> I've heard people refer to "Moscow face" (though oddly, not "New York face"), where people's expressions are blandly neutral, tending towards negative - it's a way of adjusting to living in a large urban center.

There is a cultural aspect here though as well, many Russians only smile amongst people they know, they think that people who smile at strangers are either simple or up to something, I once asked a Russian about this and he said that you pretty much never smile except with friends and it's a different kind of smile, he also said it was one of the things he liked about England in that we are fairly close to Russians in that regard.

http://www.russianlife.com/blog/why-dont-russians-smile/