What is the origin of homosexuality? Are we born gay or do we become gay? Why does the very fact of asking the question provoke so much debate? Ted Anspach investigated in Europe and the United States. On December 7, 2004, Christian Vanneste, a UMP deputy, caused a scandal in the National Assembly by making homophobic remarks. Despite his recent condemnation, he reiterates here: "Homosexuality is a threat (...) Parents should be offered treatment when homosexual tendencies are detected in their child." To these unacceptable remarks this film opposes the very personal testimonies of homosexuals. There is Skander, a Frenchman of North African origin, who explains how he felt gay from a very young age, despite family pressure. And also Monique and Isabelle, a lesbian couple who "revealed themselves" after many years of heterosexual life.The investigation continues in the United States, where the debate on the origin of homosexuality is raging.