False Cause

In plain terms

A false cause treats a connection between two things as proof that one caused the other. They happen together, or one follows the other, so the mind links them with an arrow: A caused B. But things can travel together for many reasons, and most of them aren't "one caused the other."

This is the broad family. Post hoc ("after this, therefore because of this") is its best-known member, the version that mistakes sequence for cause. False cause covers the wider error: mistaking any correlation for causation.

Why it's fallacious

Two things can correlate because A causes B, because B causes A, because a third thing C causes both, or because the pattern is pure coincidence. Spotting a correlation tells you a relationship exists; it doesn't tell you which of those four it is. Jumping straight to "A causes B" picks one explanation out of several without ruling out the others, and usually picks the one that fits the story you already had.

Ice cream sales and drownings rise together. Ice cream doesn't cause drowning. Summer heat drives both. The correlation is real; the causal arrow is imaginary.

Canonical example

"Cities with more police officers have more crime. So adding police increases crime."

The correlation is probably real, and the causal conclusion is almost certainly backwards. Cities hire more police because they have more crime; the crime drives the staffing, not the reverse. The argument sees two things moving together and assumes the arrow points the convenient way, when reverse causation, or a shared cause like population size, explains the pattern better.

Counter-example (not a fallacy)

"Smoking causes lung cancer. The link holds across decades, dozens of independent studies, a clear biological mechanism, a dose-response relationship, and it survives controlling for other factors."

This isn't false cause. The causal claim rests on far more than correlation: a known mechanism, consistency across many studies, the fact that more smoking means more cancer, and the elimination of competing explanations. Establishing causation is legitimate when the evidence goes beyond "they move together." The fallacy is concluding cause from correlation alone.

The line: is there a mechanism and a ruling-out of other explanations, or just two things that happen to move together?

How to fix it

If you've been linked here, run the correlation through the other possibilities before settling on cause. Could the arrow point the other way? Could a third factor drive both? Could it be coincidence? The fix is to look for a mechanism (how would A actually produce B?) and to check whether the link survives once obvious confounders are accounted for. If all you have is that two things move together, the honest claim is "these are correlated," not "this causes that."

If you're on the receiving end, offer a rival explanation: "That might be reverse causation, or something else driving both. What rules those out?" A solid causal claim has an answer; a false cause usually doesn't.