Arecent survey found that 80 percent of high school students believed that they were above average on reading, writing, and math skills. given that only 50 percent of any group can be above average on any dimension, this is an example of

this is called the illusory bias

Explanation:

i dont think this needs much of an explanation as you have the definition/explanation there.

although, ill give you a little bit, its seen as a cultural phenomenon as its not seen as prevalent in places like east asia. in east asia you are more likely to get opposite results even.

it is most noticeable and studyable when it comes to a persons intelligence and/or academic performance but it can also occur to thinking ones personality traits are better than they really are.

other words for this include the superiority bias or above average effect