The article “Chocolate Consumption, Cognitive Function, and Nobel Laureates” recently published in the New England Journal of Medicine (NEJM) demonstrates that even published research may contain errors.
The author, Franz H. Messerli, examines the correlation between countries’ chocolate consumption per capita and Nobel laureates per 10 million people. The linear relationship is strong, as shown in the article’s chart reproduced below:
Based on this result, the author concludes:
“However, since chocolate consumption has been documented to improve cognitive function, it seems most likely that in a dose-dependent way, chocolate intake provides abundant fertile ground needed for the sprouting of Nobel laureates.”
Stripping away the plant growing imagery from the quotation above, Dr. Messerli is quite simply asserting that chocolate consumption contributes to higher Nobel laureate counts per capita across countries. Below are the top five reasons why Dr. Messerli’s conclusions aren’t supported by his analysis:
- Improper order of cause and result
- Unlikely link between cause and result
- Failure to consider more likely explanations
- Failure to demonstrate that subjects received the “treatment” (i.e. increased chocolate consumption)
- Omission of several countries, including those with relationships in opposition to his conclusion
A more detailed discussion of the above five errors is described in this article.