Human's behavior depends on its upbringing. Russians are more open minded. And when you see gloomy faces in the public transport or on the streets it doesnt mean that all those people hate you. Is just they have their own problems which is projecting on their faces. They don't try to cover it under fake smile or put on a mask to play another role. They are what they are, that's it.

And of course the level of life influence on people's condition and their mood.