The main cause of the raise and fall of crime in the 20th century was lead

[Barrister]

correlation causation?

Did you read the article?

It spends a lot of time discussing that problem.

[OttoVonBismarck]

I dunno.  I'm definitely keen on mechanistic explanations as to why people have X problem, but violent crime both on an individual and organized level certainly predates large-scale lead pollution (e.g., brigandry).  It wasn't lead that kept brigands and pirates in the field or on the high seas, nor lead that prompted raiders to destroy whole societies.  According to a few graphs I've read (provenance hard to determine, but this is The Internet) you also had very high, nearly 1970s/80s style homicide rates following the turn of the century and prior to the 40s, which I guess was a pre-lead era, or at least an era before serious lead contamination via internal combustion exhaust.

My own pet theoy as to nosediving violent crime rates involves sending so many 18-22 year old men to college instead of leaving them to their own devices.  Economically, it's at best money half-wasted, but it does keep the demographic most prone to violent crime fed, sheltered, and quasi-gainfully occupied until they drift out of the demographic.  The college experience itself also probably mellows people, lets any prospective criminal skills wither on the vine (just like job skills!), and gives them something, or at least the illusion of something, to lose.

Yeah, yeah, I know I've got an axe to grind against schools, and I'm being a little tongue in cheek, but the collapse in crime rates does roughly coincide with widespread availability of college for young men beginning in the late eighties and early nineties, continuing to nearly-universal availability today.

Interestingly, the other collapse in homicide rates recorded--the 40s and 50s--also coincided with young men being co-opted by the government, albeit there in the form of mass conscription.  Indeed, while there is a steep rise occurring during the war, serious 9 or 10/100,000 homicide rates don't return until after Vietnam.

I'm too lazy to do the legwork and find it, but a few years ago I read one of the few studies I've personally seen on pre-20th century crime rates. Prior to about 1850, violent crime rates were generally quite high per 100,000, in both the United States and Western Europe. They were also quite similar to one another between those two entities. After 1850, violent crime has been on a long term downward trend, with fluctuations, but the downward trend in Western Europe started to drop off much faster than the one in the United States. I found it interesting because it shows that at least from a numbers perspective, what many people often assume, that the United States one day suddenly became more violent out of sync with the rest of the West isn't accurate. Instead, we all started very violent and Western Europe got less violent at a much faster and higher rate than the United States. This report also mostly showed some of the  big "crime problems" of the 20th century as just relatively minor bumps in the long term curve of downward crime rates.

I guess probably because of the abundance of data availability, many people think violent crime statistics start in the mid-20th century, 1930s at the earliest. If that's all you look at it tells a story of rising American crime that has fallen off in the 1990s-Present. But if you look at more historical data it shows it's really just a generally downward trend overall and even the spike we had in 60-90s is just a minor wave on the overall downward moving trend.

[Viking]

correlation causation?

Man this is really starting to be overused.  Sometimes I get the impression people think correlation *disproves* causation.

Not it doesn't disprove anything. It is a demand for a demonstration of the causal link and ruling out some other cause for both phenomena which has not been mentioned.

e.g. the pirates vs. global warming graph, or the link between denim jeans and obesity, or the link between railroads and black suits etc.etc.

The problem with the lead phenomena is that there is no plausible cause identified. Yes there is less lead in our bodies but you still need to show how that relates to violent or criminal behavior. As many people have shown many other correlates match, abortion rates, policing policy etc.

[Admiral Yi]

The problem with the lead phenomena is that there is no plausible cause identified.

Sure there is.  The effect of lead on development of white matter and the pre-frontal cortex.

[dps]

correlation causation?

Man this is really starting to be overused.  Sometimes I get the impression people think correlation *disproves* causation.

Not it doesn't disprove anything. It is a demand for a demonstration of the causal link and ruling out some other cause for both phenomena which has not been mentioned.

e.g. the pirates vs. global warming graph, or the link between denim jeans and obesity, or the link between railroads and black suits etc.etc.

The problem with the lead phenomena is that there is no plausible cause identified. Yes there is less lead in our bodies but you still need to show how that relates to violent or criminal behavior. As many people have shown many other correlates match, abortion rates, policing policy etc.

As BB asked, did you read the article?  Because this was addressed:

This has been a topic of intense study because of the growing body of research linking lead exposure in small children with a whole raft of complications later in life, including lower IQ, hyperactivity, behavioral problems, and learning disabilities.

Mind, I still wouldn't call this proof, but it certainly suggests a causal link

[mongers]

The problem with the lead phenomena is that there is no plausible cause identified.

Sure there is.  The effect of lead on development of white matter and the pre-frontal cortex.

I'm going with Yi here, the effects of lead pollution on humans is well understood, hence the various pieces of legislation across the world.

If there is any casual truth in the article, thanks Tim, then that's a nice added benefit.

Of course, I'm of the opinion that it's bound to be a lot more complicated than just the one factor in lead, but it could be significant and this study is a good starting point for further research. 

