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Crime Reduction Linked To Lead-Free Gasoline
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."
So does this mean with all the lead paint we are seeing in toys now, we will see another spike in violent behavior.
...Freakonomics correlated the drop in crime rates with the legalization of abortion. Which sounds more sound of a theory to you?
Levitt's book is cited in the first paragraph of the paper, which is very interesting, but rather hard to understand on a (very) brief reading. Essentially, she says that lead contributes 56% to the drop in crime, while the availability of abortions contributes 29%.
Reality is defined by the maddest person in the room
"It couldn't be related to the fact that we have more criminals than ever cooling their heels in prison?"
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.
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BMO
Roe v. Wade. Reduction in unwanted kids results in less criminals. More abortions for all!
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
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. It's actually just a problem with their survey method. They used to do a catch-release system to estimate the number of pirates, and identify them by markings on their earrings, patches, hooks, peglegs, etc. They also used a certain set of criteria (apart from the basic one of piracy) to identify pirates, and as the surveys have continued through the years they've failed to update their processes and criteria for changes in pirate fashions. (Basically, that pirates have come to favor other beverages apart from rum, the gradual improvements in prosthetics and the improvements in naval safety and changes in naval warfare which have reduced the incidence of dismemberment among pirates... the drastic changes in pirate lingo and their favored methods of doing business...)
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.
Bow-ties are cool.
"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.
These statistical correlations are a complete crock. There are a million things that have changed over the last few years that could also be attributed.
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.)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
China is taking care of this problem with their usual efficiency, so stop giving them a hard time.
Reading the article, they already control for abortion, the average crime rate per year, the average crime rate for individual states, and even the effects of people moving from one state to another. The lead level measurements were finer grained than "lead existed before this date, then, everyone stopped using it"- they included state-by-state, year-by-year measurements in their lead data, adjusting for population density (as a surrogate for traffic density).
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.