This is a citation of an outside article. Gravyday is not responsible for its content. Original URL below. We may know why younger brothers are more likely to be gay Having lots of boys can affect a woman’s immune response The more older brothers a boy has, the more likely he is to be gay when he grows up – an effect called the “fraternal birth order effect”. Now it seems that increasing levels of antibodies in a mother’s immune system could play a role.(more)
