Both.

The point should be made that the "abnormalities" consisted of the brains of homosexuals having certain characteristics of the opposite sex. Which is to say, male homosexuals' brains had certain characteristics of the female brain, the brains of lesbians showed some characteristics typical of the male brains.

I don't think brain scientists know yet whether these difference existed at birth or came later.

And whether they should be characterized as "abnormalities" is, perhaps, questionable.

Don Firth