“I would argue that the rise of living alone represents the greatest social change of the last 60 years that we have failed to name or identify,” said NYU sociologist Eric Klinenberg. “This is a transformation that has touched all of us, whether we live alone or it’s just someone in our family or friendship circle who does.”

Klinenberg has spent years tracking the seismic spike in “solo dwelling.” He says today there are about 32.7 million Americans living alone. Clearly, if you live alone, you’re NOT alone.

“It’s an incredible number, and it’s a massive increase over where we were in 1950 when it was just four million Americans,” Klinenberg said.

One is no longer the loneliest number. Roughly four out of ten households are single-person homes, in cities like Seattle (42 percent), San Francisco (39.7 percent), Denver (40.4 percent), and Cleveland (39.9 percent).