Photo by x-eyedblonde from Flickr.

A few years ago, the celebrated economist Steven D. Levitt argued in Freakonomics that the legalization of abortion in 1973 was one of the primary reasons for the drop in crime in the 1990’s, a period when the first generation of children born after Roe v. Wade would enter their twenties, statistically the most violent period of one’s life span. Now a new economist, one by the name of Jessica Wolpaw Reyes from Amherst University, has tried to explain the precipitous drop in crime during the 1990’s, arguing that the drop in crime can be traced back to the reduction of lead in gasoline from the late 1970’s and early 1980’s. “Childhood lead exposure,” Reyes writes, “can lead to psychological traits that are strongly associated with aggressive and criminal behavior.” Of course, the opposite is also true: not being exposed to lead reduces violent tendencies.

Like Levitt’s claim, the lead thesis has been subject to a certain amount scrutiny and, at times, doubt. But Reyes has further opportunities to prove her findings. In places like Venezuela, where lead gasoline has just been fazed out, Reyes, in twenty years time, will be able to see if the connection between lead and violent crime is not just isolated to the United States.

Read Dr. Reyes paper here.

Read what the New York Times Magazine has to say here.