 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".
| SV_BubbleTime wrote:
| > 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"
| jljljl wrote:
| 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
| SV_BubbleTime wrote:
| 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.
| jljljl wrote:
| 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.
| skinkestek wrote:
| 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.
| jljljl wrote:
| 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
| mc32 wrote:
| Maybe not so much job loss but less policing or
| intervention perhaps as a result of depolicing policies.
| [deleted]
| paulpauper wrote:
| 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.
| pasabagi wrote:
| Well, crime went down worldwide, whereas abortion and
| incarceration only went up in the US.
| kube-system wrote:
| 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.
| nwah1 wrote:
| 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
| aaron695 wrote:
| 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)
| tacotacotacos wrote:
| 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?
| 6gvONxR4sf7o wrote:
| 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.
| MontyCarloHall wrote:
| 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.
| dllthomas wrote:
| Though even if it's 1/12, the chance of no negative results
| by chance is still >10%, right?
| jonas21 wrote:
| 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.
| tootahe45 wrote:
| 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.
| andi999 wrote:
| What is the lead crime hypothesis?
| lostlogin wrote:
| Some good article here - but this is my favourite.
|
| https://www.motherjones.com/environment/2016/02/lead-exposur...
| SeanLuke wrote:
| By the same author.
| chrisseaton wrote:
| The abstract of the paper describes it.
| dcminter wrote:
| Lead (Pb) the metal.
|
| https://en.m.wikipedia.org/wiki/Lead%E2%80%93crime_hypothesi...
| toxik wrote:
| 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.
| api wrote:
| Mercury and lead poisoning have similar effects.
| dcminter wrote:
| I think you're confusing lead with mercury for the hat-making
| connection.
| nytgop77 wrote:
| why do you need either of those for making a hat?
| Spooky23 wrote:
| 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.
| lostlogin wrote:
| Yikes. Knowing what we know now, is mercury the worse
| option?
| redis_mlc wrote:
| Urine is cleaned by the kidneys. Surgeons drain the
| urethra directly into the body during kidney surgery
| because it's antiseptic. So urine is not gross or dirty.
|
| (Some idiotic US town a few years ago considered draining
| their large water reservoir because a teen urinated from
| the bank. Nevermind that fish and birds do that all day
| long. But the residents had no common sense.)
| Spooky23 wrote:
| It depends. Urine is not pleasant, but is usually safe to
| work with. I'd rather smell than suffer brain damage. :)
| snowmanbob wrote:
| shiny when applied to silk.
| cafard wrote:
| Hatters used mercury, not lead.
| Tade0 wrote:
| I knew a person who suffered from lead poisoning (long term
| occupational exposure).
|
| She wasn't aggressive in any way, just not really "here".
| arbitrage wrote:
| Did she ever get better?
| Tade0 wrote:
| Unfortunately not. Or, any chance for that was lost when
| she had a stroke.
| Gauge_Irrahphe wrote:
| 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.
| veqz wrote:
| "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...
| cptnapalm wrote:
| I wonder when someone will see if the rise of home gaming
| consoles had an effect. A Nintendo effect, if you will.
| Gauge_Irrahphe wrote:
| 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.
| Retric wrote:
| Hypothesis before reading: Question in the headline, answer is
| no.
|
| Confirmed, sigh.
| philjohn wrote:
| Betteridge's Law of Headlines -
| https://en.wikipedia.org/wiki/Betteridge%27s_law_of_headline...
| [deleted]
| gttalbot wrote:
| 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.
| corty wrote:
| 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.
| shreyshnaccount wrote:
| they still use that? even when it's a known neurotoxin?
| NickNameNick wrote:
| 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.
| shreyshnaccount wrote:
| makes sense thanks for sharing
| [deleted]
| anonuser123456 wrote:
| Your impression is correct. The mercury is quite
| chemically bound.
|
| The caveat is that when it is removed, it may not be so
| bound.
| foobiekr wrote:
| The alternative to amalgam is commonly composite fillings
| which are BPA.
| corty wrote:
| There is still gold and ceramics. But both are of course
| more expensive.
| jessaustin wrote:
| 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.
| astura wrote:
| Another downside to amalgam fillings is that they require
| more drilling (and thus more tooth removal) than composite
| fillings.
| aidenn0 wrote:
| 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.
