The Pygmalion Effect: an invisible nudge towards success

Incredibly, the OP argues in favor of "wishing people smart makes them smart" by citing a famous example of a fraud! It conflates expectations of behavior influencing people who want to confirm, with expectation of success creating success.

As with most psych studies, there's probably a grain of truth -- of course investing in people tends to make them more successful, but it's not simple magic tricks.