http://www.livescience.com/27682-women-men-science-gender-gap.html
"Though women now receive half the doctorates in science and engineering in the United States, they make up only 21 percent of full science professors and a measly 5 percent of full engineering professors."
If women aren't becoming scientists, that's their own fault. Nothing is holding them back, and scholarships are even going out of their way to give preference to women.
Actually I didn't imply that there was anything holding them back. I was just making a meme. However, the link I posted and quoted from in response to another imgflipper above does imply that. So, I don't know.