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Crime Reduction Linked To Lead-Free Gasoline
Posted by
kdawson
on Tue Oct 23, 2007 02:55 PM
from the getting-the-lead-out dept.
from the getting-the-lead-out dept.
Hugh Pickens writes "Even low levels of lead can cause brain damage, increasing the likelihood of behavioral and cognitive traits such as impulsivity, aggressiveness, and low IQ that are strongly linked with criminal behavior. The NYTimes has a story on how the phasing out of leaded gasoline starting with the Clean Air Act in 1973 may have led to a 56% drop in violent crime in the US in the 1990s. An economics professor at Amherst College, Jessica Wolpaw Reyes, discovered the connection and wrote a paper comparing the reduction of lead from gasoline between states (PDF) and the reduction of violent crime. She constructed a table linking crime rates in every state to childhood lead exposure in that state 20 or 30 years earlier. If lead poisoning is a factor in the development of criminal behavior, then countries that didn't switch to unleaded fuel until the 1980s, like Britain and Australia, should soon see a dip in crime as the last lead-damaged children outgrow their most violent years."
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Lead (Score:5, Interesting)
Re:Lead (Score:5, Funny)
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Oh come on (Score:5, Funny)
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Re:Lead (Score:5, Insightful)
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Re:Lead (Score:5, Informative)
I briefly read the study and she does take age into account. She uses crime rates (not absolute numbers) and finds a correlation between lead exposure in youth and crime rates at age 22 (peak crime age) using FBI data. The rates for those who grew up before leaded gas exposure were flat and rise in synch with leaded gas usage/exposure. She also points out that rates dropped the most in those states that had the greatest lead exposures.
I'd cut and paste the text but Adobe isn't cooperating.
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correlation, causation and all that? (Score:5, Insightful)
Of course I haven't read the paper
ARRRR! (Score:5, Insightful)
Of course I haven't read the paper
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Re:ARRRR! (Score:5, Funny)
Of course the more interesting correlation is a group that prides themselves on being enlightened and rational above all else, like the fans of the FSM would be so out of touch that they didn't know that there where still pirates on the high seas and that it is a real problem for shipping.
As a result, the most recent surveys only turned up a very small number of pirates: Captain Hook (who hasn't aged for a considerable period of time), the Dread Pirate Roberts (whose centuries-long career defies all explanation - the survey teams are still trying to find an explanation), and a handful of others...
Of course, the disciples of the FSM have not overlooked these new facts. For a while, there has been a certain amount of doubt as to whether the results of this study really indicated that a decline in the number of pirates was the cause of global warming. Some said there could be other explanations, while others insisted that the whole situation merited further study and that it was too soon to draw any conclusions at all. Now, though, I think we can safely say, with a moderate level of cautious near-certainty, that the decline of piracy might not actually be entirely responsible for the increase in global temperature. There may be other factors, too.
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Re:correlation, causation and all that? (Score:5, Informative)
"Lead has also been associated directly with delinquent, criminal, and aggressive behavior. Denno [1990] finds that lead poisoning is the most significant predictor of disciplinary problems and one of the most significant predictors of delinquency, adult criminality, and the number and severity of offenses. Needleman et al. [1996] find a significant relationship between the amount of lead in bone (a good measure of past exposure) and antisocial, delinquent, and aggressive behaviors. Dietrich et al. [2001] followed a cohort of 195 inner-city youths from birth through adolescence, and found a clear linear relationship between childhood blood lead levels and the number of delinquent acts. In addition, Needleman et al [2002] showed that adjudicated delinquents were four times as likely to have high lead levels than non-delinquents, and several studies have shown that violent criminals exhibit higher levels of lead in their bodies than nonviolent criminals or the general population.25"
It seems to me that this environmental hypothesis is testable (and confirmed) far beyond what is attainable for most theories in the social sciences.
