Why does praising children's intelligence cause them to give up, while praising girls' looks causes them to put effort into the looks?

is not isomorphic to "praising x will cause less x and praising y will cause more y". Praising intelligence causes kids to emphasize intelligence and de-emphasize competing explanations, e.g. hard work. Praising looks causes kids to emphasize looks and de-emphasize competing (for time) qualities, e.g. knowledge. In both cases praising x causes more x, and also less other stuff because of opportunity cost.