It's tradition that Russian children must fight and kill their fathers for sexual possession of their mothers at age 18. They train up to that point to murder their fathers with their bare hands, and after that they are considered men. Violence is a rite of passage.
They arn't, they might seem violent but it's just that Slavs tend to life a shit life.
That's why you always see Slavs making everything humorous as they need to find something to make life more enjoyable
They live in a climate that is very very frozen and cold and most of their citizens are bears on unicycles. I think you would be a bit violent if everyday you tried to take a nice drive my the nearest frozen lake and you had to keep in mind to drive around the copious amounts of bear shit on the road.