When I was heading to Harvard a hundred years ago, my best friend from high school was heading to Princeton. He received in the mail a special "freshman pre-registration issue" of the Daily Princetonian. It offered incoming freshmen the following advice: "Be sure to bring all your high school debate trophies, varsity letters, certificates of commendation, etc. We have a big bonfire during Freshman Week, and you can throw all that crap in there then."
Everybody's high school GPA was fine; no one talked about that, ever. My girlfriend once told me that she didn't have the best grades in her high school class, and that was 100% of what I knew about people's high school grades, except for people I had gone to high school with. No one talked about their college grades, either. I knew people had great grades if they made junior Phi Beta Kappa (that's how I found out my girlfriend and my roommate had great grades; I had never discussed grades with either of them), and then at graduation you found out who got summa, magna, etc.
Same with test scores. Everyone had done fine. End of discussion.
I've been in one or two discussions where people talked about test scores. But it's a rare event.
As for college grades, you might talk about a specific exam, paper, or even class, but it's rare for people to talk about cumulative GPA or any broader measure of performance. I know the GPA of a few very close friends. But that's it.
You know how if a student is in the same class before you and they have a test, many of his/her classmates ask her what is on the test? Do Yale, or any other Ivy League college students for that matter, do that often or is everyone just super-competitive with one another?
In college, most everyone takes exams simultaneously. It's not as if 1st hour Calc students could help 3rd hour Calc students. That's not how college classes are run. People are not super competitive in general. Very self driven, but very little jockeying against other students.