Lead and Violent Crime

I have heard of this alleged link in the past.

Mother Jones article here.

http://www.motherjones.com/kevin-dru...

IMAGE(http://www.motherjones.com/files/Lead_Crime_325.gif)

That chart is just one snippet in what I think is a convincing case lead is a major culprit in crime.

IMAGE(http://www.venganza.org/images/PiratesVsTemp.png)

Correlation does not equal causality. Still, an interesting thought.

It's more than an interesting thought, and more than a correlation. This effects of lead in general have been known for decades. Its reduction in the environment is certainly a causative factor behind the lower violent crime levels that are being experienced, and likely a major one.

There is not even a correlation they are using magic numbers (23 years) to show one. The EPA put on schedule to phase out lead entirely as a fuel additive in 1973, it was completely phased out in 1996.

http://www.pbs.org/newshour/indepth_...

In the early 90's less than 1 percent of gas sold had lead. And in the 70's and 80's lead levels in human bodies fell by over 50 percent but crime continued to rise in the following decades. These were our highest crime decades, peaking in the early 90's.

This link has been shown before. But every serious criminologist that I knew of also noted that the highest concentrations of lead in the area were in poor, urban, industrial areas-areas with a lot of smelting, mining, emissions, etc. Poor areas have more crime.

You can more directly track the US incarceration rate with the decline in crime, longer sentences, 3 strikes, laws. Our incarceration rate peaked in the mid 90's, at precisely the same time the downward trend in crime began.

For all the folks scoffing at this, I'd encourage you to take a look at the full article:

http://www.motherjones.com/environment/2013/01/lead-crime-link-gasoline

The methodology of these studies is damn convincing.

If childhood lead exposure really did produce criminal behavior in adults, you'd expect that in states where consumption of leaded gasoline declined slowly, crime would decline slowly too. Conversely, in states where it declined quickly, crime would decline quickly. And that's exactly what she found.
Nevin collected lead data and crime data for Australia and found a close match. Ditto for Canada. And Great Britain and Finland and France and Italy and New Zealand and West Germany. Every time, the two curves fit each other astonishingly well. When I spoke to Nevin about this, I asked him if he had ever found a country that didn't fit the theory. "No," he replied. "Not one."

It is the conclusion I am skeptical about. Drop in lead=drop in crime 23 years later. Not the least being, why 23? I have to figure it is either matching the charts, or seeking to define 23 years as a generation over time. But a mother's age at first birth has been increasing, it was at 20 in the 60's, 21 in 1970, 23 in 1980, 24 in 1990, and is up to 27 now. However, the constant trend is that at risk populations, urban minorities are running ahead of the pack in teenaged births. This is further compounded with age demographics of violent offenders. The average age of a murder arrestee was under 17 in the 80's, was at 18 and the 90's with a hugely disproportional amount of violent crime committed by teenaged boys in this time; peak in the mid 90's, meaning those offenders were born when Lead was on the heaviest decline-the mid and late 70's.

Perhaps line up the CDC's numbers on birth, with the crime rate, in particular among demographics over-represented among the prison population.

http://www.cdc.gov/nchs/data/nvsr/nv...

It's 23 years because lead exposure as a toddler affects the brain in ways that lead to criminal behavior as an adult. Mother's age at first birth has nothing to do with it.

Really, read it. This is as convincing as social science research gets.

King gorilla - I made a mistake. There are 2 articles. Read the one jonstock linked to.

How I see it, both crime and lead are more prevalent in poor communities. I don't think removing one will prevent the other.

LobsterMobster wrote:

How I see it, both crime and lead are more prevalent in poor communities. I don't think removing one will prevent the other.

crime rates have down country by country, state by state, and city by city in this same correlation.

You see the same correlation with teenage pregnancies.

I did, and it reads like the link between warm weather and crime.

But in the 80's and 90's the most violent offenders were teenagers-the crime rate among those 17-20 was ridiculous. The most violent generation were the people born after lead levels began declining. More to the point, the most violent offenders had not reached maturity in their brains. Even today the largest criminal demographics are those 18-24, who should have the lowest exposures to lead but immature brains.

The growth trend in the last decade is an increase in the crime rate among those 25-34. These are the people who were toddlers as lead was declining sharply, with mature brains but are the only group today whose crime rate is significantly rising. Odds are in another 10 years the 18-24 demo and the 25-34 will be the same.

The hypothesis is that lead exposure as a toddler, leads to more criminal behavior as an adult. I do not see that meted out in the crime date from the 60's through today, especially considering that in the darkest decade the mid 80's to the early 90's, the majority of violent offenders were 14-24. There is a huge drop off in the violent crime rate in that same ere when you get to the age of 25 and over. Based on the hypothesis, the exact reverse should be true, the violent criminals would be concentrated among those born prior to 1973.

