Over half-a-dozen medical groups, including the American Psychological Association, the American Medical Association and the American Academy of Pediatrics today filed an amici curiae brief supporting Karen Golinski's discrimination case against the government, Golinski v. Office of Personnel Management, which is requesting federal benefits for same-sex partners.
In their brief, a PDF of which I've included below, the good doctors offer scores of scientific data showing that same-sex parents do no hurt children, but that the government's prohibitions on marriage equality do.
From their introduction:
The claim that legal recognition of marriage for same–sex couples undermines the institution of marriage and harms their children is inconsistent with the scientific evidence. That evidence supports the conclusion that homosexuality is a normal expression of human sexuality that is not chosen; that gay and lesbian people form stable, committed relationships that are equivalent to heterosexual relationships in essential respects; and that same-sex couples are no less fit than heterosexual parents to raise children and their children are no less psychologically healthy and well-adjusted than children of opposite sex parents.