Notice how the word "male" is only mentioned in this article as an adjective ("male/female mix", "male/female interests"), but "females" is often used as a synonym for "women" ("% of females", "people likely to trust females", "females in career", "likes from females"). "Female" is not a drop-in replacement for "women".
> Using "female" in this way is contrary to how we generally communicate. As noted above, "female" as a noun erases the subject—making "female" the subject of the sentence. In the most technical sense, it's correct, but by employing this word that is usually an adjective as a noun, you're reducing her whole personhood to the confines of that adjective. It's calling someone "a white" instead of a white person, "a black" instead of a black person, and so on.[0]
Not really trying to judge this article—it's been a while since I've dealt with research jargon, and I can't judge whether referring to groups as adjectives like this is standard practice in that field. And the Jezebel article I've linked to even mentions that "females" has a clinical feel, so I wouldn't be surprised if it's standard in this setting. But this bias is pretty prevalent in everyday speech and is worth being aware of and trying to prevent.
[0]: http://jezebel.com/the-problem-with-calling-women-females-16...