The pigmaili effect is a kind of self-fulfilling prophecy. A person expects or predicts an outcome and subconsciously aligns their behaviors to meet that expected outcome simply because they believe it has to come true. The teachers in the pigmaili in the classroom study believe that certain students would perform better and inadvertently willed this outcome into existence with their teaching strategies. If teachers were told that a cohort of students would underperform, they likely would have subconsciously devoted less attention to these students,. It seems real obvious, but it's just across the board.