| jessaustin wrote:
| In practice, that's a way to reduce claims rather than a
| way to encourage a particular filling material.
| astura wrote:
| I think this is absolutely correct because very few
| dental offices still perform amalgam fillings at all.
| aidenn0 wrote:
| I have amalgam fillings from about 2010 because the
| dentist didn't offer me composite. My new dentist does
| only do composite.
| elktea wrote:
| 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.
| Inhibit wrote:
| 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!
| soared wrote:
| Lead paint is not an immediate issue unless it is flaking or
| someone does something to it.
| kijin wrote:
| 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.
| gbtw wrote:
| Also avgas still mostly has lead in it:
| https://en.wikipedia.org/wiki/Avgas
| jabl wrote:
| 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
| kube-system wrote:
| 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.
| jabl wrote:
| > 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.
| kube-system wrote:
| 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.
| [deleted]
| coding123 wrote:
| Its the cameras.
| 100011 wrote:
| In US, roughly 13% of the population (blacks) commit roughly 56%
| of homicides. That is a per capita murder rate 8.2 times higher
| than the non-black murder rate (2019 FBI statistics). The murder
| rate among the Hispanics, who are almost as poor as blacks, is
| less than half that among blacks.
|
| But it's the lead I'm sure, lol.
| fouc wrote:
| > 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.
| HWR_14 wrote:
| 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.
| corty wrote:
| 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".
| ectopod wrote:
| Don't forget outright fraud.
|
| https://news.ycombinator.com/item?id=27884233
| paulpauper wrote:
| 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.
| hristov wrote:
| 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.
| CalRobert wrote:
| Maybe because it suggests our elites have brain damage making
| them more likely to have poor impulse control.
| gus_massa wrote:
| > _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
| S. See again https://en.wikipedia.org/wiki/Normal_distribution
|
| In a real word you expect to see something somewhat similar to
| an inverted S. But the graphic shows only a L, Where is the top
| horizontal part of the inverted S???
|
| 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 S in the
| graphic is close to 0, too close to 0. You can see that the
| lower tic of the inverted S 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 S 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 S 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 S, both in the positive part.)
| jonnycomputer wrote:
| 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.
| mabbo wrote:
| 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/
| jhbadger wrote:
| 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.
| Hammershaft wrote:
| I think many people are uncomfortable with the idea that a
| chemical or unknown environmental change can cause such
| marked changes in human behavior.
| michaelmrose wrote:
| To be even more accurate the older folks are uncomfortable
| with provable allegations that they are brain damaged.
| Gibbon1 wrote:
| 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.
| jonnycomputer wrote:
| 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/10.1101/2021.06.11.212586
| 90v...
| rsgrn wrote:
| 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.
| Gibbon1 wrote:
| 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?
| jeffbee wrote:
| 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.
| Barrin92 wrote:
| >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.
| bjourne wrote:
| 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?
| gjhh244 wrote:
| 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.
| Gauge_Irrahphe wrote:
| That's just wishful thinking. The costs on health could be
| massive if lead is essential. (and it very likely is)
| jl6 wrote:
| 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.
| unparagoned wrote:
| 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.
| lucb1e wrote:
| Since it's never explained what this is about, before you read
| the article you might want to know:
|
| > 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.)
| NikolaNovak wrote:
| I on the other hand assumed it was about initial/smaller crime
| "leading" into bigger/continues crimes.
|
| I heart English Language!
| jeffbee wrote:
| 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.
| [deleted]
| noxer wrote:
| > 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.
| jeffbee wrote:
| 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.
| spoonjim wrote:
| 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.
| MontyCarloHall wrote:
| 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.
| jeffbee wrote:
| One of the studies I'm thinking of relies on the boundary
| effect, where children who tested with 100ug/dl of lead
| in their blood were all treated and those with 99.99ug/dl
| were not, and this threshold (I'm not sure exactly what
| it was) is way too high.
| [deleted]
| monort wrote:
| 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/
| jeffbee wrote:
| 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
| birdyrooster wrote:
| 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.
| jvanderbot wrote:
| 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.
| jeffbee wrote:
| 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.
| mandevil wrote:
| 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.)
| Kranar wrote:
| In the U.S., yes. In the rest of the developed world, no.
| mmvhncx wrote:
| 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
| dv_dt wrote:
| 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.
| karmakaze wrote:
| 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.
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