Since 1782, the Latin phrase E pluribus unum—“out of many, one”—has appeared on the Great Seal of the United States.

But what happens when we neglect and even deny the importance of the “one”—that is, cultural unity—and emphasize the importance of the “many”—that is, individuals—which, today, we call “diversity”? As a renowned social scientist learned, nothing good.

In his famous essay “Bowling Alone,” published some years ago, Robert Putnam documented our increased tendency to “go it alone,” instead of the civic participation that marked earlier eras. This decrease in “social capital,” Putnam argued, adversely affected American democracy.

Putnam’s latest project put contemporary ideas about “diversity” to the test and found them wanting. The data compiled from 30,000 interviews led him to conclude that “virtually all measures of civic health are lower in more diverse settings.”

The more diverse a community is, “the fewer people vote and the less they volunteer, the less they give to charity and work on community projects.” They “expect the worst from their community and its leaders.” In these communities, people don’t withdraw into ethnic and religious subgroups; they “withdraw even from [their] close friends” and “distrust their neighbors, regardless of the color of their skin.”

Instead of being engaged, they “huddle unhappily in front of the television,” what Putnam calls “hunkering down,” much like a turtle inside its shell.

Putnam’s findings stunned many observers: One political scientist said that “the extent of the effect is shocking.”

It is only “shocking” if you have made “diversity” into an ideological goal. Otherwise, it makes perfect sense that constantly engaging in politically correct diversity programs would make it harder for people to trust one another. Likewise, denying universal norms can’t help but promote individualism—destroying culture. Continued...