The Pygmalion Effect
Video:
https://www.youtube.com/watch?v=4aN5TbGW5JA
Wiki:
https://en.wikipedia.org/wiki/Pygmalion_effect
Rosenthal and Jacobson held that high expectations lead to better performance and low expectations lead to worse,[1|1] both effects leading to self-fulfilling prophecy. According to the Pygmalion effect, the targets of the expectations internalize their positive labels, and those with positive labels succeed accordingly; a similar process works in the opposite direction in the case of low expectations. The idea behind the Pygmalion effect is that increasing the leader's expectation of the follower's performance will result in better follower performance. Within sociology, the effect is often cited with regard to education and social class.
