They all tend to hang together but I notice that most of the interactions are with there own.Remember though a locality vartiant is only that you might have 1 species and 6 localities(not recomended if you plan to breed them).The incisus males display and confront each other and the same with the lacustris they ignore the other rainbows in the tank thats not to say they wont crossbreed.I kept rainbows(1 type) in a 5000ltr pond and they definately schooled as they had the room to get away from each other but chose to swim around in either 1 or 2 groups.I think most tanks are not big enough to see true schooling behaviour.