Russians are wired differently than westerners
That sounds awfully deterministic and it could be downright dangerous if someone takes it as a given or uses it as propaganda. Just plug in a different nationality or religious group and you'll find plenty of people who would take offense. I don't buy it, as even the term "westerners" or "easterners" is a social construct after all. That's not to say that people across the world don't have really different outward dispositions at first glance. But I think they are a product of culture and the social ties and interactions they have with others more than any hard wiring. That's what shapes their thinking, attitude and outlook. Of course some things about any given person are a product of genes, but I don't know how behaviors and outlook could be hardwired since behaviors and norms are passed down and learned (one is not born with them). Repetition, habit, and reinforcement from peers is more effective at shaping behavior, and people do adapt when they're placed in a different culture and environment. And they take things from other cultures they happen to intermix with.
There are some countries in the world that are more monolithic than others, including the one I grew up in, and that helps explain a lot of things including feelings about other nationalities or race or general outlook. Russia, by virtue of its huge size, history, physical isolation in many spots, patterns of travel and trade (economics), political and social system, and relationship with other countries is really complicated. I think it takes a lot of deep study and understanding to try to really know and understand someone whose culture appears dissimilar to your own (I bet a Serb or Bulgarian or even Greek could understand a Russian better than anyone here). It's really easy and intellectually lazy to apply different labels only because there are easy contrasts to be found on the surface (warm vs cold, outgoing vs reserved, etc.). The "dour" and "sad" comment was an example of an oversimplified heuristic (in my view at least). It sounds like merely a juxtaposition of what we think of ourselves (the opposite of course), which is also not objective. This whole thread is more like a popularity contest of sorts, not particularly meaningful but a way to find "people just like me" or "having traits that I like" but as defined by my own culture as primary characteristics, of course.
For the record, I think there are all sorts of people (along the full spectrum) in any country, but people just "click" with others who are more like them or whose characteristics they like best. As Anthony Bourdain said, people are the same everywhere and share the same hopes and dreams as anyone else - they're more similar than different.