"Contrary to the cherished American notion that our racial and ethnic diversity makes us stronger, Putnam has found quite the opposite, at least in the short term. The greater the diversity in a community, the less civic engagement it shows, he says. Fewer people vote. Fewer volunteer. They give less to charity. They work together less on community projects. And they trust each other less, says Putnam, not only across racial and ethnic lines but also within the lines. In other words, residents of the most racially and ethnically mixed neighborhoods show the least trust not only of other races but also people of their own races. Does that mean people are better off living with, as the old racist mantra goes, "their own kind"? Or that we should impose a moratorium on immigration, as my column-writing colleague Pat Buchanan suggests in the piece that Duke touts? Not quite. In fact, in his first paper about his new research, "E Pluribus Unum: Diversity and Community in the 21st Century," Putnam says he wants to make three points perfectly clear: 1. "Increased immigration and diversity are not only inevitable" in modern societies, he writes, "but over the long run they are also desirable. Ethnic diversity is, on balance, an important social asset," as America's history demonstrates. 2. "In the short to medium run, however, immigration and ethnic diversity challenge social solidarity and inhibit social capital," he writes. "Social Capital" is the strength of relationships that bond you to people like you or "bridge" you to people who are different from you. 3. "In the medium to long run, on the other hand, successful immigrant societies create new forms of social solidarity and dampen the negative effects of diversity by constructing new, more encompassing identities," says Putnam. "Thus, the central challenge for modern, diversifying societies is to create a new, broader sense of 'we.' ""