Why are gays usually the youngest siblings?

Something something immune system response gets stronger every subsequent male child

Ask Blanchard, he's the one who figured that out.

What was Blanchard's proposed explanation? Was it that the woman's immune system does something to the fetus?

i think he didn't suggest a cause, as it was outside his field of study. however:
>In a 2017 study, researchers found an association between a maternal immune response to neuroligin 4 Y-linked protein (NLGN4Y) and subsequent sexual orientation in their sons. NLGN4Y is important in male brain development; the maternal immune reaction to it, in the form of anti-NLGN4Y antibodies, is thought to alter the brain structures underlying sexual orientation in the male fetus. The study found that women had significantly higher anti-NLGN4Y levels than men. The result also indicates that mothers of gay sons, particularly those with older brothers, had significantly higher anti-NLGN4Y levels than did the control samples of women, including mothers of heterosexual sons.[38]
-wikipedia

Blanchard? Isnt that what i do to spinach?

Thanks

im a gay guy and im the oldest soo

Nevermind, thats blanched greens

It's due to having an older mother. Klinefelter's and other conditions are increasingly common too.
Nothing to do with tons of older brothers. I don't know that long winded explanation is needed for the simpler one. I didn't know it was Blanchard who came up with it that explains why it's so retarded.

My mom had me when she was 36

pubmed.ncbi.nlm.nih.gov/29956083/#:~:text=The fraternal birth order effect,for androphilia in genotypic males.