criminal behavior

What Causes Criminal Behavior? It Might be Lead Poisoning

New research has found a strong association between childhood lead exposure and adult criminal behavior. Previous studies have found links between adult criminality and childhood social influences like parenting, economics, and education, but this study is the first to show such a strong link between a single environmental factor and criminal behavior.

Many Factors Can Contribute to Criminal Behavior in Adults

Over the decades, numerous studies have attempted to understand how conditions and events in childhood influence people later in life. Some studies looking into criminal behavior have found associations between any number of conditions that seem to increase the odds that someone will grow up to commit crimes.

Still, the majority of influences that researchers believe can increase the chances of such behavior involve sociological mechanisms like parenting, income, and social environment. While a seemingly logical conclusion, these studies have mostly avoided looking into more fundamental influences like chemicals and pollutants that may affect a child’s brain development since behavior is still mostly treated as a psychological mechanism and not a biological one.

Now, researchers are taking a fresh look at a handful of studies that covered these types of influences, and according to their recently published research, one toxic material has shown a particularly robust association between child exposure and adult criminal behavior: lead.

Keeping Your Child out of Prison May Simply Involve Getting (and Keeping) the Lead Out

“An evaluation of 17 previously published studies suggests that exposure to lead in the womb or in childhood is associated with an increased risk of engaging in criminal behavior in adulthood,” explains a press release announcing the latest study, “but more evidence is needed to strengthen understanding.”

In their study, lead author and doctoral student Maria Jose Talayero Schettino of the George Washington University (GWU) and her colleagues looked at lead, a substance that has been anecdotally linked to poor health outcomes, especially when exposed to that substance in childhood. As noted, this involved combing through data from 17 previous criminal behavior studies that included information on potential exposure to lead in childhood.

According to the release, their analysis included studies “which employed a variety of methods for measuring lead exposure—using blood, bones, or teeth—and addressed the effects of exposure at different ages, including in the womb or early childhood, later childhood, and adolescence or adulthood.”

In some of those studies, no link was found between lead exposure during childhood and criminal behavior in adulthood, while others found an association between lead and anti-social behavior but not criminal behavior. However, the majority of the studies did find what appeared to be a link, and often a strong one.

“Several studies found links between early childhood exposure to lead and later arrests, including drug-related arrests,” they note.

Notably, the researchers point out that lead exposure in childhood is linked to a number of other poor health outcomes, including “cardiac issues, kidney damage, immune system dysfunction, reproductive problems, and impaired neurodevelopmental function.” As a result, they were not surprised to see that this extremely toxic substance could potentially impact behavior in adulthood.

According to a statement released by GWU, lead exposure in utero or during childhood can come from a number of different sources. These include “pollutants from industrial waste, recycling batteries, paints with lead content, various food sources and household products, such as children’s toys, ceramics and cookware.”

Cookware was of particular concern, the researchers explain, including pottery from Asia, aluminum cookware from Africa, and artisanal pottery from Mesoamerica “not certified to be lead-free.”

Criminal Behavior and Lead Exposure Need More Study but Prevention Should Start Immediately

The researchers are quick to point out that although the association they found was a strong one statistically across the greater population, it was not necessarily the case for individuals. So even if your child has been exposed to high amounts of lead, there is no guarantee that they will grow up to be a criminal.

Also, the researchers looked for statistical bias in the studies they analyzed using a tool known as ROBINS-E and found that at least some of them did indicate some bias in their results. However, correcting for that bias was not enough to eliminate their core finding.

“There is no safe level of lead exposure for children, and countries should extend all efforts to protect children and pregnant persons from lead containments,” said Talayero Schettino. “The evidence in the systematic review supports a strong action by governments and society to act to protect those in most vulnerable conditions.”

Ultimately, the researchers said that the link they found was strong enough that they recommended steps be taken to help eliminate lead exposure in childhood.

“While more individual-level data needs to be collected to verify the connection of the effects of lead exposure during childhood and criminal behavior in adulthood, the evidence we found points in the direction of lead exposure being associated with biological effects in children that have long-term behavioral consequences,” said Talayero Schettino. “The data clearly demonstrates the need for all countries to implement policies to prevent lead exposure.”

Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at, or email him directly at