Needless to say, I got to thinking this morning. I concluded that I don't think the idea holds any water. In their lives, it made sense: certainly while I was a kid they didn't have friends that weren't also collegues. They were what they did, which made the people that they were most friendly with people like them. But now that they have more option, they do have friends who don't fit so neatly into the mold, though they are still intellectuals that do share certain characteristics.
But it certainly doesn't make sense here. The job I have, and I would suspect many jobs for people my age, are not so intensive that they define precisely how I spend my time. As such, I have plenty of (theoretical) opportunities to go out and meet other portions of society(in a metropolitain area of almost 2 million, no less). Furthermore, as my coworkers have the same freedom, they are also unlikely to use the workplace as a source of relationships extending beyond work.
Then there is the issue of timing and social location. Many of these guys have been living here for years. They may well be part of social networks that see no reason to expand. As a newcomer I do not have a similar network, but even so that does not mean I can form one with coworkers.
How, then, to form groups? By interest and location. Location is the old standby, and also where workplace friendships arise from: time in similar environments polarises feelings between people.
((Ran out of time to finish this at work, expect me to finish the thought later tonight))