(CBS)-- NO MAN IS AN ISLAND ... or so poet John Donne wrote nearly four centuries ago. What would he think if he could come back and see the isolated way so many of us live now? Here's Susan Spencer of "48 Hours":
For Greta Garbo, solitude was a mantra; for Henry David Thoreau, an ideal; for Howard Hughes, an obsession.
But for more and more Americans today, it's just reality.
"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).
And then there's Manhattan, an urban island where almost HALF of all households are made up of just one person - where millions of people seek safe harbor tonight in an empty apartment.
Does that sound lonely to YOU? Well, don't tell THEM that.
New Yorker Kate Bolic wrote a popular Atlantic article about the joys of living alone.
"I like being able to control my time on my own terms," said New Yorker Kate Bolick. "I like that I can eat when I want, read when I want, see friends when I want to. I like that I don't have to make compromises in the way I spend time."
Bolick could be the poster child for the new American family . . . a family of one. Not even a cat to feed. "And you're not lonely?" asked Spencer.
Now 39, Bolick turned solitude into celebrity. Her 2011 article on living alone was one of the most widely-read pieces in The Atlantic's history. It netted her a major book deal, and even was optioned for a TV series.
"I grew up very close with my family, and I'd always had long-term boyfriends, roommates," Bolick said. "I thought, 'God, you know, who am I on my own when I'm not being supported by these people who love me?'"
"You almost make this sound like it was a test," said Spencer.
"Oh, that's a good way of putting it," she laughed. "I think it kind of was."
She aced that test. And sociologist Klinenberg says she should be proud. He calls single people "indispensible."
"They go out into the world like no one else does and spend time and money in bars and restaurants, in cafes, in gyms, in clubs," he said. "They're the ones who are most likely to go to public events - book readings, art classes, all kinds of public activities that give life to city streets."
So who are these wonderful people? Well, one-third (34.5 percent) are 65 or over, and about half (48.3 percent) are between 35 and 64.
And the women (17.2 million) outnumber the men (13.9 million).