It’s been shown that we can roughly evaluate a man’s intelligence with a single glance at his face. This ability must provide an advantage, or we wouldn’t have developed it. It could be related to threat detection, perhaps. I can’t think of another reason.
The same is not true for women’s faces, however. All else being equal, then, perhaps a stupid woman is neither more nor less dangerous than a smart one.
Whereas for men — but which is the greater threat in a man, intelligence or stupidity?