The third classroom experiment returns to an exercise that I posted about on 6 March, at the start of semester. At the end of an introductory quiz, I asked the class:
Looking around the classroom, what percentile of the relative distribution do you expect to end up? For example, 100 means you expect to top the class, 75 means you expect to outperform 75% of the class. 50 means you expect to be at the middle of the distribution, 25 means you expect to outperform 25% of the class. 1 means that you expect to be at the bottom of the distribution.
My March post dealt with the fact that there was a rather strong ‘Lake Wobegon Effect’ in the data, with no student saying that they expected to end up below the 50th percentile. Now that we have the final grades, we can ask the question: how well did students predict their relative rank? Below is the relationship between students’ predicted percentile in the distribution (horizontal axis), and their actual percentile (vertical axis). If all students correctly predicted their rank in the class, all the dots should line up along the red line. By contrast, the green line shows the fitted relationship. Students who rated themselves more highly did in fact do a smidgin better, but the relationship is very weak.
Now, here’s what happens when I break the sample into male and female students.
It seems that female students were substantially better at predicting their relative rank than male students. Does anyone know of psychological theories that are consistent with this?