It comes as no surprise that America is growing more diverse. But some Americans might be surprised by the degree to which that diversity is dispersed.

Nearly half of Americans under age 20 are members of racial and ethnic minorities, a fact that someday will call into question the very use of the term minority. In nearly one-fourth of the nation's counties ... Hispanic, black, and Asian young people make up a majority. ...

Diversity fosters tolerance and understanding ... It also erodes the tendency toward groupthink. Like-minded people often reinforce — and indeed, exacerbate — one another's biases. The result, known as "incestuous amplification" in military circles, produces extreme thinking with large blind spots.

Ethnic diversity is not the only solution, but it is one of them, and a welcome one. America long has taken pride in being a melting pot. The latest Census figures show that the American stew is growing thicker — and, therefore, richer.