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That's funny... (Score:5, Interesting)
RTFP! (Score:5, Informative)
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Re:RTFP! (Score:5, Insightful)
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The other way round... (Score:5, Funny)
Correlation and causation (Score:5, Insightful)
This was a sophisticated analysis; I wouldn't call it, as some commenters above have, "junk science". It would be surprising for their observed relation to hold, but their interpretation be incorrect. It would be interesting for someone to really come up with an alternative explanation of this paper's observations.
As a side note, I'm pretty sure that by now most lay people, and everyone reading this forum, is aware that correlation does not imply causation. And I'd be willing to guess that the vast majority of scientists have been aware of this elementary statistical fact for some time. It's likely that scientists take many potential influences into account before submitting for publication. So can we please exercise some restraint in the future and actually read the article before denouncing it as "junk science" because, as everyone knows, correlation is not causation? I am emphatically not asking people to take what the researcher says on faith, but if you decry the article without reading it, then your words are essentially noise.
Re:Prison Population (Score:5, Insightful)
TFA says that _violent_ crime is down. If there are fewer violent offenders, then how does that explain why the prisons are overfilled? The prison population exploded because we're putting more _nonviolent_ offenders in jail.
Bad troll, no cookie. Try better next time.
--
BMO
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Re:Prison Population (Score:5, Informative)
Since 1992, approximately six million Americans have been arrested on marijuana charges, a greater number than the entire populations of Alaska, Delaware, the District of Columbia, Montana, North Dakota, South Dakota, Vermont and Wyoming combined. Annual marijuana arrests have more than doubled in that time.
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Re:Prison Population (Score:5, Insightful)
From where do you get your stats, besides your arse?
"But more than legalization, I support democracy."
Then you should support the ability of states to decide on their own instead of the use of the commerce clause by the federal government to beat up states that don't toe the line, shouldn't you?
Funny about your use of the word "democracy" there when you actually support federalism. Troll much?
--
BMO
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McStats: Funny, not Biotech! (Score:5, Funny)
Personally, I think the most likely cause is one of:
* Reduction in the use of slide rules. With calculators it's easier to get a job as a clerk.
* Increase in CPU speed. Too much time playing games == less time being bad.
* Global warming. It's getting too hot to commit crime.
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Re:McStats: Funny, not Biotech! (Score:5, Insightful)
If you want to bash their study, fine, but at least RTFP, not just the summary on slashdot.
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What else happened in 1973? (Score:5, Interesting)
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Re:What else happened in 1973? (Score:5, Funny)
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Re:McStats: Funny, not Biotech! (Score:5, Insightful)
* Slide Rule and CPUs: This would show a marked drop which could be mapped by time and income bracket (as these would be the two factors mandating uptake), and not geographic region by state.
* Global warming: This would show a marked drop which could be mapped by latitude, proximity to large bodies of water, and time, as these would all be mitigating/exaggerating factors in the relevant changes.
Find correlations with these factors, and maybe one of your theories can be tested. (and actually, global warming might be a good one - too much heat means more agitated people at lower latitudes, more happy people at higher latitudes, if we take the theory that crime to be inversely proportionate to happiness).
Occams razor people - this correlation works because it is one of the simpler explanations that fits what happened. Additionally, a testable prediction has been made from it - in 10-15 years, the theory will be tested.
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One that does survive regression analysis: (Score:5, Informative)
One that was done piecemeal (so regression analysis could be performed) and which produced a strong signal under such analysis: Allowing law-abiding citizens to carry concealed weapons for self-protection against criminals. This drastically lowers the overall violent crime and injury/death rates (even if you DO count any crooks shot in self-defense as a "victim").
Interestingly, while many thought it might produce a short bloodbath (until criminals got the message that some of their victims might be armed), that didn't happen. Instead the violent crime rate just dropped, as criminals moved to less-armed areas, switched from muggings, armed robberies, carjackings, "hot" (occupied-dwelling) burglaries, to things like burglarizing UNoccupied homes and stores, or just found legal work. Rapes dropped like a rock, too (though they went up somewhat in nearby areas that hadn't yet liberalized their own laws.)