[Admiral Yi]

As BB asked, did you read the article?  Because this was addressed:

This has been a topic of intense study because of the growing body of research linking lead exposure in small children with a whole raft of complications later in life, including lower IQ, hyperactivity, behavioral problems, and learning disabilities.

Mind, I still wouldn't call this proof, but it certainly suggests a causal link

Actually, those are just more examples of correlation. What you need on top of that is a (plausible) biochemical mechanism. 

[crazy canuck]

correlation causation?

BTW, the best refutation of the lead and christianity theories of roman decline is Byzantium itself.

How so? Byzantium continued the decline.

Byzantium was in decline for longer than most civilizations last. The reason that Byzantium refutes it is because they used the same plumbing and were more christian than the west.

Byzantuim and the West had, of course, different brands of Christianity.  The theory regarding Christianity contributing to the decline relates to the differences between the Roman Church and the Greek Church. The theory goes that when the Roman Church became dominant in Western Europe, especially through the efforts of Ambrosius, the critical thought of the Greek tradition was replaced by the unquestioning obedience of the Roman tradition.

That of course is putting it very simplistically but it will suffice to make the point that your refutation of the theory does not address the argument.  Rather the continuation of Byzantium supports the theory since Byzantium continued on in the Greek tradition.

Executive summary:  There are a number of points that can be made to refute the theory but yours is not one of them.

[dps]

As BB asked, did you read the article?  Because this was addressed:

This has been a topic of intense study because of the growing body of research linking lead exposure in small children with a whole raft of complications later in life, including lower IQ, hyperactivity, behavioral problems, and learning disabilities.

Mind, I still wouldn't call this proof, but it certainly suggests a causal link

Actually, those are just more examples of correlation. What you need on top of that is a (plausible) biochemical mechanism. 

Presumably, if one reads the studies in question, then one finds the mechanism addressed there.

[Viking]

Mind, I still wouldn't call this proof, but it certainly suggests a causal link

Which is why I thought it prudent to remind tim of the fact that the causal link still is missing. The title says

The main cause of the raise and fall of crime in the 20th century was lead

So far the best argument has been "I can see how lead might be a significant factor....". Apart from the obvious correlation/causation issue my first grip would be with the assertion that there was a rise in the crime rate during the 20th century.

http://www.ted.com/talks/steven_pinker_on_the_myth_of_violence.html

[viper37]

As for the article, it is certainly interesting, but I suspect that no one factor is fully explanatory; for example, unleaded gas was used all over NA but crime rates varied a lot from place to place. It is certainly possible that lead made thinks worse overall than they would otherwise have been, though.

actually, Canada & US crime rates move in the same direction.  And there's more crimes in cities (more vehicles) than in small places.  Cows&trees don't kill people.  Well, the non stupid ones anyway.

[mongers]

As for the article, it is certainly interesting, but I suspect that no one factor is fully explanatory; for example, unleaded gas was used all over NA but crime rates varied a lot from place to place. It is certainly possible that lead made thinks worse overall than they would otherwise have been, though.

actually, Canada & US crime rates move in the same direction.  And there's more crimes in cities (more vehicles) than in small places.  Cows&trees don't kill people.  Well, the non stupid ones anyway.

I think it's less about cars killing people, but to do with taking several thousand/tens of thousands of dollars worth of property,making it moveable and placing it in public spaces.

Just that along generates all sorts of stupid shit, you only have to look to the 'evidence' on 'Judge Judy', every 2nd dispute seems to be about someone doing something to someone elses car,or borrow money from a 'friend' to buy/do up a car.   

[crazy canuck]

As for the article, it is certainly interesting, but I suspect that no one factor is fully explanatory; for example, unleaded gas was used all over NA but crime rates varied a lot from place to place. It is certainly possible that lead made thinks worse overall than they would otherwise have been, though.

actually, Canada & US crime rates move in the same direction.  And there's more crimes in cities (more vehicles) than in small places.  Cows&trees don't kill people.  Well, the non stupid ones anyway.

I have never met a stupid tree.

[Barrister]

As for the article, it is certainly interesting, but I suspect that no one factor is fully explanatory; for example, unleaded gas was used all over NA but crime rates varied a lot from place to place. It is certainly possible that lead made thinks worse overall than they would otherwise have been, though.

actually, Canada & US crime rates move in the same direction.  And there's more crimes in cities (more vehicles) than in small places.  Cows&trees don't kill people.  Well, the non stupid ones anyway.

I dispute that notion.  Canada's most violent communities are all small and remote.

[Valmy]

As for the article, it is certainly interesting, but I suspect that no one factor is fully explanatory; for example, unleaded gas was used all over NA but crime rates varied a lot from place to place. It is certainly possible that lead made thinks worse overall than they would otherwise have been, though.

actually, Canada & US crime rates move in the same direction.  And there's more crimes in cities (more vehicles) than in small places.  Cows&trees don't kill people.  Well, the non stupid ones anyway.

I have never met a stupid tree.

It does, however, explain my extreme fear of stupid cows.