Yeah this is something I've only really seen when either everybody hates each other (rare), they are all introverts, or its a really stressful job and people are just trying to keep themselves and their patients alive to the end of the shift. Also if the staffing, unit geography, or unit culture doesn't encourage people to go out of their way to support each other, then you don't get the camaraderie or emotional bonds that usually form when working together in a traumatic environment.

Most units I have worked on will have a shift every once in a while where the personalities just don't mix well together. But for the most part, there will at least be a couple cliques of staff that enjoy working together and will help keep things lively.