Fun DOJ Moving Picture.

IMAGE(http://bjs.ojp.usdoj.gov/content/homicide/ortsanm.gif)

Like I said, I just to not see the hypothesis of lead exposure as a kid plus 23 years meted out when you consider the fact that the largest pockets of violent offenders in the late 80's and 90's were 14-17, 18-24 (the peak is 19-21) and that the crime rates for those 25 and older dropped off fast. And in the modern day, the only criminal population rising are those 25-34(those born as lead was starkly declining).

I think lead can be a good indicator, much like the link between the number of books in a home and a child's likelihood of engaging in criminal acts, or mother's age and education level at the time of first birth.

It also is not getting into any explanation of male vs female demographics in criminality. Every girl in the 50's, 60's, 70's was exposed to the same amount of lead. The same for minorities vs whites in that same era.

KingGorilla wrote:

It also is not getting into any explanation of male vs female demographics in criminality. Every girl in the 50's, 60's, 70's was exposed to the same amount of lead.

A second study found that high exposure to lead during childhood was linked to a permanent loss of gray matter in the prefrontal cortex—a part of the brain associated with aggression control as well as what psychologists call "executive functions": emotional regulation, impulse control, attention, verbal reasoning, and mental flexibility. One way to understand this, says Kim Cecil, another member of the Cincinnati team, is that lead affects precisely the areas of the brain "that make us most human."

So lead is a double whammy: It impairs specific parts of the brain responsible for executive functions and it impairs the communication channels between these parts of the brain. For children like the ones in the Cincinnati study, who were mostly inner-city kids with plenty of strikes against them already, lead exposure was, in Cecil's words, an "additional kick in the gut." And one more thing: Although both sexes are affected by lead, the neurological impact turns out to be greater among boys than girls.

The same for minorities vs whites in that same era.

Like many good theories, the gasoline lead hypothesis helps explain some things we might not have realized even needed explaining. For example, murder rates have always been higher in big cities than in towns and small cities. We're so used to this that it seems unsurprising, but Nevin points out that it might actually have a surprising explanation—because big cities have lots of cars in a small area, they also had high densities of atmospheric lead during the postwar era. But as lead levels in gasoline decreased, the differences between big and small cities largely went away. And guess what? The difference in murder rates went away too. Today, homicide rates are similar in cities of all sizes. It may be that violent crime isn't an inevitable consequence of being a big city after all.

Remember that the era of the 50's, 60's, 70's were also the era of White Flight.

And the fact that the key criminal offenders and most violent are those born and raised well after lead levels began starkly declining; that our rising demographic of violent offenders in the modern era was born after 1979; the dip in crime from 79-85 before the sharp increase? That is the big darn issue I have with the conclusion.

By the hypothesis, peak lead in the 50's and 60's before the large white flight in the late 60's and early 70's is to blame. It is irrelevant, based on the hypothesis, because it is exposure ages birth to 3 or 4 that is important to factor in.

KingGorilla wrote:

And the fact that the key criminal offenders and most violent are those born and raised well after lead levels began starkly declining; that our rising demographic of violent offenders in the modern era was born after 1979? That is the big darn issue I have with the conclusion.

The answer, it turned out, involved "several months of cold calling" to find lead emissions data at the state level. During the '70s and '80s, the introduction of the catalytic converter, combined with increasingly stringent Environmental Protection Agency rules, steadily reduced the amount of leaded gasoline used in America, but Reyes discovered that this reduction wasn't uniform. In fact, use of leaded gasoline varied widely among states, and this gave Reyes the opening she needed. If childhood lead exposure really did produce criminal behavior in adults, you'd expect that in states where consumption of leaded gasoline declined slowly, crime would decline slowly too. Conversely, in states where it declined quickly, crime would decline quickly. And that's exactly what she found.

By the hypothesis, peak lead in the 50's and 60's before the large white flight in the late 60's and early 70's is to blame. It is irrelevant, based on the hypothesis, because it is exposure ages birth to 3 or 4 that is important to factor in.

Following World War II, there was pent-up housing demand in the US, and widespread suburban development took place. In addition, some working-class and middle-class white families felt pressure from increases in minority populations and overcrowding in cities.[citation needed] They moved out to the suburbs, aided by GI loans for purchase, federally subsidized highway construction, and other facilities that made commuting to work easier.

About the 23 year time lag....

