At most universities, athletes are placed together. At Ivy League schools, it can vary as with any other universities. Sometimes if you are an incoming freshman, they try to place you with other freshman athletes if that is your preference. It is a mix; you may be paired with an athlete or a regular student. Usually, at Ivy leagues, they try to diversify all student accommodations so that you are a part of a big group and not just within the same category of athletes.