I would guess that being a valedictorian is not so much a sign of being smart but of obedience. Certain subjects like history require rote memorization rather than intellect/understanding. That's why the intelligent anti-social folk tend to do good at subjects like mathematics yet could care less about subjects that are testing pure memorization.

I honestly think that having As in subjects that don't matter much, shows a form of mental illness like OCD or a lack of self-identity. It may be a grim and rather crass outlook so if you have a counter-example, I'd love to hear it.