This leads to differences in the brains of gay men which makes them gay. After every boy baby, the mother starts to develop an immunity to these male-specific antigens so will continue to release the hormones which may block full masculinisation of the brain. When she is pregnant with a boy, the baby releases male-specific antigens which stop the mother from releasing these anti-male hormones. When a mother is pregnant she releases anti-male hormones. This theory says that the more older brothers you have the more likely you are to be gay. Below are some of the reasons that biological psychologists believe I could be gay.ġ)Homosexuality is due to fraternal birth order. And as this is my first proper blog post, I thought it would be a perfect topic to explore.Įven within biological psychology there isn’t one single answer. Ever since I first came out there has been one question on my mind, Why am I gay?, and whilst there has been a tonne of research into this area, it seems that no one can agree on one single answer.