Messerli 1 suggests that, because chocolate contains flavonoids shown to improve cognitive function, we might expect to see a correlation between a country's chocolate consumption per capita and the number of Nobel laureates that countries produce. Indeed, Messerli revels in the strength of the correlation between these two variables. However, the study seems flakey to us, since the use of large-scale correlations with cultural data is a rocky road, and it can too easy to fudge the difference

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... tween cause and correlation. We present some data that mars the previous inference. Our present study aimed to show how Messerli's study is problematic on several fronts. First, there are no controls for why certain countries might have differential levels of chocolate consumption. For instance, patterns of chocolate consumption are higher in winter than in other seasons 2 , suggesting that countries with colder climates will consume more chocolate. Second, by looking at IQ instead of Nobel laureates, we offer a more suitable proxy for investigating possible population-level effects. This is especially true considering that Nobel laureates constitute an extreme outlier and will likely introduce a large amount of systematic error. Third, the correlations we find here might be artefacts of the degree of industrialisation and levels of spending in education. We therefore also controlled for GDP-a general indicator of a country's wealth and a coarse proxy for the amount of money invested in education.