If we're to adopt TRP theory about attractiveness, then we assume that the most attractive women are those who are endowed with beauty, youth and fertility and that the most attractive men are those with looks, height and status.

By this standard, intelligence is inherently unattractive, as most women seem to go gaga for men who're unintelligent. They fawn over jailbirds, many of whom are functionally illiterate. They go for the football team, even though most of them are stupid.