Let’s expound the cultural differences first from their respective fairy tales and fairy tale character.
The most common hero of Russian fairy tales is Emelya, who sits on the stove and wants everything to go to him at the behest of the pike. Or Ivan the Fool, who has a father-tsar and does not understand what.
In Belarusian folk tales, the hero is the hardworking and courageous Yanka. The idler in Belarusian fairy tales is ridiculed, children are taught that the real hero is the one who works long and hard, despite the blows of fate.
Belarusians are Balto-Slayans who have their own national Slavic Belarusian language, which has many similar words with the Ukrainian language and the national language of Belarusians differs from Russian.
Russian does not understand when Belarusians speak their national language, Belarusians can be understood by Ukrainians, and Belarusians can understand Ukrainians, but not Russians.
Thus, Belarusians and Russians have a different culture, different history, different genetics, different mentality, different IQ, different languages, different interests. Belarusians and Russians are two completely different and alien peoples, Russians are not brothers and relatives to Belarusians.
Russians and Belarusians are both Eastern Slavs, including Ukrainians (and are therefore descendents of Old Russians), and Poles are Western Slavs who neighbour them. They are all Slavs and on a continuum with each other.
Fundamentally, these are all Slavs and share a fundamental culture. However, they are also distinct groups of Slavs with slightly different culture which has emerged over the last milenium and a half, and there are distinct sub-groups of many Slavic sub-groups as well.
The modern legal system of the Republic of Belarus belongs to the Romano-German (Roman-Germanic) Law family. The main characteristics of the Romano-Germany Law Family are rule of law, dividing law into public and private one, separating one branch of law from another.
