[RooldpalApata]

I've always been Class conscious; so social class is very important and "cultural tastes" are part of this affiliation (as Bourdieu said).

Language is important but only in countries, or cultural spheres where it is an issue. In homogenous countries, language is not that important.

Race; while important, is less so than social class or cultural differences.

Then you have psychological profile... people tend to gather with other people with the same level of introverson/extraversion.