Sociology at work

I found myself thinking sociology when I was at work last weekend. At work we all usually get along great but lately there's one girl who's been getting on everyone's nerves it seems. When we would all get together to talk everyone would laugh at something I had said, or something another girl had said, but when the 'annoying' girl would say something similar she was instantly shut down or out of the conversation. I didn't get why everyone was doing this and when I asked one of my co-workers later he said that it was because she was 'just weird' now. It was a perfect  portrayal of social conflict as things she said were not heard anymore because her social status had been demoted to something lower than everyone else's. I think it's strange that that happens all the time in school, and to be honest I sometimes am at fault in the situation, but we don't really do anything to stop it from happening.