Do studies show weed cause strokes and heart attacks? No.

A widely cited study about marijuana use commits so many egregious statistical errors that it's a poster child for junk science.

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Thirty years ago, the sociologist Craig Reinarman observed that there's something "woven into the very fabric of American culture" that makes us susceptible to believing that a "chemical boogeyman" is to blame for "society's ills." He added that every moral panic about drugs since the 19th century has been fueled by "media magnification" in which the danger of a particular substance is dramatized and distorted.

Now that recreational marijuana is legal in about half of U.S. states, and more Americans are consuming weed than ever before, the chemical bogeyman is back, and he's armed with a new paper in the Journal of the American Heart Association by researchers from Harvard and the University of California, San Francisco.

This study, which was amplified in The New York Times and The Washington Post, commits so many egregious statistical errors that it's a poster child for junk science. The paper would be comical if it didn't offer bad medical advice. The researchers did almost everything wrong.

Which is not to say that the authors committed fraud or misconduct. In fact, they did exactly what Ph.D. students are taught to do, what journal editors look for, what referees approve, what universities reward, and what granting agencies fund. Because the paper uses conventional methods to arrive at false conclusions, it speaks to the profound crisis in academic research.

We've forgotten that the point of scientific studies isn't seeking the approval of institutions. It's the pursuit of truth.

Motion Graphics: Adani Samat & Regan McDaniel

Audio Production: Ian Keyser