Cultures are generally classified into two categories: folk culture and public culture. The former refers to a culture that emphasizes the personal relationships in settling affaires. In such a culture laws are eclipsed by custom and moral in the maintenance of social order. People pay even meticulous attention to the custom. Any break of the custom is considered as unacceptable as regicidal behavior or commitment of some felony. Thus when a visitor is in such a culture, it would be better for him or her to “Do As Romans Do When in Rome.” In a certain sense, to adopt the local custom is a way for an alien to survive.

　　“Public culture” is coined to refer an ethnic group whose social order is maintained by legal instruments, although custom is emphasized. But custom in such a culture seldom remains the same for a relatively long time. Under such circumstance, it is usually unnecessary for a visitor to calculatedly follow the natives’ custom. Even the new comer preserves all his or her own custom or culture, it is safe for the visitor to do whatever he or she wants to do provided it is legal.

　　Put it simply, in a public culture it is unnecessary to adopt the local new custom. But in a folk culture, to follow the local custom is a must.