Dr. Travis Kidner, who is in a same-sex marriage, with his children Zoe (being carried) and Nicholas in Los Angeles on Wednesday
The academy's new policy statement says same-sex marriage helps guarantee rights, benefits and long-term security for children, while acknowledging that it does not now ensure access to federal benefits. When marriage is not an option, the academy said, children should not be deprived of foster care or adoption by single parents or couples, whatever their sexual orientation.
The academy's review of scientific literature began more than four years ago, and the result is a 10-page report with 60 citations.
"If the studies are different in their design and sample but the results continue to be similar, that gives scientists and consumers more faith in the result," said Dr. Ellen Perrin, a co-author of the new policy and a professor of pediatrics at Tufts University School of Medicine.
Other scientists called the evidence lackluster and said the academy's endorsement was premature. Loren Marks, an associate professor of child and family studies at Louisiana State University in Baton Rouge, said there was not enough national data to support the pediatric association's position on same-sex marriage. "National policy should be informed by nationally representative data," he said. "We are moving in the direction of higher-quality national data, but it's slow."
The academy cited research finding that a child's well-being is much more affected by the strength of relationships among family members and a family's social and economic resources than by the sexual orientation of the parents. "There is an emerging consensus, based on extensive review of the scientific literature, that children growing up in households headed by gay men or lesbians are not disadvantaged in any significant respect relative to children of heterosexual parents," the academy said.
A large body of evidence demonstrates that children raised by gay or lesbian parents fare as well in emotional, cognitive and social functioning as peers raised by heterosexuals, the academy said.
One study in England compared 39 families with lesbian mothers to 74 heterosexual parents and 60 families headed by single heterosexual women. No difference was found between the groups in emotional involvement, abnormal behaviors in children as reported by parents or teachers, or psychiatric disorders in them. Both mothers and teachers reported more behavioral problems among children in single-parent families than two-parent ones, whatever their sexual orientation.
A 2010 study of children born to 154 lesbian parents in the United States compared mothers' reports of their 17-year-olds to a national sample of age-matched peers. The mothers' reports indicated that their sons and daughters had high levels of competence and fewer social problems, compared with their peers.
"Marriage strengthens families and benefits child development, and it also increases a parent's sense of competence and security when they are able to raise children without stigma," said Dr. Nanette Gartrell, the lead author of the study and a visiting scholar at the University of California, Los Angeles, School of Law.
The research on same-sex marriage has limitations, experts note, including the relatively small sample sizes of gay or lesbian parents even in long-term studies. Many studies have relied on parental assessments of their children's well-being, and there is relatively little data about the well-being of children raised by gay men compared with lesbians.
"Many studies compare wealthy, well-educated lesbian mothers to single heterosexual mothers instead of married couples," Dr. Marks said. "This matters, because children from married families do better on numerous outcomes including psychological and physical health and avoidance of high-risk behaviors than children of single-parent families."
Timm Ryan-Young, a 48-year-old married Brooklynite and father of Zelia, 6, found the academy's support of same-sex marriage reaffirming.
"Whenever a formal institution validates or confirms that a same-sex family is valid," he said, "and there are no measurable negatives to it, or deterrents to it, it means a great deal, frankly."
Dr. Travis Kidner, 36, a surgeon in Los Angeles, and Hernan Lopez, 42, a media executive, married in 2008 and adopted Nicholas, 2 1/2 years old, and Zoe, 21 months. "It's important for kids to know they are from a stable home and that their parents are married," Dr. Kidner said.
The pediatrics academy's support for same-sex marriage heartened him. "The arc is in our favor now," he said.
Another reason same-sex couples should be allowed to marry, the academy said, is that divorce law provides for a legally structured arrangement for visits and custody.
"If people can't get married, then they can't get divorced," Dr. Perrin said. "That legal system that exists to protect our most vulnerable, namely children, isn't in play."