Both times I was in college (undergraduate and master's degree), it seemed like at least 90% of my professors were immigrants from foreign countries. I never r

Both times I was in college (undergraduate and master's degree), it seemed like at least 90% of my professors were immigrants from foreign countries. I never really thought to ask, but I would have assumed that they attended a foreign university in their home country at least for undergraduate... does this mean they all went to the same 8 institutions for a U.S.-generated PhD before they could move into academia?