Time lags that relate lead exposure to crime trends reflect analysis of a wide range of lags to identify the “best-fit” with the highest statistical significance. In every crime category, the best-fit lag is consistent with lead-induced neurobehavioral damage in the first year of life and the peak age of offending. The best-fit lag for burglary is 18 years, reflecting arrest rates for property crime that have historically peaked at ages 15 to 20 and fallen sharply by age 30. The best-fit for violent crime is 23 years, consistent with historical violent crime arrest rates that peaked at ages 15 to 24 and declined slowly through age 50. The broad category of USA index crime is about 90% property crimes and 10% violent crimes, and the best-fit lag for index crime is 19 years.

http://www.ricknevin.com/uploads/The...

Teenage and young adult incarceration rates are plummeting.

From 2001 to 2011, the incarceration rate for men ages 18 and 19 fell by 43%. The rate for men ages 20-24 fell 29%, and the rate for men ages 25-29 fell 17%. Over that same ten year period, the incarceration rate for men ages 40-44 increased 33%, the rate for men ages 45-54 increased 79%, and the rate for men ages 55 and older doubled.
LobsterMobster wrote:

How I see it, both crime and lead are more prevalent in poor communities. I don't think removing one will prevent the other.

Except that's not what multiple research studies found.

One combed through state crime data and EPA records and found what you would expect if lead was actually the culprit: states that were slow to get rid of leaded gas experienced a slower drop in crime than states that moved quickly to get the lead out.

And another found similar drops in crime that lagged about 20 years in Britain, Canada, France, Australia, Finland, Italy, West Germany, and New Zealand.

That makes it harder to simply claim that its just a poor thing.

Besides, knowing that lead decreases the IQ of children should be enough reason to remove it from poor communities. The future economic contribution of smarter citizens would, as the article shows, far outstrip the cost of cleaning.

KingGorilla wrote:

I did, and it reads like the link between warm weather and crime.

But in the 80's and 90's the most violent offenders were teenagers-the crime rate among those 17-20 was ridiculous. The most violent generation were the people born after lead levels began declining. More to the point, the most violent offenders had not reached maturity in their brains. Even today the largest criminal demographics are those 18-24, who should have the lowest exposures to lead but immature brains.

The growth trend in the last decade is an increase in the crime rate among those 25-34. These are the people who were toddlers as lead was declining sharply, with mature brains but are the only group today whose crime rate is significantly rising. Odds are in another 10 years the 18-24 demo and the 25-34 will be the same.

But what you're saying fits with the model, King. We didn't seriously start to phase out leaded gasoline until 1980. It was 1983 before we were able to get rid of half of all leaded gas, 1986 before we phased out 90% of leaded gas, and another nine years on top of that to get rid of it all together. So that means the most violent generation, as you put it, was actually the last generation of kids who were born--and grew up--with high levels of lead.

And I don't think the crime statistics bear out your predictions, either. The arrest trend from 2001-2010 shows a massive 23.5% decrease in arrests in people under the age of 18 while arrests for people over 18 during that period went up by 1%. We can even go back further and see that between 1995 and 2004 there was a similar 22.1% decrease in arrests in the under 18 group (Table 32).

Also, a word about correlation vs. causality: pirates didn't show their buccaneering spirit by resisting regulations on emissions. Pirates were actually pretty progressive for most of their existence: they relied on wind power, a green and renewable resource, what with all their mainsails and yardarms such. Oil tankers are generally only used by pirates in movies.

IMAGE(http://i1094.photobucket.com/albums/i453/czpv/DH_zps68ca7a33.jpg)

I think things change when we're talking about correlation vs. causality in the case of lead: "A second study found that high exposure to lead during childhood was linked to a permanent loss of gray matter in the prefrontal cortex—a part of the brain associated with aggression control as well as what psychologists call "executive functions"." Not all correlations are just "A is associated with B": the game changes a bit when it's also "there's science behind A causing C, and science behind C causing B" like in this case.

KingGorilla wrote:

It also is not getting into any explanation of male vs female demographics in criminality. Every girl in the 50's, 60's, 70's was exposed to the same amount of lead.

A second study found that high exposure to lead during childhood was linked to a permanent loss of gray matter in the prefrontal cortex—a part of the brain associated with aggression control as well as what psychologists call "executive functions": emotional regulation, impulse control, attention, verbal reasoning, and mental flexibility. One way to understand this, says Kim Cecil, another member of the Cincinnati team, is that lead affects precisely the areas of the brain "that make us most human."

So lead is a double whammy: It impairs specific parts of the brain responsible for executive functions and it impairs the communication channels between these parts of the brain. For children like the ones in the Cincinnati study, who were mostly inner-city kids with plenty of strikes against them already, lead exposure was, in Cecil's words, an "additional kick in the gut." And one more thing: Although both sexes are affected by lead, the neurological impact turns out to be greater among boys than girls.

