Culture shock is defined as "a common psychological response to an unfamiliar culture [which] is characterized by disorientation, heightened anxiety, and more rarely by depressed or paranoid behavior." (1) Three groups of people are prone to culture shock - those outside of their own countries, those experiencing a very different culture within their own countries, and former ex-patriots who are now returning home.
There are also three phases of culture shock - euphoria, anxiety, and adjustment. Short-term visitors and people who are very new to a culture see the new culture as exotic and exciting, but have not really left home, yet. Many people who go to international, multicultural, or ethnic fairs or who eat at an ethnic restaurant of a group not their own also experience the first pleasant stage of culture shock.
The second stage is not nearly so pleasant. This usually strikes people who have been in the new culture for awhile, and who are planning to stay longer, but it can also affect those just encountering a new culture. The written and unwritten rules that work so well at home no longer work, and in some cases the new culture makes little or no sense. At worst, people in this second stage see the new culture as a disaster and their own home cultures as ideal and they may experience much anxiety and even paranoia during this time.
People who stay in a new culture long enough and who learn enough of this culture's rules and logic usually adjust. This is the third stage of culture shock. By this time, the sojourner can see the merits and demerits of both the new culture and his home culture.
How Cultures Clash - Experts Count the Ways
Many scholars and researchers have written on culture shock and clash over the years. One of the earliest and most important experts on this subject has been the cultural anthropologist, Edward Twitchell Hall. The main focus in four of his books, Beyond Culture