MOST sensible people are skeptical of so-called silver bullet theories that attempt to perfectly explain or solve massive, complex problems with one simple fact or solution.
"For every complex problem, there is a solution that is simple, neat, and wrong," 20th-century American sage H.L. Mencken is quoted as saying.
Violent video games are not the cause of all school shootings. Sibling birth order does not explain the personality development of every human. Napster did not single-handedly kill the recording industry.
But what if there was a theory that meshed with all of the numbers? What if one small change made throughout the world over the past few decades, including in 1990 in Canada, altered the path of modern human history? Cutting right to the chase: What if the removal of lead from automobile gasoline explained the fall of crime in the 20th century and ushered in a new era in which streets and homes and buses and pretty much every location in the world were safer now than they were 20 years ago and will only continue to get safer? That would be a pretty interesting theory.
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The idea that lead poisoning from automobile emissions caused a massive spike in crime is not a new one but it was amplified earlier this year when Mother Jones magazine published an article written by Kevin Drum entitled America's Real Criminal Element: Lead. Drum drew on the work of researcher Rick Nevin who in a 2000 paper in a journal called Environmental Research compared children's blood lead levels with subsequent changes in IQ. Nevin noted that of all age groups, very young children face the greatest risk of IQ losses due to lead exposure, especially during the first three years of life when their brains are developing at a rapid rate. He came to the conclusion that the "trends in IQ, violent crime and unwed pregnancy show a striking association with changes in blood lead levels and gasoline lead exposure for very young children."
The theory, in simplified terms, is that exhaust spewed out by vehicles using leaded gasoline affected the behaviour and IQ of children. That drop in IQ then manifested itself 16-20 years later when those same toddlers became adults who were more likely to commit crimes. When leaded gasoline was phased out and banned in jurisdictions around the world, the low-level lead poisoning stopped affecting young children and when those unleaded kids grew up, they committed crimes at a much lower rate.
Nevin also predicted that "if the association between gasoline lead and social behaviour continues into the future, then violent crime and unwed teen pregnancy could show dramatic declines over the next five to 10 years."
Leaving aside the unwed pregnancy side of the equation, Nevin's prediction about crime, made more than 13 years ago, turned out to be pretty bang on.
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Let's go back 100 years. Early in the 20th century the automotive industry was looking for a fuel additive that would improve engine performance and reduce those banes of early automobile engines, knocking and pinging. In 1921, engineers from General Motors reported great results for their first test of tetraethyl lead as an additive. GM soon began touting the compound as the saviour of the automotive industry. There was a slight hiccup in the summer of 1924 when 15 workers who were producing the additive at refineries in Ohio and New Jersey went mad and died, but that wasn't enough to stop the wheels that were already in motion. Leaded gasoline enjoyed a great run - it helped win the Second World War and make the American automotive industry a juggernaut - until the 1970s when health concerns finally reached the ears of lawmakers. In 1973, both the Environmental Protection Agency in the United States and Health Canada began the process of phasing out leaded gas and it was completely banned in 1990 in Canada and 1995 in the United States.
Now let's look at crime. Last year Statistics Canada released detailed police-reported crime rate numbers from 1962 to 2011. Crime rate is a per capita statistic that gives the number of crimes reported per 100,000 people. In 1962, the total crime rate in Canada was 2,771 per 100,000 people. For violent crimes the rate was 221. Both of those numbers climbed nearly every single year until peaking in the early 1990s. In 1991, the total crime rate reached a high of 10,342 - that's more than 3.5 times the rate in 1962 - while the violent crime rate peaked at 1,084 in 1992, nearly five times the rate that was reported 30 years prior.
Since 1993 the crime rate has decreased nearly every single year and it continues to do so today. In 2011, the rate was back down to 5,757 total and 866 for violent crimes.
There were a lot of theories about what caused this mountain of crime that peaked in the early 1990s and then dropped back down to earth. The theories ranged from such things as echo boom demographics to crack cocaine to recession economics to the legalization of abortion. None of them held up perfectly under intense scrutiny.
