Pygmalion effect: how do we affect people around us?

Have you ever heard of the idea that our thoughts determine our reality? Some agree with this, while others don't. When we talk about our own expectations from other people, these expectations can determine people's behavior. As a result, it can lead to the fact that we are finally convinced of our assumptions.
This is what the Pygmalion effect, also known as the Rosenthal effect, speaks of.

Rebecca Curtis and Kim Miller illustrated this by conducting the following experiment.
A group of college students, none of whom knew each other, were paired up. One person in each pair, chosen at random, received special information: some students in the pair were told that they were liked by their partner, and some were told that they weren't.

The pairs of students were then given the opportunity to meet and talk to each other. As it was predicted, those students who thought that their partner liked them, behaved more agreeably towards their partner; they were more open, expressed less disagreement on the topics discussed, and generally had a more cordial and pleasant manner of communication than students who thought their partner did not like them. Moreover, those who thought their partner liked them, actually were liked much more than those who thought their partner disliked them.

It turns out, our expectations really do affect how other people behave towards us. A person may mistakenly think that they are disliked, and behave embittered because of this. This will cause a negative attitude towards the person, even if others were initially positive in relation to them.

So, why not try to behave with people you want to please as if it already is?