Tag Archives: environmental racism

Kevin Drum provides an overview and update of the hypothesis in his detailed post An Updated Lead-Crime Roundup for 2018. In short,

The lead-crime hypothesis is pretty simple: lead poisoning degrades the development of childhood brains in ways that increase aggression, reduce impulse control, and impair the executive functions that allow people to understand the consequences of their actions. Because of this, infants who are exposed to high levels of lead are more likely to commit violent crimes later in life.

He notes further down in the article that

It’s important to emphasize that the lead-crime hypothesis doesn’t claim that lead is solely responsible for crime. It primarily explains only one thing: the huge rise in crime of the 70s and 80s and the equally huge—and completely unexpected—decline in crime of the 90s and aughts. The lead-crime hypothesis is the answer to the question mark in the stylized chart below:

The post has useful graphs for QL based courses, provides an overview of the hypothesis, and the Statistics Projects section of this blog has lead-crime data for projects.

Kevin Drum answers the question in his post A Little Bit of Chart History for Wednesday. The phase out started in 1975. Why?

According to Nussbaum, EPA wanted places like California to reduce smog, and that meant cars would have to be fitted with catalytic converters. However, since gasoline lead ruins catalytic converters, refineries needed to produced unleaded gasoline. This was the initial impetus behind unleaded gasoline. The fact that it also reduced atmospheric lead was basically a happy accident.

Once that was done, however, EPA started looking more closely at the health effects of lead. It was no secret that high levels of lead poisoning were dangerous, but new research was showing that even moderate levels could be dangerous, especially in young children. So now EPA had two reasons to phase out leaded gasoline.

Drum’s post provides nice historical context on leaded gas, including this graph that may be the first graph produced showing a correlation between lead in blood and lead in gas (excellent artifact for use in a classroom). Read the article to find out about President Carter’s connection in all of this.

For further information read Drum’s essay Lead: America’s Real Criminal Element, published in Feb 2016. The lead crime connection has an element of environmental racism, which is not often discussed. In Statistics Materials you’ll find lead and crime data for linear regression and further information.

Kevin Drum keep us updated on the lead crime hypothesis. His latest post on this topic: Lead Update: White Folks and Alabama Prisoners.

The lead hypothesis predicts that young cohorts are less crime prone than older cohorts, so their share of the jail and prison population should decline. It predicts that black crime rates will drop faster than white crime rates. And it also predicts that small-city crime rates will drop faster than big-city crime rates. All of these things have turned out to be true.

The lead crime connection has an element of environmental racism, which is not often discussed. In Statistics Materials you’ll find lead and crime data for linear regression and further information.