Colombia Law School manages a project that gathers peer-reviewed studies on the wellbeing of children with gay or lesbian parents. 77 studies dating to 1980 have been identified by project staff and experts at universities in the US and abroad. Of these studies, just four concluded that kids of same-sex parents face disadvantages, and these studies did not control for family stability, a factor known to affect kids’ outcomes.
A separate review of research from the University of Colorado Denver and the University of Oregon reached a similar conclusion. Analyzing 19,000 peer-reviewed studies and articles dating from 1977 to 2013, the researchers found that while there was disagreement on the effect of same-sex parenting in the 1980s, a consensus had formed by 2000 that there is no difference in psychological, behavioral, and educational outcomes between children of same-sex and different-sex parents.
Information gathered from The Boston Globe, “Children of same-sex parents fare as well as others, studies say“, Ami Albernaz, 2015