When I wrote my big piece last year about the connection between childhood exposure to lead and rates of violent crime later in life, one of the big pushbacks came from folks who are skeptical of econometric studies. Sure, the level of lead exposure over time looks like an inverted U, and so does the national rate of violent crime. But hey: correlation is not causation.
I actually addressed this in my piece—twice, I think—but I always felt like I didn't address it quite clearly enough. The article spent so much time up front explaining the statistical correlations that it made the subsequent points about other evidence seem a bit like hasty bolt-ons, put there mainly to check off a box against  For that reason, I'm pleased to recommend Lauren Wolf's "The Crimes Of Lead," in the current issue of Chemical & Engineering News. It doesn't ignore the statistical evidence, but it focuses primarily on the physiological evidence that implicates lead with higher levels of violent crime: Research has shown that lead exposure does indeed make lab animals—rodents, monkeys, even cats—more prone to aggression. But establishing biological plausibility for the lead-crime argument hasn’t been as clear-cut for molecular-level studies of the brain. Lead wreaks a lot of havoc on the central nervous system. So pinpointing one—or even a few—molecular switches by... |
