Final answer:
Studies of friendships in dormitories show that people form close relationships with those they have regular contact with, rather than based on physical attractiveness or shared interests.
Step-by-step explanation:
The surprising effect observed in studies of friendships in dormitories is that people are more likely to form close relationships with people they have regular contact with, rather than factors like physical attractiveness or shared interests. Proximity plays a crucial role in friendship formation as it provides the opportunity to get to know someone. This research suggests that the most influential factor in determining with whom you become friends is the people with whom you have the most contact.