American college dormitory living is fairly unique. Students at European colleges live mostly off-campus, and find the idea of sharing a bedroom with a stranger to be odd. The system we have has evolved over the course of more than 300 years, beginning from an initial philosophy of togetherness.
In the colonial period, college buildings were often single, multipurpose structures that housed all the functions of a school, including the president’s home, faculty apartments, student bedrooms, chapel, library, dining hall, and classrooms. Harvard’s first governing board reported in 1671, “It is well known … what advantage to Learning accrues by the multitude of persons cohabiting for scholasticall communion, whereby to acuate the minds of one another, and other waies to promote the ends of a Colledge-Society.” Since the actual curriculum was limited, Christian morality was a large part of what boys absorbed at the colonial college. This character formation was gained by observing role models; professors and students sharing living space was good for moral development. This attitude was an essential intellectual and emotional precondition for the American dormitory.
One can only imagine how that arrangement stifled faculty lives and inhibited recruiting. As more students went for higher education, colleges sprouted fraternity houses, then dormitories to compete with them, then special facilities for women. All that time, the philosophy of bringing students together strained against the philosophy of keeping them apart. Read the history of American college dormitories at Smithsonian.