Family structure has changed drastically for millions of American kids as one-fourth of the parents with whom they live are unmarried. That's well above the 7 percent who weren't married a half-century ago when the Current Population Survey started keeping track.
According to a new analysis by the Pew Research Center, 24 million American kids — nearly a third — live with unmarried parents.
The differences in household structure are so deep they have reshaped the words used to describe them. Unmarried parents without partners are now called "solo" mothers and fathers to distinguish between raising children with no partner and having a partner one didn't marry. Cohabiters make up 35 percent of all unmarried parents today.
In 1968 when the survey data was first collected, the bulk of unmarried parents were moms raising their children without a partner — and many people disapproved then and disapprove still, despite slight gains in acceptance.
What else hasn't changed significantly over the past 50 years? Despite the growth in sheer numbers of cohabiting households, they are still less stable for the kids growing up in them than married households, says Gretchen Livingston, a senior researcher for Pew who wrote the report.
Other experts agree.
"Prominent family scholars have said they are worried about the kids," said Brian J. Willoughby, as associate professor of family life at Brigham Young University. "The worry is instabilty. … Kids are moving a lot, going back and forth between mom's and dad's house."
On the one hand, children in solo-mother households are more likely to live in poverty than households with two parents, married or not, as both are more likely to be wage earners.
On the other hand, it's common for cohabiting households to break up after five to seven years, Willoughby said. And for the kids, the outcomes look like what happens in divorce.
The Pew report cites an estimate by Demographic Research that by age 9, more than half of those born to cohabiting couples will see their parents break up compared to one-fifth of U.S. kids who were born to married parents. That often kicks off a cycle of different cohabiting relationships and breakups and more divorce, both of which increase instability for kids.
Cohabiting relationships are "less long-lasting than marriages," the report said.
The increase in unmarried parenthood reflects several factors, including fewer couples marrying, those who do marry are typically older than in the past and a long-term increase trend and the fact that marriages are more likely to end in divorce than they were decades ago, a fact to which Willoughby says the expectation of romantic love has contributed. In the past, partnership factors could hold a marriage together, with or without romance.
Pew drills down on the numbers:
— In 2017, the median age of first marriage was 27 for women and 30 for men, compared to 21 and 23, respectively, in 1968.
— Meanwhile, divorce is much more a fact of life than it was 50 years ago. Pew said 76 percent of men in first marriages that began in the late '80s were still wed after a decade. That share was considerably larger, 88 percent, for marriages that were launched in the 1950s.
The differences between typical households of each type of unmarried parent are quite distinctive, according to Livingston. Cohabiting parents tend to have less education and be younger and their children are typically younger, too. Cohabiters are less likely to have ever been married, compared to solo parents. Cohabiters are typically raising more children and they're probably not living with one of their parents, which is more common among solo parents. Of solo parents, 81 percent are female, while the split on cohabiting parents — most of whom are heterosexual couples — is about even.
Subgroups vary, as well. For example, the families of solo moms are more likely to live in poverty than those of solo dads, who more resemble, at least financially, households headed by cohabiting parents.
"The difference in poverty rates is definitely very interesting," according to Livingston. She said about 17 percent of solo dads live in poverty, compared to 30 percent of solo moms. One factor could be that solo moms are more likely than solo dads to have more than one child at home and to have younger children. And more solo dads live with one or more of their parents, who may contribute financially or help with child care.
It is not clear whether the solo parents are moving in with their parents or their parents are moving in, she added. But it's much rarer — only about 4 percent — for cohabiting or married parents to live with their parents.
There's another change, too: Cohabiters in other decades were often "people kind of testing the water before marriage. Cohabitation is a lot of subcategories now," Willoughby said, including those who don't ever intend to get married.
For the kids and for stability, the cohabiters most likely to go the distance are those who have clear plans to marry in the future. "They have more stability that other cohabiters don't have," Willoughby said.
Despite the fact it's more and more common and some may be more accepting than in the past, a large portion of those surveyed said unmarried parenthood isn't good for society.
Solo motherhood has been viewed as the least favorable family structure.
In a 2015 Pew survey, researchers found two-thirds of adults called more women raising kids solo "bad for society," compared to 48 percent who said that about unmarried couples.
"It's striking," Livingston said. "Among the things we asked about, those were by far the trends that met with the most disapproval. To put that in perspective, about 40 percent say more children who have parents who are gay or lesbian are bad for society. The numbers go down from there. ... It's an interesting frame of reference that on the one hand, there's been a vast increase in the number of families who are unmarried-parent families and we have seen a slight uptick in acceptance generally, but at the same time a majority are often disapproving of these situations."
The most recent American Family Survey, conducted by YouGov, also documented significant concern about single parenthood: 28 percent of respondents said that "more children being raised in single-parent homes" was the greatest challenge facing the American family.
Any increase in solo moms having kids is especially unpopular among Republicans, whites and college grads, the report says, although in a 2012 General Social Survey nearly half of those polled conceded that a single parent could do as good a job parenting as two married parents. The Pew report finds interracial marriage and more children with parents of different races "doesn't make much of a difference for society."