What underlying cause often leads to a student's poor academic performance when they are labeled as 'low achievers' by their teachers?

When teachers call a student a “low achiever,” they often lower their expectations and give less encouragement, which makes the student feel less capable and less motivated. This lowered confidence reduces the effort the student puts in, and the weaker performance confirms the teacher’s belief. The cycle of expectation, effort, and outcome feeds back, creating a self‑fulfilling prophecy. For example, a student who receives fewer challenging assignments may not practice the skills needed, so their grades fall, reinforcing the teacher’s label. Thus, the teacher’s initial low expectation is the underlying cause that drives the decline in performance.