Muhammad Ali [speaking in Zaire, Africa]: "There's no country as great as the smallest city in America. I mean [here in Zaire] you can't watch television. The water won't even run right. The toilets won't flush. The roads, the cars--there's nothing as great as America."
Group bias is the tendency to think more highly of one's nation, race, school, family, or other social group than is warranted by the evidence.
In saying, for example, that "there's no country as great as the smallest city in America," Ali is clearly overstating the comparative virtues of his own country, and thus is guilty of group bias.