Lead and Crime: Is Correlation Also Causation?

Fight disinformation: Sign up for the free Mother Jones Daily newsletter and follow the news that matters.


A big chunk of the evidence linking gasoline lead emissions to violent crime rates is based on statistical analysis. This naturally leads to the criticism that correlation is not causation, so we don’t really know if lead caused crime rates to go up and down. If you’re curious to learn more about this, Rick Nevin has just posted a short paper titled “Lead and Crime: Why this correlation does mean causation.” Here’s a small excerpt that addresses just the statistical evidence:

The key statistical issue that needs to be addressed by the correlation-never-means-causation crowd is whether they honestly believe that:

  • The observed association between lead used in paint and USA murder rates from 1901 to 1960 with a time lag close to the peak age of homicide offending was a coincidence; 
  • The association between USA gasoline lead and violent crime from 1964-1998 with a similar time lag was another coincidence;
  • The “experimental evidence” from violent crime since 1998 (including a 45% drop in the juvenile violent crime arrest rate from 1998-2011) tracking earlier trends in lead exposure is a coincidence;  
  • Analysis of crime in nine nations shows the same consistent relationship between lead exposure and crime trends through 2002, with statistical best-fit lags that reflect the peak age of offending for each crime category, by coincidence;
  • This consistent relationship within every nation studied happens to explain otherwise bewildering changes over time in USA and Canada crime rates relative to Britain, France, and Australia, by coincidence;
  • Experimental evidence from international crime trends since 2002 tracking earlier trends in lead exposure in every nation is also a coincidence.

There’s much more at the link, all based on a 9-part test proposed in 1965 by Austin Bradford-Hill for distinguishing mere correlation from true causation. Nevin examines a broad range of evidence, including statistical studies, longitudinal studies, medical studies, imaging studies, and more. It’s worth a look if you’re still skeptical about the lead-crime connection.

WE'LL BE BLUNT.

We have a considerable $390,000 gap in our online fundraising budget that we have to close by June 30. There is no wiggle room, we've already cut everything we can, and we urgently need more readers to pitch in—especially from this specific blurb you're reading right now.

We'll also be quite transparent and level-headed with you about this.

In "News Never Pays," our fearless CEO, Monika Bauerlein, connects the dots on several concerning media trends that, taken together, expose the fallacy behind the tragic state of journalism right now: That the marketplace will take care of providing the free and independent press citizens in a democracy need, and the Next New Thing to invest millions in will fix the problem. Bottom line: Journalism that serves the people needs the support of the people. That's the Next New Thing.

And it's what MoJo and our community of readers have been doing for 47 years now.

But staying afloat is harder than ever.

In "This Is Not a Crisis. It's The New Normal," we explain, as matter-of-factly as we can, what exactly our finances look like, why this moment is particularly urgent, and how we can best communicate that without screaming OMG PLEASE HELP over and over. We also touch on our history and how our nonprofit model makes Mother Jones different than most of the news out there: Letting us go deep, focus on underreported beats, and bring unique perspectives to the day's news.

You're here for reporting like that, not fundraising, but one cannot exist without the other, and it's vitally important that we hit our intimidating $390,000 number in online donations by June 30.

And we hope you might consider pitching in before moving on to whatever it is you're about to do next. It's going to be a nail-biter, and we really need to see donations from this specific ask coming in strong if we're going to get there.

payment methods

WE'LL BE BLUNT.

We have a considerable $390,000 gap in our online fundraising budget that we have to close by June 30. There is no wiggle room, we've already cut everything we can, and we urgently need more readers to pitch in—especially from this specific blurb you're reading right now.

We'll also be quite transparent and level-headed with you about this.

In "News Never Pays," our fearless CEO, Monika Bauerlein, connects the dots on several concerning media trends that, taken together, expose the fallacy behind the tragic state of journalism right now: That the marketplace will take care of providing the free and independent press citizens in a democracy need, and the Next New Thing to invest millions in will fix the problem. Bottom line: Journalism that serves the people needs the support of the people. That's the Next New Thing.

And it's what MoJo and our community of readers have been doing for 47 years now.

But staying afloat is harder than ever.

In "This Is Not a Crisis. It's The New Normal," we explain, as matter-of-factly as we can, what exactly our finances look like, why this moment is particularly urgent, and how we can best communicate that without screaming OMG PLEASE HELP over and over. We also touch on our history and how our nonprofit model makes Mother Jones different than most of the news out there: Letting us go deep, focus on underreported beats, and bring unique perspectives to the day's news.

You're here for reporting like that, not fundraising, but one cannot exist without the other, and it's vitally important that we hit our intimidating $390,000 number in online donations by June 30.

And we hope you might consider pitching in before moving on to whatever it is you're about to do next. It's going to be a nail-biter, and we really need to see donations from this specific ask coming in strong if we're going to get there.

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate