The influence comes not from one gene but many, each with a tiny effect — and the rest of the explanation includes social or environmental factors — making it impossible to use genes to predict someone’s sexuality.
2019 marks the 50th anniversary of the Stonewall riots. The Gay Liberation Front chose June to be pride month in commemoration of Stonewall. During this time of year, due to the commemoration, people often say that Stonewall was the first action of modern gay liberation. However, this isn’t entirely true. It kickstarted much of the modern American gay rights movement. But even in the US action groups like The Daughters of Bilitis and The Mattachine Society fought for gay rights a decade before Stonewall. Worldwide though, the modern gay liberation movement originated in Berlin with the action of Magnus Hirschfeld and his organization, the Scientific Humanitarian Committee.