Research confirms that a teacher's beliefs about a student's chances of success in school influence how that teacher acts toward that student, which, in turn, influences the student's achievement. If a teacher believes that a particular student cannot succeed, the teacher might unwittingly behave in ways that subvert that student's success—or at least do not facilitate that student's success.

Key ways that teachers—often unconsciously—communicate expectations to their students include their (1) affective tone (i.e., the extent to which the teacher establishes positive emotions in the classroom and reinforces cooperative behavior) and (2) quality of interactions with students (i.e., behaviors such as creating more output opportunities for high-expectancy students when answering questions or responding to learning tasks). As long as students receive differential treatment regarding affective tone and quality of interactions, a teacher is not providing fair and equitable learning opportunities for all students. Obviously, teachers must strive to exhibit equal behavior with high- and low-expectancy students.