The group even boasts an ambassador. When we run, we talk about current events, about sex, and of course about food. Naturally, many of my co-runners run for the same reason I do, to support an eating habit. We tell jokes and laugh at each others' witticisms. When running, employment, education, or social status is not primary consideration for selection of running partners.
Pace is the primary determinant.
Other social interactions, parties, professional contacts, schools, do not allow a person to develop such a close personal relationship so quickly. A couple of weeks ago I met a young man running. I. Still, we teamed up because we both arrived late for the 12 mile run and neither of us knew the route. We ran and talked and talked. He discussed his relationship with his parents and his brothers.