Lais forgot to mention, with the exception of Izabel Goulart who would be on team Russia if using that description...
Marija V is too serious from my experiences with her too. She doesn't smile very often and is only friendly when she has to be or will get paid. Sad. Beauty and money are not everything honey.
It is true that the Brazilians are usually more friendly and chatty with strangers. It's their culture. Russians and Eastern Europeans usually enter the international catwalk at a younger age, where language may still pose as a huge barrier. There are always exceptions. Some Russians are really sweet and friendly. And I have a list of Brazilians who are not that approachable in real life when they are not being paid to be.

There are good and bad apples from all parts of the world.