KingGorilla wrote:

The same for minorities vs whites in that same era.

I would imagine that crime data for minorities for those eras--especially the 50s and 60s--would be a bit dodgy given the racial bias of the time. But the researchers did track the effect down to the city level, which--given white flight--might be a suitable enough stand in. What some consider the inherent criminality of minorities might simply be a much greater exposure to lead.

Just this year, Tulane University researcher Howard Mielke published a paper with demographer Sammy Zahran on the correlation of lead and crime at the city level. They studied six US cities that had both good crime data and good lead data going back to the '50s, and they found a good fit in every single one. In fact, Mielke has even studied lead concentrations at the neighborhood level in New Orleans and shared his maps with the local police. "When they overlay them with crime maps," he told me, "they realize they match up."

Perhaps the thread topic is misleading. The studies and research cited, from the international level all the way down to tracking individuals from birth, focus on violent crime. A lack of impulse control is a main causative factor in that type of crime, so the conclusions don't surprise me at all. What is interesting is that lead levels have been shown to be a greater factor than previously thought.

OG, you are off by 5 years. The Clean Air Act amendment, and subsequent regs on lead in fuel went into effect January of 1975, lead in fuel was reduced by 75 percent on all new production. With a marked decrease of about 50 percent observed lead contamination in the human population by 1980. Those children in that era who had 50 percent less lead contamination, would in turn be responsible for twice the rate of violent crime. A 50 percent decrease in lead contamination within this population that committed double the crime, but the population who was exposed to far more lead was half as violent.

That is what is wrong, the time table is off. Atmospheric lead began to decline in 1975 with the major fall in 1980, in turn water and soil lead declined. The violent crime rate of kids born and raised in this area should be below the rates of the previous sample (kids born in the late 50's and early 60's).

Repeating that improvements varied depending on how fast or slow states adopted certain regs, does not get to the issue that the generation born with declining lead in their bodies was responsible for a 2 fold increase in violent crime in America. Even with no Clean Air Act, if lead contamination remained constant relative to the 50's and 60's, you could not explain the two fold increase in violent crime based on this hypothesis. Atmospheric lead peaked in 1970, began to decline after 1975. By this hypothesis, the people born between 1967 and 1973 would be the ones to exhibit the most violent crimes. That is not what occurred. The sharp double uptick in crime was from the generation of kids who had far less lead in them.

KingGorilla wrote:

OG, you are off by 5 years. The Clean Air Act amendment, and subsequent regs on lead in fuel went into effect January of 1975, lead in fuel was reduced by 75 percent on all new production. With a marked decrease of about 50 percent observed lead contamination in the human population by 1980. Those children in that era who had 50 percent less lead contamination, would in turn be responsible for twice the rate of violent crime. A 50 percent decrease in lead contamination within this population that committed double the crime.

That is what is wrong, the time table is off. Atmospheric lead began to decline in 1975 with the major spike in 1980, in turn water and soil lead declined. The violent crime rate of kids born and raised in this area should be below the rates of the previous sample (kids born in the late 50's and early 60's).

The reduction of lead in gas didn't happen so cleanly, KG.

In 1973 the EPA mandated that one grade of gas be lead free by 1974. This was because of the Clean Air Act and the requirement that cars produced in 1975 had catalytic converters to reduce pollution. Leaded gasoline damaged the catalytic converters.

In 1975, the EPA additionally decided to gradually step down the levels of lead in all grades of gas from 1.7 gram per gallon in 1975 to 0.6 grams per gallon in 1978. And those numbers would be measured by pooled averages calculated quarterly. Small refineries were completely exempted from the law until 1982. The EPA allowed leaded gas to have 1.1 gpg of gas.

In 1985, the EPA moved to further restrict the amount of lead in leaded gas to just 0.1 gpg beginning in 1986.

The final elimination of lead from gas didn't happen until 1996.

And while the amount of lead did decrease in the 80s, that overlooks the fact that as we learned more about the impact of lead on the development of children that the CDC continually lowered the "acceptable" amount of lead that should be found in children's blood. In fact, in 2010 the CDC came out and said that no known safe blood lead level has been identified for children and that levels as low as 5 micrograms per deciliter--about a tenth of "acceptable" levels in 1970--were linked to developmental problems. So while the amount of lead children were exposed to did drop dramatically there was still enough of it to have an effect.

