I have long said that it’s important to study intelligence — IQ, cognitive ability, whatever you want to call it. For one thing, in a knowledge-based economy this trait powerfully affects where people end up in life, and you have to understand intelligence if you want to understand, say, economic mobility or inequality.


And the importance of studying IQ doesn’t magically stop at the borders of politics. Indeed, there’s a fair amount of research on whether more intelligent people tend to have different political views. Generally, they tend to be more socially liberal, but also economically libertarian in certain ways, such as opposing income redistribution and supporting free trade. Those of us with libertarian tendencies might say these are simply smart things to believe, but there are other explanations as well, including basic self-interest.

But we who write about IQ usually understand that it’s a fraught topic and should be handled with care, lest it devolve into simply calling people stupid, and I’m afraid a headline-writer over at Pacific Standard succumbed to that temptation in titling an article “Trump’s appeal to the cognitively challenged.”

The underlying academic study actually has some interesting stuff in it, though it’s limited in various ways. (E.g., it relies on a vocabulary test as a proxy for IQ.) One detail the Pacific Standard didn’t bother to note, for example, is that there was a far stronger link between low cognitive ability and support for Obama in 2012 (.166) than there was between low cognitive ability and support for Trump in 2016 (.08).


The headline results — in which low cognitive ability is a particularly powerful predictor of Trump support — don’t pop out until the researchers include a bunch of statistical controls. They control for race, for example, which affects the findings because “Black Americans, who tend to score lower on cognitive tests than White Americans, mostly vote Democrat.”


Is your smugness giving way to discomfort yet? This is why one should never gloat about the results of IQ tests. Ever.

And as Derek Cohen pointed out to me on Twitter, this chart speaks volumes about the appeal of Trump:

But go ahead, call Trump supporters “cognitively challenged” and see where that gets you.