OUR brains could be hard-wired to be male or female long before we begin to grow testes or ovaries in the womb. This discovery might explain why some people feel trapped in a body that’s the wrong sex, and could also lead to tests that reveal the true “brain sex” of babies born with ambiguous genitalia.
Till now, the orthodoxy among developmental biologists has been that embryos develop ovaries and become female unless a gene called SRY on the Y chromosome is switched on. If this gene is active, it makes testes develop instead. This switch is seen as the…
