Did you know that when Nicolas Cage appears in films, he causes people to drown in swimming pools? Here’s “proof”:

I’ll bet you also didn’t know that cheese consumption causes people to die by becoming tangled in their bedsheets, but the proof is plain to see:

These charts, by Tyler Vigen, are two of the many hilarious examples in his book, Spurious Correlations, that illustrate the maxim “correlation does not equal causation.” While the correlations illustrated are real, there is no causation involved.

It is a logical fallacy to equate correlation with causation, to assume that because A and B occur together, A causes B. In fact, there are three other possibilities: B may cause A; something different, C, may cause both A and B; or the correlation may be a complete coincidence. Discovering a correlation between two things can be a valuable first step in determining whether causation exists. (After all, causation does not exist without correlation.) But to assume causation exists is a fallacy.

Just because an argument is fallacious does not mean that politicians and others will not try to make it stick. When Rudy Giuliani was mayor of New York City in the 1990s, he ordered more arrests for minor offenses like graffiti, relying on the “Broken Windows” theory, which held that such arrests would help prevent more serious crimes from happening. In fact, crime did decrease overall in the city throughout his tenure. Giuliani claimed that his policy worked, and the statistics proved it: when arrests went up, crime went down. In reality, the drop in crime from the 1990s onward occurred nationwide, not just in New York City, and a number of different factors played a role in causing it. As for the two correlations illustrated above, I’m betting on coincidence.