In its historic decision legalizing same-sex marriage nationwide, the U.S. Supreme Court today cited research by Gary Gates, the Blachford-Cooper Distinguished Scholar and Research Director at the Williams Institute at UCLA School of Law.

“As all parties agree, many same-sex couples provide loving and nurturing homes to their children, whether biological or adopted. And hundreds of thousands of children are presently being raised by such couples,” the U.S. Supreme Court noted in its historic opinion, citing Gates’ studies and his amicus brief. “Most states have allowed gays and lesbians to adopt, either as individuals or as couples, and many adopted and foster children have same-sex parents,” the court held. “This provides powerful confirmation from the law itself that gays and lesbians can create loving, supportive families.”

Gates, director of research at the Williams Institute, which is part of the UCLA School of Law, filed an amicus brief in the landmark case in March.

“The story of marriage equality is also a story of the power of social science research to shape policy debates with facts rather than stereotypes or prejudices," Gates said in reaction to the historic ruling and the institute's part in it. "Williams Institute research documenting the demographic and economic characteristics of same-sex couples and their families played a key role in the debates about marriage equality and in educating the courts and the public about these couples and families. This is evident in Justice [Anthony M.] Kennedy’s words from today’s opinion ..."

Founded in 2001, the institute has become the country’s premier think tank on sexual orientation and gender identity law and public policy. It produces high-quality research with real-world relevance on sexual orientation and the law, then disseminates the research results to judges, legislators, policymakers, the media and the public.

According to research by the institute:

  • The number of married same-sex couples in the United States has tripled since 2013, to an estimated 390,000 couples.
  • An estimated 122,000 same-sex couples are raising 210,000 children under age 18, of whom 58,000 are adopted or foster children. Same-sex couples are nearly three times as likely as their different-sex counterparts to be raising an adopted or foster child.
  • Married same-sex couples are five times more likely to have these children than their different-sex counterparts. Married same-sex couples are more economically secure than unmarried.
  • Approximately 150,000 same-sex couples live in the 13 states that did not previously allow same-sex marriage. An estimated 70,000 of those couples will marry in the next three years.
  • Compared to all same-sex couples in the United States, those in the 13 states are more likely to have children, earn less and are more likely to be racial or ethnic minorities.
  • Public support for same-sex marriage has increased in all 50 states since 2004, especially in states that have legalized same-sex marriage.

The decision today legalizes marriage equality in the last 13 states that previously banned it — Arkansas, Georgia, Kentucky, Louisiana, Michigan, Mississippi, Missouri, Nebraska, North Dakota, Ohio, South Dakota, Tennessee and Texas.

In Kentucky, Michigan, Ohio and Tennessee, the states specifically at issue in the cases before the Supreme Court, 19 percent or nearly 11,000 of the 56,000 same-sex couples are raising more than 18,000 children under 18 years old.

Williams Institute scholars have filed amicus briefs and served as expert witnesses in many cases concerning marriage rights for same-sex couples, including all of the cases before the Supreme Court.  Numerous courts have relied explicitly on William Institute research in striking down bans on marriage for same-sex couples, including the U.S. Courts of Appeals for the Fourth, Seventh, and Ninth Circuits.

A webinar with Williams Institute legal and social science experts will be held at 8-9 a.m. on Monday, June 29, on the impact of this historic decision on children and families, stigma and LGBT health, public opinion, and state and local economies..

Williams Institute scholars are available for comment. To set up interviews or for more information about the webinar, contact Lauren Jow at or 310-206-0314.