Pet Peeve: Correlation is not cause!

Someone hit one of my pet peeve buttons in a meeting today. That particular pet peeve happens to be the confusion between correlation and cause. Just because two things are related or associated does not mean that one caused the other.

My favorite example from college goes like this…

In the summer, we see crime rates increase at the same rate that ice cream sales also increase. Therefore, crime and ice cream are associated or related. There is a correlation. But does ice cream cause crime? Are people who eat ice cream more likely to commit crimes? No. There is no causal relationship between crime and ice cream.

So the next time you read some report asserting that marijuana use is associated with low IQ or some other such malady, do not fall into the guilt-by-association trap and repeat after me…

Correlation is not cause… Correlation is not cause…



Categories: Research, Stats, War on Drugs

Tags: , , , ,

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