"Kids who are praised for intelligence over effort have been shown in some studies to pick easier problems and give up quickly if a problem is too hard"

You're implying that praise for intelligence makes people lazy. But if they weren't lazy, then they would likely be praised for effort - it's at least as plausible the causality goes the other way.

Claimed evidence makes me think of the regression to the mean paradox/fallacy, where people predictably do worse after praise and better after criticism.