Don't Mistake Correlation for Causation

Let me preface this blog by saying that yes, I am blogging to procrastinate, and no, this blog has nothing to do with school or class readings.

So you've heard the saying "don't mistake correlation for causation," right? So between my undergraduate major (sociology), minor (psychology), and my grad school education, I've taken roughly 6 courses that somehow relate to research methods, and about half of them have been quantitative. Well, I have always enjoyed the various examples I've heard of not mistaking correlation for causation because they are almost always funny. Anyhow, after watching an episode of South Park, I've got a new example!

Here are three examples of mistaking correlation for causation. I'll let you guess which one is the example from South Park.

1) Someone is doing research on shark attacks and they make a discovery. An increase in shark attacks occurs when there is an increase in ice cream sales, and a shark attacks disappear entirely when ice cream sales are at their lowest point. What do we need to do to prevent shark attacks from happening? Clearly, we need to stop selling ice cream!!!

2) A researcher is studying crime in an urban area and thinks there may be a way to lower crime rates in the city. In this large urban area, there have been several murders over the past year, but in a suburban area not too far away, there has been only one murder in the past five years. The researcher also notices that the large urban area has roughly 30 churches while the suburban area has only one. Isn't it clear why there is so much crime in the urban city? The abundance of churches!!!

3) In a small town in Colorado, a law is passed that bans the selling of fast food, which means that the local KFC has closed down. Another law is passed allowing for the use of medicinal marijuana, and this medicinal marijuana store has opened in the place of the KFC. In this town, (unbeknownst to the local doctor) men are purposefully exposing themselves to radio waves to induce testicular cancer so they can get prescriptions for marijuana. Due to the alarming rate of testicular cancer in town, the doctor argues that the KFC must be reopened because they did not have a testicular cancer epidemic when there was a KFC in town.