98% of our year freely share their marks around; sometimes someone would get a really bad mark and rather keep it to themselves, which of course is perfectly understandable. What I do not understand however, is those who get competitive by keeping ideas to themselves in class.
We were having a discussion about Othello in English Advanced and just pouring out streams of consciousness in an attempt to get ideas for the upcoming assessment task. This one guy, let's call him X (he was a pretty good guy in year 10, but he's been getting cocky lately), then gets a good idea, whispers it to a mate (we'll call him Y) who tells him it's excellent and to tell the class (or confirm the idea with the teacher, I don't know for certain) and he says, "But everyone else will hear it!" Then, half the class turns to him and just goes "What the hell X, we're trying to help each other here!" But he just shrugs it off with a smirk.