In a switch that highlights enormous changes in the American family, married couples no longer make up the majority of households in the Twin Cities area.

A new release of 2010 state data by the U.S. Census Bureau on Thursday shows that 48.6 percent of households in the seven-county metropolitan area were married couples. That's down from 50.9 percent in 2000. The rest of Minnesota is not far behind, with 50.8 percent of households made up of married couples.

"We've been going through a long period of social change," state Demographer Tom Gillaspy said. "Families with kids are no longer the largest single family type, and many couples are not together by contract. ... Changing families are one of the big issues we will face in the next couple of decades."

The proportion of married households in the nation has been dropping since 1950, when 78 percent of households were married couples. By 2000, that had dropped to 52 percent.

"People do value marriage, but it's more like an ideal, not a necessity," said Bill Doherty, University of Minnesota family and social science professor. Polls show that young Americans overwhelmingly want to get married. But people are waiting longer to tie the knot, and many don't feel the need to get married.

"You don't have to be married to be seen as an adult now," Doherty said. "Before, a 30-something unmarried guy was passed over for a management position, and a 30-something unmarried woman was a spinster who was seen as living a depleted life.

"Now we have a lot more opportunity and cultural permission for people to live big parts of their adult life outside of marriage."

Pam Riegel, 29, and Dax Flyger, 34, have been together for three years and are looking at buying a house. They've talked about getting married but are waiting until they're more settled, Riegel said.

"We're young," she said. "I'm getting my career started, and he was out of work and is getting back into the workforce. I never felt I had to get married by a certain time."

Justin Berndt and Jessica Nickrand also have talked about tying the knot. But Berndt, 25, said the thought of planning a wedding while Nickrand, 23, is focused on earning a Ph.D just seemed like too much.

"It's not a commitment issue so much as a time issue," Berndt said. "Maybe it's a generational thing. We're living together, this is working now, why step on it? We really care about each other.

"We'll go at our own speed, and when life is at a different place we'll look at it."

College-educated people still marry in large numbers, Doherty said, making marriage strong among the middle class. That shows in the census results. Counties that ring the Twin Cities -- Scott, Carver, Sherburne, Wright and Washington -- along with Dodge County in southeastern Minnesota have the highest proportion of married households in the state, at more than 60 percent. Hennepin and Ramsey counties are in the bottom three in Minnesota, at 43 and 41 percent respectively.

Among cities, wealthier suburbs such as Sunfish Lake, Victoria, Minnetrista, Medina and North Oaks have close to 75 percent of households made up of married couples. In Minneapolis that figure is 28 percent. About 43 percent of Minneapolis households are made up of people living alone.

Some experts worry that the decline of marriage, especially among lower-income people, creates instability for children and loosens ties between generations. Studies show that married fathers are most involved in child-rearing, Doherty said.

"We have more adult freedom ... but there's no way to view this as good for children," he said.

For more data, see the Census 2010 Interactive Population Map.

Mary Jane Smetanka • 612-673-7380