for another example, consider friendship formation among couples in apartment buildings. In this particular case, residents had been assigned to their apartments at random as vacancies opened up, and nearly all of them were strangers when they moved in when asked to name their three closest friends in the entire housing project, 65%named friends in the same building. Among those living in the same building, compared to only 22% who lived two doors apart and only 10%who lived on the opposite ends of the hall.
Certain aspects of architectural design make it more likely that some people will come into contact with each other more often than with others, even though the physicai distance between them might be the same. This is known as functional distance. For example, more friendships are made with people on the same floor than on other floors,