"Ethnic diversity is increasing in most advanced countries, driven mostly by sharp increases in
immigration. In the long run immigration and diversity are likely to have important cultural,
economic, fiscal, and developmental benefits. In the short run, however, immigration and ethnic
diversity tend to reduce social solidarity and social capital. New evidence from the US suggests
that in ethnically diverse neighbourhoods residents of all races tend to ‘hunker down’. Trust
(even of one’s own race) is lower, altruism and community cooperation rarer, friends fewer. In
the long run, however, successful immigrant societies have overcome such fragmentation by
creating new, cross-cutting forms of social solidarity and more encompassing identities. Illustra-
tions of becoming comfortable with diversity are drawn from the US military, religious institu-
tions, and earlier waves of American immigration."