My high school was super chill. There were standard groups such as jocks/nerds/etc. but lots of people would also move from one group to the other. There were even semi regular out-of-school events that involved people from all groups.

I'm sure there was some bullying going on, but based upon my observations it didn't seem widespread. Of course I was a teenager and probably not the most observant person and may have had a skewed view of the average person's experience there.