The interaction between 5C students depends largely on the individual students. Students who are involved with lots of clubs and 5C students or who are outgoing at things like parties know students from all 5Cs. I personally only know one Mudder and I met him through debate. My friends who play sports know many people from the other schools through their teams. You can go to a Claremont College and only know people from your own school or know more people from a different school, depending on what sort of activities you join. The 5Cs do not interact as much as advertised on a regular basis but the students who want to interact definitely can.