Do they study in groups with other people in the same class? If so, maybe they're snubbing you. If not, they're not.
I
need absolute silence with no distractions to learn something efficiently. I think the last time I voluntarily studied something as part of a group was during p-chem in college. Other people were just an anchor ... slowing my progress through the stuff I knew well, and rarely able to help me learn something I didn't. Actually, even having my wife or kids around me when I'm trying to study is intolerable - even if they're silently reading a book - and I like them a hell of a lot more than I ever liked any of my classmates.
This is just anecdotal, but the further I get in my education (currently in residency), I find a higher and higher percentage of people are solitary learners. If they didn't start out that way, they sure are now. Study groups were the norm in high school and college. They were fairly common in medical school. Nobody really studies during their intern year, so that year's moot. And now, I don't think I've ever seen two residents get together to study for something. I sometimes see our board-eligible graduates get together to practice for oral boards, but that is specifically something that involves interacting with another person.
That "medicine is lifelong learning" saying is absolutely true, and you simply
must acquire the ability to efficiently learn things on your own. So here's my opinion: study groups are a crutch ... often inefficient timewasters or social events ... and the sooner you ditch them entirely the better off you'll be.
Naturally, YMMV.