This, I think, is one for at least the SD Science Advisory Board, or possibly Cecil himself.
In a recent column, Judy Mann of the Washington Post reported on research connecting lead exposure and crime rates, mentioning research done by Dr. Herbert Needleman of the U. of Pittsburgh School of Medicine since 1979. According to Mann, Needleman estimates that between 11% and 38% of crime in America may be attributable to childhood lead exposure, and he thinks reduced exposure to lead since we started pulling lead out of gasoline may have a lot to do with the largely unexplained drop in crime rates during the 1990s.
This is just the work of one researcher, and I’m reading it through the lens of a columnist who might have a propensity to make more of this finding than is there. Which is why, Cecil (or SD Advisory Panel, or any of the Teeming Millions who are up to date on scientific research in the field), I’d like to know: what’s the Straight Dope on lead and crime?
My WAG is that this is coincidence similar to the drinking bottled water during pregnancy increases birth weight statistical fallacy. Women who drink bottled water can afford better prenatal care and that leads to higher birth weight.
Similarly, people who can afford it, have the lead paint in their homes taken care of. Poor people do not. Also, the economy has gotten pretty damn good in the '90s which lead to fewer poor people. Poor people often commit crimes out of necessity. I doubt it has much to do with lead.
Could it be that the parents who don’t care enough to teach their kids right from wrong are also not going to care enough to repaint their houses if they have lead in the paint? The control group didn’t adjust for the parents’ “give a crap” levels.
I’m not completely dismissing the conclusion, as it seems somewhat reasonable, but it is impossible to account for all variables (even significant ones) in behavioral studies. Maybe kids who are genetically predisposed toward violence are also genetically predisposed to like the taste of dried paint flakes.
Well, the study cited did control for a number of variables, such as parents’ education and occupation, and neighborhood crime rates. It’s hard to adjust directly for ‘give a crap’ levels, but these other factors usually manage to do that pretty well, though indirectly.
Anyone out there with better than a WAG? (With all due respect, I can manage those on my own…)