A 1995 article published in “The Weekly Standard” under the vaguely terrifying title “The Coming of the Super-Predators” predicted an anarchistic future in the United States. “On the horizon,” it reads “are tens of thousands of severely morally impoverished juvenile super-predators. They are perfectly capable of committing the most heinous acts of physical violence for the most trivial reasons.” The article was one of a number of similarly-themed pieces written in the early-to-mid 90s. These articles postulated a dystopian future in which legions of morally bankrupt psychopathic “super-predators” would wreak havoc on the very fabric of society; they were an impending savage horde poised to flood the United States with crime.
It came as a bit of a surprise to sociologists and criminologists when the exact opposite happened: crime rates plummeted. A 1999 paper published in the “Annual Review of Sociology” proclaimed that “the United States in the 1990s has experienced the greatest sustained decline in violent crime rates since World War II.”
For years the 1990s crime dip has been a topic of interest and debate among sociologists and crime experts. Explanations have been tendered that run the entire spectrum of plausibility, with everything from the legalization of abortions to smarter policing getting credit. Recently, a new theory has surfaced which implicates a different sort of “criminal element:” lead.
According to an article published in Energy Policy in 2001, leaded gasoline hit the market in 1923 after it was found to improve engine performance. For the next sixty years, Americans propelled themselves from sea to shining sea expelling clouds of toxic lead freely into the atmosphere. This lead made its way into the blood of America’s youth, and from there into their brains.
“One consequence of lead is damage to a group of structures referred to as the limbic system” explained University of Wyoming neuroscience professor Dr. Francis Flynn. “These brain structures are associated with the control of emotion. Lead toxicity also impairs learning by damaging certain brain areas such as the amygdala.”
Lead exposure in children has been linked to development of attention deficit hyperactivity disorder. ADHD is in turn linked to criminal behavior.
“Adults with ADHD are oftentimes characterized by affective volatility, occupational instability, poor social relationships and impulsive and self-destructive behaviors,” according to the Journal of Clinical Psychiatry.
“Young adults with a history of ADHD are more likely than those without such history to have a personality disorder, particularly antisocial, histrionic, or borderline personality disorders” the Journal concludes.
These personality traits lend themselves to criminal behavior – those who habitually break the law tend to be emotional and impulsive, with a poor capacity for self-regulation.
According the Energy Policy article, the Clean Air Act was signed into law by President Nixon in 1970. By 1986 leaded gasoline had been almost completely phased out of use in the United States.
“The removal of lead from gasoline and paint in the 1970s was a significant public health success and subsequently, average blood lead levels have declined considerably” summarizes the Energy Policy paper.
The lead-crime theory explains the 90s precipitous decline in lawlessness as a simple function of decreased lead exposure. Once the additive was banned from gasoline – as well as a number of other industrial applications – it no longer posed a significant threat to cognitive development. Thus, just when the theoretical wave of young super-predators was supposed to devastate the United States, the nation instead got a generation of psychologically healthy and lead-free youth.”
Explaining behavioral trends that span a country of three hundred million people is a devilishly complex issue. While it’s likely true that a number of other external factors at the very least contributed to the 1990s crime drop, lead exposure certainly presents a compelling argument.
