As long as I can remember, I've had books to read. Usually they'd be books my grandma had picked up on sale or at the used book shop, but I'd read just about anything I could get my hands on. This is how I discovered science fiction.
In fifth grade, I was at a new school. I didn't know anybody, and I've always had a spot of trouble making new friends, so I got books from the school library. I'd just gotten through the Wizard of Earthsea and its sequels, so I went to the next book by Ursula LeGuin on the shelf. It was The Left Hand of Darkness. Why that was in an elementary school library eludes me, but I read it then. I can say that I didn't get it when I was ten, but when I read it again at 25, it was clearer. LHoD examines a world where the people are agendered, but go into "kemmer" and develop secondary sexual characteristics for having sex. It isn't fixed which characteristics any person develops each time. The story explores an earth-human's interactions with the people of Gethen and their decision to join the ekumen, a league of worlds. It contains the remarkable line "the King is pregnant."
Aged ten, already ahead of my peers in science and math, and decidedly stubborn, it didn't mean too much. I didn't think much about it again until after I'd graduated from college. I'd picked it up, remembering that I'd liked it and the other books by her I'd read, and added it to the stack of books waiting to be read. Then I read it again. And it was groundbreaking. At the time it was written, the suggestion that there were no strict psychological differences between the sexes was a radical statement. Eliminating rigid gender roles -- including that of pregnancy -- was beyond radical.
In 1969 when it was originally published, no woman had won the Nebula for best novel. In 1968, a woman won best novella (Anne McCaffrey) and best short story (Kate Wilhelm), but Ursula LeGuin won best novel for 1969. Men continued to dominate, winning 8/10 in the 1970s and 7/10 in the 1980s, until the 1990s, when men and women each won 5 awards. This decade so far, winners have alternated between men and women. The winners for 2006 haven't yet been announced. (Nebulas are awarded by vote of members of the Science Fiction Writers Association.) Are there more female SF writers now? Or are they just more visible?
But it's so often the same women winning Nebulas or Hugos. Ursula LeGuin. C.J. Cherryh. Connie Willis. Anne McCaffrey. Lois McMaster Bujold. James Tiptree Jr. True, you often see the same men popping up year after year: David Brin, Asimov, Orson Scott Card, Kim Stanley Robinson. Is there an amount of favoritism? Certainly, because it's voted on by SF writers. All awards have that problem.
I took a peek at my bookshelf the other day. I have more books by CJ Cherryh than will fit onto one shelf, and it's still not her entire bibliography. I have every book Bujold has written. I have a lot of LeGuin. The only male author who has near the representation on my shelf is Terry Pratchett. I look at my husband's shelf, and (buried behind his action figures) are a lot of books by male authors: David Brin, Neal Stephenson, William Gibson, Card. He's got all the Neil Gaiman.
There is a trope that female readers prefer stories with good characterization, good plot, and good relationships, while male readers like a lot of sex and explosions and fancy sciency gadgets. I reject the notion of any inherent differences between male and female readers as to what their preferences are, but I can't resist exploring it.
Science fiction has long been "a man's world." As noted above, the majority of award-winning authors were male until recently, and male perspective characters are still predominant, even in books written by women. Take, for example, Bujold's Vorkosigan series. The main character, Miles Vorkosigan, is a man, as are a lot of leads: his father Aral, his cousin Ivan, his cousin Gregor, Gregor's security guy Simon. There are female leads, as well, and they're strong women: his mother Cordelia, her security woman Drou, the Koudelka clan (Drou's girls), Elli Quinn, who captains his mercenary fleet while he's home. But everything we see is from Miles' perspective. Or CJ Cherryh's Foreigner sequence (now up to 9 books). The main human is a man, and he has a male and female bodyguard (the latter of whom becomes his lover, naturally). The stories are told from Bren's perspective.
Conventional wisdom holds that people don't want to read stories about people who aren't like them. The main consumers of science fiction have traditionally been white males, so publishers go with books about white guys. Women are voracious consumers of science fiction now, and in participatory events (read: cons, fanzines, fanfiction), women participate with great enthusiasm. But it's still majority white, at least in the places I've been.
In stories written by female authors, you often have a focus on the characters, their development, and the plot, though some are marketed more to an action-oriented audience. Even then, you can follow character growth as the plot progresses and things blow up. Male authors, in my experience, focus on moving the story forward, in some cases to the detriment of character. It could be a function of good author vs bad, but I've found fewer bad female authors than male. This could be related to numbers, or to the idea that women have to be twice as good as the average man in order to be considered equal. (Or that women who have the spinal fortitude to break into science fiction are just damn good writers.)
Then there's the difference between "hard" and "soft" SF, and fantasy (which has a lot of female writers, and more non-traditional characters), which I won't get into here.
Part of the appeal of speculative fiction, which includes both science fiction and fantasy, is the ability to speculate. SF answers the question "what if?" Many of my favorite writers skip right past "what if women were equal to men?" and use that as a base assumption. On CJ Cherryh's starships, women do everything men do, even if the POV character is a man. LeGuin credits the feminist movement of the 1960s and 70s with helping her "learn to write as a woman, without putting men at the center of the story."
Subversive literature, indeed.