So what about the leaded gasoline theory? If you do some simple splicing of the crime statistics and the stats for gasoline, the numbers jump off the page. Take 1973 as a landmark. Leaded gasoline was at its peak, with unleaded just coming onto the scene. What happens when you jump exactly 18 years ahead and those toddlers born at the height of the leaded gas era turn into adults? Now you're in 1991 and the crime rate is at a record high. Now follow the curve of leaded gasoline use as it drops through the mid-1970s and '80s. Jump ahead once more to the mid-1990s and early2000s and watch as the crime rate - set now by young adults who were not exposed to as much lead exhaust when they were children - mimics the same downward curve traced two decades earlier by leaded gas. Interesting.
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The immediate and obvious rebuttal to the leaded gasoline theory is that correlation does not imply causation - just because the stats in Canada show that the trends in leaded gasoline use and crime are matched when an 18-year gap is inserted doesn't mean that leaded gasoline caused children to grow up to commit more crimes.
The numbers, however, hold up no matter how wide you expand the scope. Nevin reappeared in Environmental Research in 2007 with data showing a very strong association between preschool blood lead and subsequent crime rate trends over several decades in not just the United States and Canada but also France, Australia, Finland, Italy, West Germany and New Zealand.
Kevin Drum's article in Mother Jones cited other research that found similar results on state-by-state, city-by-city and even neighbourhood-by-neighbourhood levels in the United Sates. "In states where leaded gasoline declined slowly, crime declined slowly. Where it declined quickly, crime declined quickly," Drum summarized.
The great news in this story is that crime continues to go down all over the map. Looking locally, in British Columbia there were 76,767 total violent offences reported in 2002, according to the Police Services Division, Ministry of Public Safety and Solicitor General. In 2011, that number was down to 66,784. Over that time span the crime rate for all criminal code offences (excluding traffic offences) in the province dropped from 115.0 in 2002 to 78.9 in 2011.
Moving even closer to home, the total crime rate over that same time span dropped from 108 to 81 in the City of North Vancouver, from 59 to 43 in the District of North Vancouver and from 61 to 40 in the District of West Vancouver. Those are all substantial drops for a 10-year span.
Throughout these regions and time periods there have been many people stepping forward to assign or take credit for the dropping crime levels. The most famous is likely the "broken windows" policy instituted in New York City by Mayor Rudy Giuliani after he was elected in 1993. Repairing vandalism and painting over graffiti in order to boost community pride seemed to work. Crime dropped almost immediately and continued to go down, earning great praise for Giuliani and the broken windows system.
More recently on this side of the border the federal Conservative government - just a few months after they passed their hotly debated omnibus crime bill - took credit when Statistics Canada announced in 2012 that the crime rate was the lowest since 1972.
"Crime rate down 6% - shows #CPC tough on crime is working," Public Safety Minister Vic Toews wrote on his Twitter feed.
Policies such as broken windows and the actions of the tough-talking Conservative government no doubt had some effect on crime in their respective jurisdictions, but is it possible that crime fighters the world over were great benefactors of policy changes that were actually set in motion more than 40 years ago?
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This wouldn't be the first time lead has done a lot of damage to a society. The word plumbing comes from the Latin word for lead, plumbum. Many modern scholars, with Canadian researcher Dr. Jerome O. Nriagu at the forefront, argue that the use of lead in water pipes and many other forms resulted in widespread incidences of gout among the Roman aristocracy 2000 years ago. Gout is a symptom of chronic lead poisoning. Nriagu described a syrup, used to flavour wine, that was made by simmering grape juice in lead pots.
"One teaspoon of such syrup would have been more than enough to cause chronic lead poisoning," wrote Nriagu in a book on the subject. Lead poisoning is often cited as one of the factors that caused the downfall of the Roman Empire, one of the greatest realms the world has ever known. Emperor Nero, rumoured to have worn a breastplate of lead to strengthen his voice, is famously described as singing and fiddling while Rome burned.
Coming back to the present day, the continuously dropping crime rate - whether it's fueled by unleaded gasoline or not - has some people questioning the Canadian federal government's "tough on crime" stance noted above by Vic Toews.
