Real villain behind violent crime – Lead in gasoline?

Mother Jones article says that new research finds Pb is the hidden villain behind violent crime, lower IQs, and even the ADHD epidemic. Many disagree.

In America's Real Criminal Element: Lead (Jan/Feb 2013 issue of Mother Jones), Kevin Drum discusses different theories for what was responsible for the crime wave of 1990s. Was it a theory of crime fighting called "broken windows" advocated by Mayor Guiliani?

... ... For one thing, violent crime actually peaked in New York City in 1990, four years before the Giuliani-Bratton era. By the time they took office, it had already dropped 12 percent.

Second, and far more puzzling, it's not just New York that has seen a big drop in crime. In city after city, violent crime peaked in the early '90s and then began a steady and spectacular decline. Washington, DC, didn't have either Giuliani or Bratton, but its violent crime rate has dropped 58 percent since its peak. Dallas' has fallen 70 percent. Newark: 74 percent. Los Angeles: 78 percent.

There must be more going on here than just a change in policing tactics in one city. But what?

Other theories considered include

  • Crime goes down when the economy is booming and goes up when it's in a slump.
  • crime drops in big cities were mostly a reflection of the crack epidemic of the '80s
  • demographics: As the number of young men increases, so does crime.

but none of them are supported by data. However, there is another theory proposed by Rick Nevin: exposure to tetraethyl lead, the gasoline additive.

Crime rate vs Gas LeadThis paper claims that if you add a lag time of 23 years, lead emissions from automobiles explain 90 percent of the variation in violent crime in America.

Additional studies looked at crime trends around the world (PDF), which showed good match between the lead curve and the crime trends in several countries.

Read more.

See also

What do you think - is lead the big culprit in explaining crime trends?