In the late 1970s, queer parents increasingly fought to maintain custody of their children from different-sex relationships. These mothers and fathers were responding in part to the gay liberation movement, which inspired them to come out and demand their rights. Also important was that the American Psychiatric Association declassified homosexuality as a mental illness, which eliminated what had been an all-but-impenetrable barrier to custody. Courts were nevertheless reluctant to grant these petitions, fearing that the children would learn to be gay or lesbian from the adults in their lives. In response to these court cases, social scientists developed research studies that concluded parental homosexuality had no effect on the future sexual orientation of children. Based on that work, family courts around the country granted custody to lesbian mothers and gay fathers in the late 1970s and early 1980s, creating the first wave of visible queer-headed families.