This year sees the 40th anniversary of the Stonewall riots, in which a club full of gay men fought back against the New York police sent to raid them. Thereby they founded the gay rights movement which evolved into the lesbian, gay, bisexual and transgender movement - or LGBT to its friends. The "L" comes first because, even in those early days of liberation and pride, it was obvious that the women were second-class citizens. If you're working to free an oppressed minority, it's not clever to create a sub-minority at the start.
The outer world, though, has been slow to catch on. Barack Obama introduced 176 "movers and shakers" of the LGBT movement invited to a 40th anniversary bash. Of them, a paltry 63 – that's 36 per cent - were women. The movement went postal. We know this is the equivalent of inviting "people of colour" and forgetting the Latinos, but I don't suppose Obama noticed, or particularly cared. His justice department, after all, issued a ruling likening homosexuality to incest and paedophilia; and, despite campaign promises, he's dragging his feet on repeal of the "Don't Ask, Don't Tell" policy in the armed forces. Plus ça change.
You might think the UK would be better but, when the Independent on Sunday published its list of the 101 "most influential gay men and women in Britain today", we had to scroll down to number five to find the first woman. That was Beth Ditto, an American, who apparently "exerts more influence over music, fashion and cool than many a politician". Because music, fashion and cool are vital to the welfare of the nation, and politicians are well-known for their influence over same? But writing isn't music, fashion and cool - and nobody seems to care about whether their gay icons are actively working towards gay equality, or are even gay.
Which is why it's all the more interesting to have been invited to this year's Theakstons Old Peculier Crime Writing Festival at Harrogate to take part tomorrow in a panel entitled "Dangerous Dykes". How cool is that? The UK crime-writing scene can pull together four disparate women (Val McDermid, Stella Duffy and Natasha Cooper are the other three panellists), all happy to contemplate the question of whether our sexuality is more of a bar to our progress than our gender. Although this is not what the subject is billed as, I suspect that's what it will turn out to be. The answer will be that, no, lesbian sexuality in the author or in the protagonist of a novel doesn't frighten the horses any more. But - sorry, girls - being a woman is still a bit of a downer when it comes to selling books.
This event could not have happened 40 years ago - or even 20 years ago, when McDermid's Lindsay Gordon jet-packed through the lavender ceiling of British crime writing and established the lesbian protagonist as a viable entity in the genre. For the first time, we had a lesbian woman writing about lesbian women for the mainstream, with plausible characters who were not obsessed about their sexuality.
It's hard for the straight world to get a handle on what life is like when you grow up without a single role model who is so secure in her sexuality that it doesn't matter any more. Where everybody knows and nobody really cares. This is where we want to get to. I don't know of a singe "lesbian" author who isn't heartily sick of the label and will continue to be until the world starts referring to everyone by their sexuality. On the other hand, as Stella Duffy says, "I do also want those 14-year-olds who are scared and shy and not yet out and have no access to a wider world to know that there are other possibilities out there, and I appreciate that my being called a 'lesbian writer' does sometimes give them a chance to find me, my work, others like me (like them)."
Which is the reason we do it - or part of it. Because we were all scared, lost 14-year-olds once, and we know how much it mattered to have something that normalised who we were.
We are everywhere now. But until McDermid's Report for Murder was published in 1987, every single work of "lesbian fiction" on my bookshelf had a plot that wholly or partially revolved around the protagonist's angst about her sexuality, the constant fear of being outed and, frequently, her hopeless love for a straight woman, doomed to heartbreak. Then McDermid proved to the risk-averse world of publishing that lesbian characters didn't hurt sales, and particularly not in a genre where the protagonists are, almost by definition, on the margins of society.
As she points out, "lesbians are particularly suited to the crime novel because the detective is both transgressive and discounted by society. And we don't actually have to do anything like drink too much or be emotionally screwed up to meet those criteria. We just have to be ourselves."
In the best of fiction, we can step beyond ourselves. The heroine in crime fiction is always a tad more daring than the rest of us; she takes more risks, she drives too fast, she hits people and gets away with it. Once in a while, she kills people and gets away with it. And she has sparky, interesting, acrobatic stranger-sex without (generally) falling into emotional meltdown afterwards. I never managed that.
Which is not to say that lesbian writers create one-dimensional characters. I would argue that the lesbian protagonist is frequently one of the most rounded characters in the genre. And I suspect – though I have no proof – that having a dyke in the mix might increase the male readership for women novelists above the paltry 20 per cent at which it is currently stuck.
Because that's the real issue in crime writing these days. Nobody bats an eyelid at gayness but, if you're a woman, then the overwhelming majority of your readership will be female. This has nothing to do with the nature of the crime.
Tess Gerritsen, Mo Hayder and Karin Slaughter, among others, are all writing what - to me - are astonishingly blood-soaked novels that sell by the shedload. There's a huge market for hard-bitten, emotionally broken women driving themselves to the edge of destruction in order to find a man who's killing women in a particularly sadistic manner. If you want to ring the changes in your blurring of the boundaries between snuff porn and fiction, Chelsea Cain has a female serial killer torturing men to death instead.
It doesn't change the sales figures. Whatever the content, most men do not knowingly buy books by women. Unless you have a gender-neutral name and your editor plans a carefully constructed gender-neutral biography, then your sales will be forever stuck at 80 per cent women, 20 per cent men.
Men do read crime novels. They also read crime novels that centre around lesbian characters. This year's must-read thrillers are the Millennium series by the late Stieg Larsson. Lisbeth Salander, his autistic, bisexual, computer-hacking, ultra-violent heroine, is one of the reasons they sell so well.
It's not even that men write emotionally illiterate novels and women don't. Andrew Taylor, Robert Wilson, Andrew Greig all grace my bookshelves, and all are in the top percentile for nuance, depth and intelligence. But I bet they don't suffer from the 80:20 split.
So, until we all either take up male pseudonyms, revert to our initials for identification or persuade men that we can write things they want to read without conning them into it, we are stuck in the dark ages. I'd like to think we won't have to wait another 40 years for the world to change, but I'm not holding my breath.
Manda Scott's 'The Crystal Skull' is published by Bantam