tyler butler

Correlation != Causation

Everyone repeat after me… Correlation does not imply causation! Just because two things can be proven to correlate does not guarantee a cause and effect relationship. Here’s a funny example from the Wikipedia article on the topic (courtesy The Simpsons):

Homer: Not a bear in sight. The “Bear Patrol” is working like a charm!

Lisa: That’s specious reasoning, Dad.

Homer: [uncomprehendingly] Thanks, honey.

Lisa: By your logic, I could claim that this rock keeps tigers away.

Homer: Hmm. How does it work?

Lisa: It doesn’t work. (pause) It’s just a stupid rock!

Homer: Uh-huh.

Lisa: But I don’t see any tigers around, do you?

Homer: (pause) Lisa, I want to buy your rock.

Please please please stop assuming that determining a cause and effect relationship is as straightforward as observing a correlation. It’s not.

Note: I know the != operator is not equivalent to “does not imply.” But I am too lazy right now to see if there’s even a Unicode character for the right symbol.