And so liberals envisage diverse communities which express communal solidarity: diversity is our strength is the liberal mantra.
Some years ago Professor Robert Putnam of Harvard University cast doubt on the liberal project when he discovered that diversity and solidarity don't go well together:
The evidence that diversity and solidarity are negatively correlated comes from many different settings.
Professor Putnam found that there was less trust in highly diverse communities and that individuals tended to "hunker down" in such communities:
Diversity does not produce ‘bad race relations’ or ethnically-defined group hostility, our findings suggest. Rather, inhabitants of diverse communities tend to withdraw from collective life, to distrust their neighbours, regardless of the colour of their skin, to withdraw even from close friends, to expect the worst from their community and its leaders, to volunteer less, give less to charity and work on community projects less often, to register to vote less, to agitate for social reform more, but have less faith that they can actually make a difference, and to huddle unhappily in front of the television.
Now another important research project has come to similar conclusions. Two researchers from the University of Michigan, Zachary Neal and Jennifer Watling Neal, decided to test whether it was possible to build diverse and cohesive communities.
The answer? A clear no:
After 20 million-plus simulations, the authors found that the same basic answer kept coming back: The more diverse or integrated a neighborhood is, the less socially cohesive it becomes, while the more homogenous or segregated it is, the more socially cohesive.
Their simulations of more than 20 million virtual “neighborhoods” demonstrate a troubling paradox: that community and diversity may be fundamentally incompatible goals. As the authors explain, integration “provides opportunities for intergroup contact that are necessary to promote respect for diversity, but may prevent the formation of dense interpersonal networks that are necessary to promote sense of community.”
These findings are sobering. Because homophily and proximity are so ingrained in the way humans interact, the models demonstrated that it was impossible to simultaneously foster diversity and cohesion “in all reasonably likely worlds.” In fact, the trends are so strong that no effective social policy could combat them, according to Neal. As he put it in a statement, “In essence, when it comes to neighborhood desegregation and social cohesion, you can't have your cake and eat it too.”
In brief, these researchers are now convinced that you can either have diversity (desegregation) or social cohesion. One or the other.
The journalist covering the story suggested to the researchers that it might still be possible to have diversity at a city level rather than a neighbourhood one:
On a more positive note, it may be possible to have such sorting by neighborhoods and still have diverse cities. I asked Neal whether he thought that cities that were made up of a federation or mosaic of distinct neighborhoods were more likely to succeed than ones comprised of several more fully mixed neighborhoods.
That would, at least, give some room for distinct communities to exist. The traditionalist ideal, however, is to enact the same principle at a global level, in other words, to enjoy the diversity of distinct national cultures. It's more realistic to have cultures maintain themselves at the national level rather than a neighbourhood one.
However, credit to the researchers and to the journalist for accepting the scientific findings that you build community (solidarity) on the basis of like qualities or relatedness (homophily) rather than on diversity. Right now, getting the underlying principle right is what is most important.
One final point. In traditional communities, in which solidarity is based on forms of relatedness, there is still a diversity of sorts. Such communities have a deep sense of solidarity but there is still diversity based on distinct class and regional cultures. That remains the best way to reconcile the enjoyment of both diversity and community.