Americans are choosing to be alone. Here’s why we should reverse that.

The covid-19 pandemic wreaked havoc on our social lives. Cancellations, closures and fear of a potentially deadly infection led us to hunker down and avoid acquaintances, co-workers and extended family. Time spent with friends went down. Time spent alone went up.

Thanksgiving was not spared. Americans spent 38 percent less time with friends and extended family over the Thanksgiving weekend in the past two years than they had a decade prior.

And now for the scarier news: Our social lives were withering dramatically before covid-19. Between 2014 and 2019, time...