Of course even quite clever people can occasionally say, write, or do stupid things. But that’s very different from imagining that stupidity is uniformly distributed across the IQ curve. If we assume that in the West IQ is approximately (albeit imperfectly) associated with educational attainment, the data tells us that lower-IQ people are far readier to believe statements for which all factual evidence is contrary (e.g. “the world is flat” or “Donald Trump is the greatest President in US history”). Lower IQ-people also have a higher rate of poor lifestyle choices such as eating junk food to excess and smoking, which leads to a far higher incidence of disease. Lower-IQ people are also (as many studies have shown) far more ready to conform to group norms, whatever they may be, than more intelligent people. So we can see that as a general rule a greater amount of self-harming is indeed highly correlated with IQ. The lower one’s IQ the worse the self-harm becomes, and the more easily one is manipulated by the unscrupulous. IPSOS/MORI polls of both Brexit voters (in the UK) and Trump voters (in the USA) revealed very clearly that they are in general older, far less educated, and far less healthy than the average citizen. Given that these people drag down the average values for such things, the IPSOS/MORI findings are very revealing.

Anyone who enjoys my articles here on Medium may be interested in my books Why Democracy Failed and The Praying Ape, both available from Amazon.