at my school all the selectives used to hang out with each other and then all the community kids hung out with each other.
then the white selective kids found the community kids and bonded
then some of the asians got rejected for not being asian enough and bonded with the white selective/community kids
then the curries realised that they could all hang out together and ditched quite a few of the asians they used to hang out with
now suddenly everyone's pretty friendly with each other overall, i think its due to in yr 11+12 there's no real "selective" ness anymore just the "smart class" and the "lower class" - "advanced/extension' and "standard" to divide us up. and trust me plenty of the selective kids are down in the "lower' classes.
so now we've all kind of merged, most of us talk to each other and stuff, but we still have our defined groups.
though i heard that in the senior area everyone just talks to everyone, but i dont hang out there so i wouldn't know.