Here is a study.
I think this is an excellent example of the misuse of statistics, not to mention purposeful blindness to confounds, unwarranted conclusions, and bias in every direction. The author makes extremely silly conclusions, such as, “The slope of the regression line allows us to estimate that it would take about 0.4 kg of chocolate per capita per year to increase the number of Nobel laureates in a given country by 1.” And this is just pulled out of thin air: “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.”
“most likely” my “ass.” I am sure the same “conclusions” can be made with Olympic gold medals, and we all know chocolate consumption and athletic performance must be positively correlated.
He even makes the suggestion that Sweden is biased in its selection. How about this: Alfred Nobel was Swedish and philanthropized his money to inspire generations of scientists. Sweden thus probably puts a lot of stock, not chocolate, into scientific education. Voilà! Strong science education is strongly correlated with strong scientific production.
And then what do you know! The news stories abound!