Editing Leon Festinger (section)

===Proximity effect===
Festinger, Stanley Schachter, and Kurt Back examined the choice of friends among college students living in married student housing at MIT. The team showed that the formation of ties was predicted by [[propinquity]], the physical proximity between where students lived, and not just by similar tastes or beliefs as conventional wisdom assumed. In other words, people simply tend to befriend their neighbors. They also found that functional distance predicted social ties as well. For example, in a two-storey apartment building, people living on the lower floor next to a stairway are functionally closer to upper-floor residents than are others living on the same lower floor. The lower-floor residents near the stairs are more likely than their lower-floor neighbors to befriend those living on the upper floor. Festinger and his collaborators viewed these findings as evidence that friendships often develop based on passive contacts (e.g., brief meetings made as a result of going to and from home within the student housing community) and that such passive contacts are more likely to occur given closer physical and functional distance between people.<ref>Festinger, Schachter, & Beck, 1950</ref>