The Difference Between Correlation and Causation

The educational channel Sprouts explains the difference between correlation and causation, noting that one does not imply the other.

In statistics, we must differ between  correlation and causation. Correlation means two things move together  at the same time. Causation means one thing causes a change in the  other. 

The narrator observes that our brains like simple answers, but that often leads to errors in interpretation.

Our brains love simple stories, such as X causes Y. This is why when we see a strong correlation, say  kids’ shoe size and reading ability,  We may think of causation. But three  solutions help us avoid these errors.

The errors include confounding factors, reverse causality, and spurious correlation.

As kids grow, they need larger  shoe and get better at reading.  If a third factor drives correlating  results, we call it confounding. Then there is reversed causality. We may think that ice cream makes people happy,  but maybe happy people just have more reasons  to buy ice cream? … Spurious correlation exists when patterns appear  by chance. For example: as the number of pirates   decreased, we recorded increasingly hotter  days—but there’s no plausible common cause.

Lori Dorn
Lori Dorn

Lori is a Laughing Squid Contributing Editor based in New York City who has been writing blog posts for over a decade. She also enjoys making jewelry, playing guitar, taking photos and mixing craft cocktails.