How Are The Gay Younger Brothers Doing? - a podcast by Jeremiah

In the 1990s, Blanchard and Bogaert proposed the Fraternal Birth Order Effect (FBOE). Men with more older brothers were more likely to be gay. “The odds of having a gay son increase from approximately 2% for the first born son, to 3% for the second, 5% for the third and so on”.

https://www.astralcodexten.com/p/how-are-the-gay-younger-brothers