I think you might also be making the assumption that *all* violent crime is linked to lead. If you dig in the article to the study by Reyes you'll see that she says the elasticity of violent crime with respect to childhood lead exposure is approximately 0.8. That means there are most definitely other factors--say the crack epidemic--that could also affect the levels of violent crime.

OG this is what the article says, and this is what I am taking issue with:

Gasoline lead may explain as much as 90 percent of the rise and fall of violent crime over the past half century.

It says to me that gasoline lead is the predominant culprit in big ass font.

I am not arguing the adverse effects of lead on development. I am not arguing that lead poisoning is unrelated to lower cognition, or that lower cognition is unrelated to crime I am not disagreeing that there is no safe amount of lead. I am stating that the claim that atmospheric lead is to violent crime what atmospheric CO2 is to global temperature is wrong and that the numbers are not lining up.

I think that is true King Gorilla. That sentence is saying lead lag is the change of rate in crime.

And thus is the inextricable issue I stated before of the high prevalence of lead poisoning and poverty-living in old and poorly renovated homes, working and living near polluting facilities. Based on these graphs you could also place over them the rise and fall of teenaged births among the urban poor.

I am not saying no factor. I am saying not the predominant factor, that 90 percent is popycock. This is what is called a panacea in sociology. The same problem came from the link of access to abortions and the crime rate, that study ran into similar issues when it came to time lapse adjustments over largely the same time(Roe v. Wade was decided in 1973 when the CAA was passed). The graphs look strikingly similar as well. I also know that given the recent lack of an uptick in crime due to the recession, there is a general dash for explanations of crime beyond economic pressures that dominated the field in the last 2 centuries

KingGorilla wrote:

OG this is what the article says, and this is what I am taking issue with:

Gasoline lead may explain as much as 90 percent of the rise and fall of violent crime over the past half century.

It says to me that gasoline lead is the predominant culprit.

I am not arguing the adverse effects of lead on development. I am not disagreeing that there is no safe amount of lead. I am stating that the claim that atmospheric lead is to violent crime what atmospheric CO2 is to global temperature.

This might be a case of when a journalist quite report the science right.

The actual study (page 32) said that the R2, the coefficient of determination, between lead (23-year lag) and all violent crime was .9. The reporter might have misinterpreted that as saying lead was responsible for 90% of violent crime when, instead, it just meant that the regression line fit the observed data well (really well).

Reyes' study was the only one to make claims on an actual percentage decrease in violent crime. She said the data implied that a 56% decrease in violent crime between 1992 and 2002 could be attributed to the lowering of lead levels.

Check this out, KG: http://yosemite.epa.gov/ochp/ochpweb...

The period of 1976-1980 was when the CDC did a large study of blood lead levels in the American population. That provided a benchmark for those to follow. Afterward, as sources of lead (gasoline, soldered cans, plumbing, paint) were removed, blood lead levels decreased. However, even though the average went down the tail was longer for city centers than it was for urban areas. Violent crime in city centers remained at a high level for much longer, and even went up. There are many other factors besides lead, of course... but the point is that the damage that lead does to the brain is a considerable factor in itself.

The decrease in crime levels has been my focus, too. If someone told me that lead levels were primarily responsible for violent crime, I'd call them wacky. There are many other factors which must be present. Lead levels alone won't make people violent. However, taking lead out of the environment could very well lead to a decrease in violent crime. That's more plausible. The removal of a factor, especially one which affects the brain in the way that lead does, can make a significant difference.

EDIT: By the way, this may also be why criminologists don't look at this as an interesting thing. They may not consider lead to be a causative factor in violent crime, but rather a contributive one even in light of this. I can understand that.

I would be more interested in whether or not our involvement in foreign wars with significant casualties have had a correlation with a drop in domestic (as in country, not home) violence.

My hypothesis is that providing a legitimate outlet for psychopathic behavior which can and does result in a significant percentage of them being killed or significantly wounded has got to have some effect on overall statistics.

Figure that folks with a tendency toward that sort of behavior are less than 5% of the population and join the military in extraordinarily high percentages (e.g.: Tim McVeigh, Lee Harvey Oswald, etc.). And figure additionally that a certain percentage get killed. Figure even further that more end up getting washed out of the military as a result of poor conduct or psychologically unfitness (thus disqualifying them from legal handgun ownership, btw).

I suspect that that has got to have some effect on overall violent crime.

Counterpoint: those numbers may be balanced by otherwise nonviolent people who are driven to psychopathy by the horrors of war.

I don't understand why anyone would fight this conclusion. We know lead is neurotoxic.

Lead in high doses makes people go insane. We know this. Why is it so weird to think that childhood exposure makes people a little bit crazy? Not enough to need a padded cell, but enough to need bars.