Yesterday’s Washington Post ran an article that I found really provocative, linking the drop in crime in recent decades to… um, lead poisoning.
The general idea is that children who are exposed to lead are more prone to committing violent crime as adolescents presenting, according to the article, “a unifying new neurochemical theory for fluctuations in the crime rate.”
Sounds really good. Too good, in fact. I’m wary of “unifying theories” with such sweeping implications.
There is apparently a lot of literature linking lead exposure to aggressive behavior. But it’s a big step from that to linking crime rates across the world to lead levels.
The article is based on the work of economist Rick Nevin, who looked at nine countries with different abortion rates, police strategies, demographics and economic conditions and found that up to 90% of the variation in violent crime in these countries could be explained by lead.
In the U.S., for example, children were exposed to lead — in household paint at the turn of the 20th century and in gasoline fumes after World War II — and in each case, violent crime peaked roughly 20 years later. Much of the lead in gasoline was eliminated by the mid-1980s explaining, according to Nevin, the drop in crime in the 1990s (what do you have to say that, Rudy Giuliani?), and because this had the biggest impact on inner-city neighborhoods, Nevin says, violent crime in those neighborhoods has declined faster than the overall crime rate.
I know the writer, Shankar Vedantam, and deeply respect his journalistic abilities, so I’m sure he checked out the credibility of this research. But I would have felt better if pretty much the only other expert quoted in the article hadn’t been the editor of the journal, Environmental Research, in which Nevin has published most of his work. The article says Nevin’s work, and the other research that supports this hypothesis, hasn’t received much attention. If it’s good science, why ever not??