The chart above shows the correlation between chocolate consumption (per annum, per capita) and the number of Nobel Prize laureates per capita, by nation. It seems to show a very strong connection between the two. According to the author of the study, Franz Messerli of Columbia University,

“When you correlate the two – the chocolate consumption with the number of Nobel prize laureates per capita – there is an incredibly close relationship,” he says.

“This correlation has a ‘P value’ of 0.0001. This means there is a less than one-in-10,000 probability that this correlation is simply down to chance.”

But the author is trying to make a point about the use (and abuse) of statistics:

It might surprise you that we are trying to make a serious point. This is a classic case where correlation, however strong, does not mean causation.

Messerli gave us another example. In post-war Germany…