For a long time, my office was entirely white males aged 18-35. It grew to about 35 people or so over the years, during which time we picked up a 40 year-old white male, and a female. Both have since departed.
Being somewhat of a social outsider has had professional consequences. I get along with people at my office, and I have even liked on a personal level several employees that have come and gone. But when we'd do BBQs and people would drink ten to twelve beers and then drive home, I spoke up. And when people would grossly falsify their timecards and lie on expense reports, my boss didn't really have much interest, since he was doing it, too.
We have a more serious manager and things have calmed down now (mostly), but I know that one reason I'll never be promoted here is because I'm on the outside.
I don't think I want to fit in.