As usual in developmental biology (:-)), it's nothing like as
straighforward as it seems.
However, it does seem that marked changes in behaviours that are often
thought of
as stereotypically sex linked in later life can be strongly influenced by
small changes
in hormone levels a a few very short (and very early) key stages of fetal
development.
The author was trained as a zoologist, but is better known as a
journalist and a former
editor of "The Economist". Worth a read, if perhaps not adding to the
Extropian canon.
His later work, "The Origin of Virtue", has interesting implications for
some libertarian
(and anti-liberatrian) arguments as well.
Bob.Grahame@mottmac.com