Children who immigrate to the United States have similar experience to MKs when it comes to learning a new culture and making cross-cultural transitions. But according to Pollack and Van Reken, what truly distinguishes MKs from children who immigrate to the United States or other countries is "the full expectation that after living for a significant period of their developmental years outside their passport culture, there will come the day when TCKs make a permanent return to that country and culture."[6] MKs return to their passport country for many reasons, including the beginning of their college education, a shift in their parents' career, and even evacuation in more extreme cases.