Personality between Americans and Koreans

I have met some Americans so far. They were very active people and extroverted. But Korean are shy and calm. This is the difference of personality between Americans and Koreans. Americans communities can speak about everything but Korean communities can't. The person's personality is influenced by their country environment. For example, there was difference of class's atmosphere. In the U.S., many students speak their own voices in the class and participate freely because they think the teacher and students are equal and they respect opinions each other. On the other hand, In Korea, there is not an atmosphere of freedom in the class. As time goes by, Korea also intend to change from quite to active. However, Korean students are still quite in the class.