Oct 03, 2009 in Public Health
Photo by Andres Rueda
The steady decrease in pirates and the increase in global warming over the last few centuries are strongly correlated (i.e. they appear to change at related rates). However, does this imply that pirates were preventing global warming? What about foreign lemon imports and autism rates? Has the increase in US lemon imports contributed to the increase in autism rates? Undoubtedly, these examples seem silly and unlikely, but knowing why requires an understanding of the difference between correlation and causation. The following video (broken up in to two parts) summarizes these differences quite nicely.
Disclaimer: In no way do I mean to downplay the gravity of autism. With an incidence rate now estimated around 1 in 150, it inflicts a heavy burden on our families, friends, and communities. However, this makes it even more important to maintain a high degree of discretion when it comes to searching for a cause and a cure. Witch-burnings (e.g. the anti-vaccine movement) fueled by emotion and backed by poor evidence will only lead to dead ends and serve to slow down the progress of real scientific discovery.