Festinger, L., Schachter, S., Back, K., The Spatial Ecology of Group Formation, In L. Festinger, S. Schachter, & K. Back (eds.), Social Pressure in Informal Groups, 1950. Chapter 4.

Paper on ecological determinants of friendship and group formation.

Study on two housing projects, Westgate and Westgate West, probability of friendship is inversely proportional to the living distance between people. People will have passive contacts leading to nodding actuantanceships, speaking relationships, and finally into friendships.

The authors surveyed the two housing projects, asking which three people the most associated with in the two projects. Then they normalized the distance between all the apartments They found that most of the friendships arose between neighbors, especially looking at one floor. People on different floors had a similar but less sloping relationship.

Between buildings, the relationship also held true, although the absolute numbers were much smaller.

Also, those people living near pathways to and from buildings also had a greater chance of meeting people and thus building friendships. Thus one must be careful to note physical and functional distances.

It appears the housing projects are for students.