Yeah that's interesting, I'm in one of those large complexes -- advantage from an #urbanism perspective that I'm very close to lots of mass transit and "car free" living options, etc.
But it's not a very "social" place, and it could be more so. I use the common areas frequently, despite a bit of "tragedy of commons" maintenance situation, because (a) I want to take advantage of them and (b) I want to Be the Change in terms of being more visibly social.
Group activities are a great start. Game nights, etc...