Eating chocolate has made the Swiss smarter. Really?

I found an article that studies the beneficial effect of chocolate consumption on cognitive function. To prove his theory, the author uses the correlation between countries’ annual per capita chocolate consumption and the number of Nobel Laureates per 10 million people. And…nothing else.

Chocolate and Nobel Laureates

The study acknowledges some of its very obvious methodological limitations, but still concludes that “since chocolate consumption has been documented to improve cognitive function, it seems most likely that in a dose-dependent way, chocolate intake provides the abundant fertile ground needed for the sprouting of Nobel laureates.”

Now, for all we know the correlation is not “surprisingly powerful”, as the author concludes, but a mere coincidence. The many  non-sense correlation plots shared recently on social media have helped popularizing the idea that “correlation does not imply causation”.  The interesting fact about this article, however, is that it was published in the New England Journal of Medicine, one of the most prestigious medical journals in the world (featuring a staggering 54.42 (!!) impact factor). To be fair, the article is published as an “occasional note”, which also seems to serve as a humor section. If only all top-journals had such a twisted sense of humor!