Why do we assume that attractive people are stupid?

Researchers plumbing the data in the National Longitudinal Study of Adolescent Health have found that, to some small yet statistically significant degree, good looks and intelligence go together. There’s even a correlation between being well-groomed and earning better grades. Which makes our question all the more perplexing: If spending time under a hair-drier is good for the brain, why are we so quick to assume that Daphnes are ditzes?

The big Adolescent Health study may suggest an explanation or two. For example, young people who are more attractive are also more likely to indulge in binge drinking. Which has a certain raw logic to it: The handsome and the pretty get invited to more parties. Perhaps our perception of their relative intelligence has something to do with the damage they suffer socializing.

But maybe the best explanation for the Velma-Daphne paradigm can be found in rational choice theory, as opposed to evolutionary biology. There are many ways to pursue the good things in life. Cultivating one’s intelligence is hard, requiring huge investments of time and effort. If you’re born with the rare and valuable asset, beauty, an asset that can be exploited rather more immediately than smarts (what with all the opportunity costs of education), it would make sense to make the most of said asset. Which is to say, for the attractive it just might be smart to be dumb.