The Conservative Party of Canada, took power in 2006. According to Public Safety Canada, the country spent $1.69 billion on corrections - both in capital spending and operations - in 200506. By 2009-10 that number was up to $2.3 billion, an increase of more than $600 million in annual spending, and it's continued to go up. The incarceration rate in Canada also rose during that time, from 107 per 100,000 people in 2006 to 117 in 2011. These recent increases in prison spending and population come despite a crime rate that has dropped steadily since 1991.
"We're seeing (incarceration numbers) continue to go up and I guess the question for Canadians is why? Does this make sense?" said Tim Veresh, executive director of the John Howard Society of British Columbia, a non-profit organization that works to promote effective, just and humane responses to the causes and consequences of crime. "Violent crime, which we should be most concerned about, is on the decline, why are the (incarceration) numbers going up? Therefore, who are we incarcerating?"
Canadians certainly want to see criminal behaviour stopped, said Veresh, but added he doesn't think the money is being spent correctly.
"The investment hasn't been in rehabilitation, the investment has been in security," he said. "When you pass laws and legislation that start to catch up individuals who maybe are not entrenched in the criminal lifestyle, I think then legislation can be problematic. The question to me is, 'If you're getting tough on crime, what are you doing with the individuals that you're getting tough on? If it's just kicking them into prison and being harsher to them, they're probably going to come out being harsher criminals."
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The leaded gasoline crime theory is certainly an intriguing one but it still seems like it needs more work or, at the very least, more champions if it is to be widely accepted.
Veresh said the Mother Jones article created a buzz in his field but added he thinks the leaded gasoline theory needs more research behind it.
"There are many other factors other than the elimination of lead in our world that may be influencing a drop in crime," he said, adding that other trends fit fairly well with the crime curve.
"By getting rid of disco music, it seems like it's followed that trend downward," he said with a laugh. "Maybe the introduction of rap music has dropped violent crime."
Joking aside, Veresh pointed at drug-seeking behaviour of addicts who'll smash the windows of every car on a street to steal a few pennies as an area that is not being properly addressed by the criminal justice system.
"If you look at property crime trends they're not dropping as quickly as violent crime, and that would speak to the economic aspects. When we look at individuals who are most often addicted to crime, they're feeding a drug habit."
The North Shore News contacted several Lower Mainland university departments - ranging from Criminology to Health Sciences to Neurology to Population and Public Health - for some local expert commentary on this story and of those that responded, each replied that they did not have the expertise to weigh in on the subject and were not aware of this as a hot topic of discussion in their field. One reason for this may be that it is a theory that does not fit nicely into one discipline. It is at once a science story and a medical story, a crime story and an environmental story.
In reading the research that does exist it seems clear that the removal of leaded gasoline is not the one silver bullet that killed crime, but it is likely one big piece of the puzzle. And it does make for an interesting story - one that might prove to be a cautionary tale in the history books of the future. It's almost hard to wrap your head around it all - leaded gasoline poisoned an entire generation, pushing more and more people down the IQ slide into a life of crime.
It all almost feels like something out of a comic book. How would a super villain slowly drive the world into madness? Wouldn't that super villain dream up a scheme that would see a subtle poison spit out the back of a ubiquitous piece of machinery that could be found zipping up and down every street in the world?
There isn't a super villain in this story. There are, it seems, some folks who were greedy, naïve, easily coerced and, well let's face it, slightly villainous enough to allow centuries' of warning about the dangers of lead to go unheeded so that the powerful automobile and petroleum industries could thrive.
The leaded menace may now be tamed - in gasoline at least, other sources such as lead paint and windows in older homes are still serious concerns worth addressing - but there are definitely lessons to be learned from the story of the poison in the gas tank.
At the very least, it's a reminder that humans as a species - in this age of high-tech wizardry, booming industry and the unquenchable thirst for resources - need to be very aware of what they are doing to our environment and, in turn, what that environment is doing to them.
1991 Exactly 18 years after the height of the leaded gasoline era, the crime rate hits a massive peak in Canada. The crime rate has dropped continuously since that peak in 1991.
1973 The height of leaded gasoline use in Canada. From 1973 on, unleaded gasoline is phased in, dominating the market by 1985. In 1990 leaded gasoline is banned completely.
CANADA'S crime rate per 100,000 of population peaked in 1991, 18 years after the height of leaded gas use. It's declined ever since.