Are diversity and solidarity compatible?

Robert Putnam’s new work on diversity is sure to set the cat amongst the pigeons. The Boston Globe summarises the findings of The Bowling Alone author thus:

“the greater the diversity in a community, the fewer people vote and the less they volunteer, the less they give to charity and work on community projects. In the most diverse communities, neighbors trust one another about half as much as they do in the most homogenous settings.”

This research bolsters the argument that David Goodhart made a few years back about the tensions between ever-growing diversity and the welfare state. But I suspect that diversity is not actually at the root of these problems. Instead, we’re seeing a more fractured society thanks to family breakdown, longer working hours, greater internal migration and the like. Most of London, for example, wouldn’t be any more ‘cohesive’ if there were fewer immigrants.