Correlation is not causation (what does this mean?)

All my life I have heard the phrase, “correlation is not causation.”

And like many, I had no clue what it meant.

But today, I use this phrase all the time. And boiled down, “correlation is not causation” means that just because two things correlate does not necessarily mean that one causes the other.

I find it is best to use examples to better explain this:

Every time my face breaks out with acne, the sun rises in the east. This scenario is 100% correlation. But we all know the sun rising does not cause my face breaking out.

Thus, correlation is not causation.

Here is another interesting example…

When Crisco was invented in 1911, scientists discovered atherosclerosis developed about a decade later. This is why we have this war on transfats today.

Statisticians have claimed that Crisco both correlated and caused heart disease. But there has never been a proper scientific study showing a causal link between trans fats and atherosclerosis. I have not seen a single study proving this causation (and I have been hunting one down for most of my adult life). Thus, correlation is not causation…

By the way, there is WAY more potential causal evidence that the introduction of chlorinated water into our water supply is more likely to have a direct link to heart disease.