Why do folk songs of different nationalities show different national characteristics?

Folk songs of different nationalities clearly show different national characteristics, mainly in that folk songs of different nationalities have different singing languages, and the rhythm, melody, style, scale, mode and texture of tunes all produce national individuality. For example, Korean folk songs, on the one hand, are sung in Korean, and the music has the unique tone charm of Korean; On the other hand, it retains some inherent features of traditional music, such as using 6/8, 9/8, 12/8, 3/4, etc. The "long and short" rhythm of percussion instruments such as sticks and drums is sometimes reflected in the tune; Music is lyrical and has the style of dance music.