Lynn, I know exactly what you are referring to.  I also read about this before with great interest because I have a daughter with CAH.  It certainly explained why she was not so interested in dolls, dressing up, etc when younger.  She preferred the "boy's" toys - like cars and trucks and could outbuild anyone with Legos when she was only about 3!  Her skills and interest in math and science are more like boys her age than girls - and she is fascinated with the mechanics of how things work.  I know this may not apply to ALL CAH girls, but I have seen from other messages on the board that it is not uncommon - and what I have read is that in utero when the mother is not taking dex, the excess testerone being produced in the baby girl affects the way her brain develops, causing it to develop more like a male.  It is the same hormone that affects the development of the genitalia.  It stands to reason, to me, that if the excess hormone can produce such dramatic external effect, it could/would also affect the brain in its development.