How new research can explain the unexpected world wide trends in violent crime reduction.
When someone mentions ‘Lead’ what springs to mind? Chemistry enthusiasts are shouting arrogantly at their screens that, “it it has an atomic number of 82” and, “that the symbol for it is ‘Pb’ which comes from leads Latin name Plumbum”. Plumbers are well acquainted with Lead from their faithful solder, used to join copper pipes making a firm and water tight seal. Roofers will know lead only to well as its malleable surface is perfect for the flashing on the roofs of your houses. But for the rest of us, I can safely assume that we are thinking of a somewhat uninteresting lump of grey metal that isn’t all that good for us when it is in our bodies. But we are wrong! Lead is not an uninteresting lump of grey metal that is rather bad for you, but instead, the most aggressive violent criminal that society has ever seen…
Crime, in western society on a whole, is falling. In the UK there were 9.1m reported crimes in 2011/12, according to the Crime Survey for England and Wales. That is down from 9.7m the previous year, and a whopping 27.2% lower than ten years ago. It is not just the petty stuff. The Office for National Statistics agrees that violent crime had fallen by 7%, and the murder rate has fallen by 14%. Over in the States it is the same story. Murder and robbery rates nearly halved from 1991-98. This phenomenon has saved thousands of lives and spared many more potential victims of crime. The pace of the reduction slowed in the late 90’s but new FBI figures show another sharp drop in crime that began around 2008 and is still continuing now, despite the recent high unemployment. This trend is happening all over the world. But, why?
Many people have stepped up to the plate to explain why this is happening. The first person to stamp his claim that he was the reason the sharp fall in crime was the former Mayor of New York, Rudy Giuliani. In 1982, along with a fair few social scientists, he argued that repairing vandalism in urban areas prevented further crime, an idea known as ‘Broken Windows Theory’. This is still a prominent idea in criminology, but here at Reality Bites we are not buying it. Crime fell in a vast amount of cities over that period, and most did not change their policing policy in the slightest. Whilst this idea of nipping crime in the bud by clamping down on less serious crimes may well affect crime rates, it can’t be responsible for the overall reduction in worldwide violent crime. Sorry Giuliani, no credit for you on this one.
Unlike Rudy Giuliani’s claims, there are lots of proposed theories that are highly likely to be linked to this dramatic drop in crime. A study released last month by Researchers in Texas – working with the Centre for European Economics – suggested video games were keeping young people off the streets, and therefore, away from crime. John Conklin, a sociologist at Tufts University, argues a significant factor behind the fall in crime in the 1990s was the fact that more criminals were locked up and therefore making them unable to offend. A controversial theory was also put forward by economist Steven Levitt, arguing that the
in America after the Supreme Court ruling in 1973 on Roe Vs Wade meant that fewer children were born into socially deprived families. Levitt argues that this stopped unwanted babies in the 1970s and 80s from becoming adolescent criminals in the decades that followed. These can all explain parts of the trend but we are yet to see an argument that shows the driving force that is lowering the crime rate. That was until we came across research from Rick Nevin.
back in 1994 Nevin was working for the US Department of Housing and Urban Development seeing if there would be any befits from removing lead paint from old houses. Recent studies had indicated that Lead poisoning can lead to complications later in life, including lower IQ, hyperactivity, behavioural problems, and learning disabilities. Nevin was the first person to float the idea that maybe reducing lead exposure had an effect on violent crime too?
For the non mechanics among us, I must tell you about a man called Thomas Midgley. An Ohio born inventor who’s mechanical genius was only surpassed by a amazing ability for his inventions to, unintentionally, destroy the world. After inventing CFCs (a gas used in refrigerants, but you may have come across them before they was phased out in aerosol cans) which after he died scientist discovered were destroying the ozone, Midgley set his mind to a completely different problem. A long standing problem with diesel engine at the time was a problem called ’Engine Knock’, where a distinctive knocking noise is caused by the air and fuel mixture being too lean. Midgley realized that by adding lead to petrol solved the problem, but unknown to him, left large amounts of Leaded Gasoline in the air. This was later banned at various stages around the world, and we began to see atmospheric lead levels slowly decline.
Nevin realised this when researching crime rates so compared them to charts showing the rise and fall of atmospheric lead. The charts show Lead emissions rose steadily from the early ’40s until the early ’70s. Then, as leaded gasoline was banned, and unleaded was introduced, emissions plummeted. Violent crime rates mirrored this upside-down U pattern, only offset by about 20 years. The data showed in places where uses of leaded gasoline declined slowly, so did crime. Where it declined quickly, crime also declined quickly. Nevin concluded that if you add a lag time of 23 years, lead emissions from auto mobiles explain the vast majority of the variation in violent crime. Toddlers who inhale high levels of lead in the ’40s and ’50s really were more likely to become violent criminals in the ’60s, ’70s, and ’80s. His research showed this was not just in America. Everywhere he could get crime statistics, and data on atmospherics lead levels, you can see an identical situation. Further studies on this by Howard Mielke, working with Sammy Zahran, furthered this research and found that there was an over whelming correlation of atmospheric lead levels and crime even on a street by street basis. Looking at six US cities they found that even at this concentrated level, when they overlay maps showing high quantities of atmospheric Lead with the crime hot spot maps, they match up.
This idea is not only backed up by statistics, but by common sense. Top scientists have known for years that lead poisoning causes damage to our brains. In 1995, the American Academy of Paediatrics reviewed 18 scientific studies on the correlation between a child’s mental abilities and lead levels in their blood and found that the relationship between lead levels and IQ deficits was “remarkably consistent”. A study by Herbert Needleman in 1996 measured boy’s behaviour at age 7 and again at age 11and found that those who had more lead in their bones consistently had more reports of aggressive and delinquent behaviour, and problems paying attention. They were more likely to engage in antisocial activities like vandalism, truancy, and shoplifting. Furthermore, their behaviour got worse as they grew older. There is no end to studies that link lead to these types of behaviours. Modern research shows that lead poising tends to affect our use of our pre-frontal cortex – the part of the brain associated with personality expression, decision making and moderating social behaviour – so baring in mind this research, can we be surprised with Nevin’s findings?
This isn’t a problem that will be solved over night. Even if we did remove every drop of atmospheric lead from our streets we would not completely solve violent crime as there is a vast amounts of causes for it, but can we really ignore this? Like most good science, this has fallen on deaf ears. There is minimal political push around the world for this to be addressed. Most politicians, like good old Rudy Giuliani, are happy claiming that there policies are the reason for this drop in crime, but like usual statistics can expose what is really going on. There are two things we believe that everyone should take from this. First, around the world we are cutting Environmental health departments as we strive to save money, cut deficits and reduce country debts. But is this really saving money? If you add up the cost of processing all that crime; including policing, court fees, prisons, etc it would tower over spending on the environment. Support our environmental departments; don’t let politicians talk you into believing that we cannot afford to run them. And second, if you ever plan on being an inventor, please read more about Thomas Midgley and whatever you do, don’t follow in his footsteps.
Nevin – Understanding international crime trends: The legacy of preschool lead exposure
Howard Mielke – The urban rise and fall of air lead (Pb) and the latent surge and retreat of societal violence