If unwed parents are going to get married, the best window of opportunity for that union seems to be before their child turns 3, says a new study from Duke University.
But patterns vary greatly by race, with more African-American mothers marrying much later than mothers of other races or ethnicities.
Federal policies have often presumed that unmarried parents will be most receptive to marriage right after a baby's birth, a period that has been dubbed the "magic moment." The new study is the first to test that assumption, said author Christina Gibson-Davis.
"It turns out the 'magic moment' lasts longer than conventional wisdom has held," said Gibson-Davis, who teaches sociology at Duke's Sanford School of Public Policy and is a faculty fellow of the Duke Center for Child and Family Policy. "And for some subgroups, that moment lasts even longer."
Among African-American mothers, most marriages occurred after the child turned 3, says the study, which appears online July 2 in Demography.
The study also found that most children born out of wedlock don't remain so: 64 percent of children born out of wedlock see their moms get married, Gibson-Davis said. Many of those marriages don't last, however. Nearly half of post-conception marriages end in divorce, and those numbers are higher still for African-American women.
"These marriages are fragile," Gibson-Davis said. "If you think that stable marriage is beneficial for kids, very few kids born out of wedlock are experiencing that."
The odds improve somewhat when mothers marry their child's biological father, Gibson-Davis said. After 10 years, 38 percent of post-conception marriages involving biological parents had dissolved. In the same period of time, 54 percent of marriages to a stepfather had ended. Those findings held true across racial lines.
The study draws upon a nationally representative survey that looks at 5,255 U.S. children born out of wedlock.
Despite years of public attention to children born out of wedlock, big gaps remain in our picture of how these children actually live, Gibson-Davis said.
"Those who would promote marriage have more work to do," Gibson-Davis said.
Explore further: Kids of single moms who later marry reap few benefits
"Magic Moment? Maternal Marriage in Children Born out of Wedlock," Christina Gibson-Davis. Demography, July 2, 2014. DOI: 10.1007/s13524-014-0308-7