Correlation does not imply causation means that if we find a high rate of cancer in a group of individuals with something in common that does NOT mean that common thing caused the cancer. We still need to find the cause of cancer. Examples of the logical fallacy show positive correlations of the diagnosis of autism and the rate of organic food sales, and a negative correlation between national murder rates and the spread of Microsoft’s Internet Explorer software. The point is the cause is not the correlation but some other mechanism needs to be found to explain and prove a cause.
In the case of radon and smoking there are lots of very definitive declarations of the cause of cancer. Simply everywhere we hear that smoking causes cancer and radon causes cancer. Even that radon plus smoking causes even more cancer.
So I checked it out.
I live in New England which is has the highest radon levels but the lowest lung cancer rates. So how can we reconcile this conflicting information?