The awesome blog Towleroad put together a great post about the American Psychological Association, the American Medical Association, as well as other organizations, and the amicus brief that was filed in the case against DoMA, the egregious “Defense of Marriage Act” passed by the Congress and signed into law by Bill Clinton on the 1990s.
Go read the article, which includes scientific proof that gays and lesbians enjoy the same relationships as their heterosexual counterparts, as well as showing their children aren’t harmed by same-sex parents, but are harmed by laws like DoMA.