Turns out the crooks weren't SO stupid that they couldn't see the writing on that wall. And even those who didn't get the message right away usually weren't dumb enough to keep attacking, rather than run away, when they found themselves looking at the wrong end of a pistol.
(When Florida changed to non-discretionary CCW (i.e. the license has to be granted if the applicant jumps through the correct hoops and doesn't have a criminal record), one gang switched to hitting tourist in rental cars, on the assumption they'd be unarmed - both by airport regs and lack of a permit. Florida fixed that by removing the requirement that rental cars have distinctive markings/licenses and by issuing concealed carry permits to tourists. B-) Interestingly, even during the peak of the rob-the-Florida-tourists boom a tourist had less chance of being robbed in Florida than in California.)
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Re:Yet again it bears repeating... (Score:5, Insightful)
Correlation does not imply causation. While the correlation may be very strong, causation cannot be assumed without ruling out many other potential contributing factors.
How many people have to post this needless gibberish over and over again? Is it some sort of karma whoring?
I mean, the effing SUMMARY got it 100% right:
"Even low levels of lead can cause brain damage, increasing the likelihood of behavioral and cognitive traits such as impulsivity, aggressiveness, and low IQ that are strongly linked with criminal behavior."
We know lead causes brain damage, and we know brain damage can lead to agressiveness, violence, etc.
"The NYTimes has a story on how the phasing out of leaded gasoline starting with the Clean Air Act in 1973 may have led to a 56% drop in violent crime in the US in the 1990s."
Key words: MAY HAVE LED TO. Its a hypothesis. Good.
They aren't asserting causation. They are noting a correlation, and using reasoning to form a hypothesis. So far so good.
An economics professor at Amherst College, Jessica Wolpaw Reyes, discovered the connection and wrote a paper comparing the reduction of lead from gasoline between states (PDF) and the reduction of violent crime. She constructed a table linking crime rates in every state to childhood lead exposure in that state 20 or 30 years earlier.
Documenting the correlation. Even better, its not anecdotal. We're collecting real empirical measurable evidence.
If lead poisoning is a factor in the development of criminal behavior, then countries that didn't switch to unleaded fuel until the 1980s, like Britain and Australia, should soon see a dip in crime as the last lead-damaged children outgrow their most violent years."
A useful prediction? Can it be? Holy shit. Its the full on scientfic method in action. Observe World, Formulate Hypothesis, Test Hypothesis.
I grant that is not the best possible test of the hypothesis, because its not a closed experiment, and its not really repeatable, and a lot of unknowns can get in the way, but we take what we can get. Human-centric sciences like medicine and psychology, or sciences like astrophysics or evolution don't have the luxury of perfect experiments - we can't raise humans in isolated bubbles, nor send a selection of stars into identicale blackholes nor watch a million isolated generations of people --
All we can do in these cases is come up with hypotheses and models, make predictions based on those models to see if we can find examples / counter examples in the observable world.
Overall, its good science here. If the dip in crime occurs where they occur when they predict it, it obviously it won't prove or disprove the hypothesis but it will add significantly to the body of evidence that supports it. If it doesn't occur then we'll have to refine or discard the hypothesis. If ultimately the hypothesis is junk it'll eventually get tossed out. Science is full of wrong hypothesises, but they are the best we have at any given time... that's how it works.
So what exactly do you object to here? That you felt the need to drone about the difference between causation and correlation. It seems everybody involved already got that memo.
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Lead levels in rome were already looked at. (Score:5, Informative)
They already were.
Body loads of lead were very high in the later periods - especially among the upper, decision-making, classes. To the point that lead was believed to have been the major cause of a lack of fertility among the upper classes and the decline of those families.
Turns out it wasn't the lead plumbing - where the lead pretty much stayed in the pipes. They had figured out that if you put a lead liner in wine bottles the wine stayed sweet as it aged, rather than turning sour. But that's not because it DOESN'T turn to vinegar - instead the vinegar (acetic acid) reacts with the lead to form lead acetate - which is so sweet it's also called "sugar of lead". And it's REALLY well absorbed by the body.
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