Many people have argued that these changes have led to a culture of atomization, loneliness and self-absorption. That’s overdrawn. In “Going Solo,” Klinenberg nicely shows that people who live alone are more likely to visit friends and join social groups. They are more likely to congregate in and create active, dynamic cities.

It’s more accurate to say that we have gone from a society that protected people from their frailties to a society that allows people to maximize their talents.

The old settled social structures were stifling to many creative and dynamic people (and in those days discrimination stifled people even more). But people who were depressed, disorganized and disadvantaged were able to lead lives enmeshed in supportive relationships.

Today, the fast flexible and diverse networks allow the ambitious and the gifted to surf through amazing possibilities. They are able to construct richer, more varied lives. They are able to enjoy interesting information-age workplaces and then go home and find serenity in a one-bedroom apartment.

On the other hand, people who lack social capital are more likely to fall through the cracks. It takes effort, organization and a certain set of skills to surf these new, protean social networks. People who are unable to make the effort or lack social capital are more likely to be alone. As Klinenberg and others have shown, this is especially likely to happen to solitary middle-aged men, who are more likely to lack the drive and the social facilities to go out and make their own friendship circles.

Over all, we’ve made life richer for the people who have the social capital to create their own worlds. We’ve also made it harder for the people who don’t — especially poorer children.

These trends are not going to reverse themselves. So maybe it’s time to acknowledge a core reality: People with skills can really thrive in this tenuous, networked society. People without those advantages would probably be better off if we could build new versions of the settled, stable and thick arrangements we’ve left behind.