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Saturday, September 03, 2005

Lead Exposure, Antisocial Behavior, And Intelligence

Somewhere - I cannot remember the source- I ran across an article that explores a connection between lead poisoning and the violent tendencies disproportionate to blacks and Hispanics. The theory goes like this. Blacks are more likely to be poor, and thus more likely to live in older housing coated with lead-based paint. Hispanics face a similar situation, and on top of that, significant amounts of lead are found in some of the candy marketed specifically to that group. Lead has toxic affects that, among other things, adversely affect behavior and could be a contributing factor to the youth violence we see in some parts of the country.

I managed to find a Natural Resources Defense Council report on various health risks to Latinos. This section elaborates on the situation:

The principal source of lead exposure for children is lead-contaminated dust (from lead-based paint), but other sources may have particular implications for Latinos. One such source is lead-glazed pottery, which some tourists and immigrants continue to bring in from Mexico and other countries. Some Latino children may also be eating lead in candy, as reported in an April 2004 Orange County Register investigative story. The article explained how lead-contaminated candies manufactured in Mexico make their way into the U.S. market.

Another factor for increased risk of childhood lead poisoning among Latino immigrants, particularly those of Mexican origin, is the use of certain folk remedies. Such traditional remedies as greta and azarcón, which may contain nearly 100 percent lead and are often used to treat stomachaches, may expose children to dangerously high lead concentrations.

This passage spells out the neurological health risks:

In children, lead is known to cause neurological problems even at tiny doses. Most notably, lead has been associated with a decline in IQ and with learning disabilities, hyperactive behavior, violence, and an increase in antisocial behavior. In adults, lead has been linked to neurological problems, high blood pressure, and kidney problems.

I am not a professional sociologist, but common sense tells me that the level of violence rises exponentially as the number of violence-prone individuals within a population increases. That adds some insight into why certain areas are more riot-prone than others. Evidently, lead removal should be pursued as a measure for long-term crime prevention.

The note on lead's impact on IQ brings back memories of the reactions to the chapters in The Bell Curve addressing racial IQ differences. Here's a sample of the hysteria, from a 1995 article by Fairness and Accuracy in Reporting :

When the New Republic devoted almost an entire issue (10/31/94) to a debate with the authors of The Bell Curve, editor Andrew Sullivan justified the decision by writing, "The notion that there might be resilient ethnic differences in intelligence is not, we believe, an inherently racist belief."

In fact, the idea that some races are inherently inferior to others is the definition of racism. What the New Republic was saying--along with other media outlets that prominently and respectfully considered the thesis of Charles Murray and the late Richard Herrnstein's book--is that racism is a respectable intellectual position, and has a legitimate place in the national debate on race.

Sully recently blogged on his decision to excerpt the book in New Republic:

Liberalism's commitment to political and moral equality for all citizens and human beings is not and should not be threatened by empirical research into human difference and varied inequality. And the fact that so many liberals are determined instead to prevent and stigmatize free research and debate on this subject is evidence ... well, that they have ceased to be liberals in the classic sense.

FAIR and its fellow travelers assumed that the existence of a racial IQ gap necessarily presumes inherent racial superiority. It never occurred to them to consider the possibility that environmental differences could explain such a phenomenon. (I long suspected the education gap to be a factor in the IQ gap; blacks tend to have lower-quality instruction than whites.) At the time The Bell Curve was published, we had already known about the racial disproportion in lead exposure and the relationship between lead poisoning and IQ impairment. It's real estate superiority, not racial superiority.

Perhaps FAIR should have its offices repainted.

Update: Clayton Cramer has some related bloggage on this topic.

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