The third section of the article titled "3. The instrumental role of task difficulty." goes into how "people misperceive how hard the task is across the populat

The third section of the article titled "3. The instrumental role of task difficulty." goes into how "people misperceive how hard the task is across the population" based on task difficulty, and quotes a good amount of research that shows this is true. It seems pretty intuitive why people would use task difficulty as a heuristic for relative performance.