I personally don't think there's a significant difference between Russians and Americans. They are genetically quite similar, only Russians have generally less money. Give a Russian woman of the same intelligence the same amount of money the average American woman has, and she'll spend it just as happily. She'll also be just as arrogant if that's what she feels like. Same goes about men in general. What you're seeing is more of a result of a political and economical difference than anything else. I could argue that the higher rate of comfort causes people's behavior to drift towards what can currently be observed in the West. The less dangers there are, be it poverty or war or diseases, the more people end up being the way they are in the US and the likes. It is also something that can happen fast, in just a few decades.