I've seen girls gossip and act quite immature to one another in university. Yesterday while I was working on one of my research papers in the evening at campus, there were 3 girls having a pretty loud verbal fight over petty things, such as whining about clothing, about other girls and guys, etc... .

Sadly, in the first-year of university, it's still pretty much like high-school. This goes less and less as you get to the upper years although it still occurs there. One of the courses I'm in, a third-year biology course has us to dissections on numerous animals and we're pair ourselves into groups of four on the first day of labs and stick with that group. Unfortunately, one of the group members gets to be a bit gossipy but not too much. The group near us though is pretty much just noise with gossiping and sadly, it's a 3 hour lab (sometimes longer). It gets a bit irritating because you have to dissect very delicately when examining the individual muscles and separating them from others.

If you cant ignore it, then take it as a confidence-booster. If you have a high GPA, then they may not and so despite their bickering, you have something that matters a lot more: a high GPA and determination. You can also try to remember that you're going to pass the year and the courses while they may not. Also, you can take their criticisms of you as a reason to work harder.

If you're going to talk to them, you can either begin by some basic humour or just do your work and if you wish, try to in a discrete way, reveal a mark you got on a certain test, quiz, course, etc... if it's a high one. While it may not get them to stop gossiping, it may put you in a different light because now they may see you as a very intelligent person. You may work hard but they may have no idea that you do but once this is revealed, more people are going to want to be in a group with you because despite you being older, you're a lot more intelligent (i.e. higher GPA and marks) and that's what people want.

You can try to lead by example if you wish, however, I ignore gossiping people even when it's about me and simply let them fend for themselves with low marks. Once they realize it's not high-school and as the course gets harder, they're going to be more willing to go with you although their gossiping may still continue.