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

I interpreted most of what you wrote as reflexive contrarianism with relatively little insight until I got to this part at the very end. Once you restated the claim in a very generic form "Praising X will induce more X, but praising Y will induce less Y" it called attention to the internal features of X and Y as being necessary to predict what will actually happen.

Once I understood the dichotomy here, I realized that I had no coherent theory about which trait-like surface features could be dropped in for X or Y to be suppressed or promoted by praise. My guess is that there's something that's actually pretty complicated going on here with cached selves, behaviorist conditioning, the fundamental attribution error, folk theories of human performance, and probably other stuff as well. I imagine I could have a somewhat evidence based working hypothesis for an answer 18 months from now if I keep my eyes and mind open but it seems clear to me that I don't have an answer of that quality right now.

Thank you for pushing forward in the face of downvoting. It was educational to discover a new puzzle in such a common situation :-)