Which would not be one reason why the self fulling prophecy was not demonstrated at higher grade levels

The correct answer to this open question is the following.

Although you did not include a specific case, context, or further references, we can comment on the following.

You neither attached options to answer the question.

In general terms, the self-fulling prophecy was not demonstrated at higher grade levels because the higher the education level of people, the less inclined are to believe in superstitions or the less inclined to allow popular myths to be part of their reality.

Let's have in mind that a self-fulfilling prophecy happens the moment people accept false beliefs as real and their minds focus on those ideas to the degree they can become real.

High-educated people, true professionals focus instead on hard work, determination, preparation, and tenacity to make their dreams come true.