NEW YORK A s a 20-something, Erin Turner feels she made all the right moves dating wise. She graduated from college and spent three and a half years with a boyfriend before they moved in together.

Their cohabitation bliss lasted only eight months.

“We broke up because when you live with someone, everything comes to the surface,” said Turner, who remains single in Chicago as her 30th birthday approaches in March.

“You start to see how people handle confrontation, financial realities, challenges, the housework load. If we had been married we would have been divorced, or fully on our way.”

While Turner hopes to marry one day, she’s not sweating it at the moment. Her parents divorced when she was young and she doesn’t want marriage badly enough to settle. She’d be sad if she never married, but she wouldn’t “implode.”

Heading into 2012, trend watchers note that barely half of all adults in the United States are married, and the median age at the time of a first marriage has never been higher — slightly more than 26 years old for women and nearly 29 for men.

In 1960, 72 percent of adults 18 and older were married. The percentage fell to 57 percent in 2000 and today it’s just 51 percent, according to a new Pew Research Center analysis of census data.

The share of marrieds could dip below half in a few years as singleperson households, single parents and couples living together outside the bounds of legal marriage multiply. The number of new marriages in the U.S. fell 5 percent just from 2009 to 2010, a wrinkle that may or may not relate to the bad economy, Pew researcher D’Vera Cohn said.

The decline is spread among age groups but is most dramatic among Turner’s generation. Nearly three out of every five adults ages 18 to 29 were married in 1960, but now only one in five is.

Marriage also is on the decline in other developed countries, especially those in Europe, and the trend is starting to take root elsewhere around the globe.

In Mexico City, for instance, a recent proposal would allow couples to “test drive” marriage with a twoyear contract, said Ann Mack, a trend watcher for JWT Intelligence, an arm of the marketing giant. If the trial marriage didn’t work out, the parties could walk away without lengthy divorce proceedings.

Women, in particular, are experiencing a mass marriage rethink, Mack said. “A growing number of women are taking an alternate life route that doesn’t include marriage as an essential checkpoint,” she said.

Retreat, maybe. But not outright abandonment, said Cohn and Stephanie Coontz, who wrote “Marriage: A History” and teaches family studies at Evergreen State University in Olympia, Wash.

“We as a society have to recognize that people do still get married but cycle into marriage later and may cycle out of marriage,” she said. “I think marriage is perceived as a very desirable good but no longer a necessity.”

In New York, 30-year-old Grace Bello loves kids. Her mom was 30 when she gave birth to her, but Bello didn’t have the American dream of a picket fence, husband and 2.5 children in her head growing up in Cupertino, Calif. She recently broke up with a guy she had been dating casually for a few weeks and is busily pursuing a freelance writing career.

“Not getting married wouldn’t be the worst thing in the world,” Bello said. “I think the worst-case scenario would be a loveless marriage that ends in divorce and to be a single mom supporting several kids. I’d rather be single for the rest of my life.”

There’s a lot to like about living single, said Bella DePaulo, who wrote the book “Singled Out.”

“We’re so used to, as a society, thinking about life in terms of what it means to be coupled and married that we miss out on all the ways in which living single has some real attractions, like having your own space,” said DePaulo, who at 58 is happily single herself.

Among the more dramatic developments is a 17-point marriage disparity along education lines.

Nearly two-thirds of all adults with college degrees, or 64 percent, are married, compared with 47 percent with high school degrees or less, according to the Pew snapshot released Dec. 14. Fifty years ago, college graduates and those who had not gone beyond high school were about equally likely to be married.

For less educated and lower earning women in particular, Coontz said marriage is riskier than it used to be.

“Men’s real wages have fallen and they face a lot of job insecurity, so a woman who would have found a high school graduate a pretty damn good catch in 1960 now has to say to herself, ‘Would it really be smart of me to marry this guy?’ She’s choosing to focus on her own earning power.”

A separate Pew survey released last year found that while nearly 40 percent of respondents said marriage is becoming obsolete, 61 percent of those who were not married would like to be someday.

“I need to support a future family,” said Vince Tornero, a 23-year-old senior at Ohio State University in Columbus. “I want to have kids but I can’t have kids if I don’t have money.”

Pew also found that marriage statistics vary by race, with 55 percent of whites, 48 percent of Hispanics but just 31 percent of blacks married.

“I thought I’d be married by now, honestly,” said Keisha Pickett, who is 31, black and single in Tampa, Fla. “In my circle of friends, they haven’t necessarily given up on it but they’re scared. You give it your all and it could all blow up in your face one day.”

Pickett is dating but has no special someone. “I had a honeybunch up until about four months ago. We had been back and forth for, like, three years,” she said. “It just came to a point where I felt like it was forced. I’m very outgoing and ambitious and he was kind of a complacent, in-thehouse guy.”

¦ IN 1960, 72 percent of all American adults 18 and older were married. The percentage fell to 57 percent in 2000 and today it’s just 51 percent, according to a new Pew Research Center analysis of census data.