News reports about scientific research rarely distinguish between cause and correlation. Actually many of the studies do no better themselves. I was reminded of this when I heard about the Duke University research that shows that smokers that drink coffee are less likely to get Parkinson’s disease.

In families affected by Parkinson’s disease, the people who smoked cigarettes and drank a lot of coffee were less likely to develop the disease, say researchers at Duke University Medical Center.

They go on to say that:

The biological mechanisms through which smoking and caffeine might work in individuals at risk of Parkinson’s disease are still not clear, said study co-investigator Mark A. Stacy, M.D., associate professor of medicine and director of the Duke Movement Disorders Center.

I’m betting on pure correlation, that is, people with a predisposition to develop Parkinson’s disease are less likely to take up smoking or coffee consumption. I doubt smoking and/or coffee actually protects but, once again, time will tell. There is probably a bias named after this… Causation Bias or maybe Correlation Blindness Bias. Maybe I-Gotta-Make-This-Headline-Interesting Bias.