Evidence suggests that the attitudes and expectations people bring into an environment can impact outcomes.
This is known as the Pygmalion Effect.
The Pygmalion Effect is a phenomenon where higher expectations lead to higher performance. Our beliefs in another person lead to our actions toward them. This influences their beliefs about themselves, which impacts their actions toward us, which in turn influences our beliefs about that person. Therefore, it is important to hold high expectations for anyone being supported by another.
Watch this short video to learn more about the Pygmalion Effect.