Excellent point, Laura. I've often thought about that, too.
This came up earlier here at BetterMost, in discussions of strangers having sex in public places, such as restrooms. Obviously, it's something that some men do from time to time. Again, I don't have statistics handy, but I'm guessing it's very, very unusual for women (aside from prostitutes) to have quick casual sex with someone they have never spoken to and know absolutely nothing about.
Katherine, I would say that there are forces far different than biology involved here; it is a cultural standard for the dominant sex - for there is no doubt that the US is a patriarchal society - to determine the modes of sexual behavior, and this has been true since the rise of patriarchal cultures based in classical Greece and Rome. Men had a privileged role as citizens in classical society, and the noble class had free access to slaves and citizens of both sexes to enjoy, and lacking the stigma against same sex relations, indulged in both, whereas women had very strictly defined sex and labor roles as caretakers, housekeepers and cooks, and could not be citizens. In the US today the 'modern' 'socialist' innovations of 'parental leave' which extends to both husbands and wives is derided in the US as relegating husbands to caretaking roles they should not "have to do." Only in America is there such a term as "Mr. Mom," because parenting is seen as a domestic duty of the chattel female who must bear and care for children. Europe is way ahead in terms of sharing parenting in families, equalizing professional roles, and removing stigmas that relegate women to a narrow range of behavior. Accordingly, you will see a very different type of demographic for dating and public sexual behavior in those cultures because the emphasis is changing - socially speaking, Europe is at least 100 years ahead of the US (that is my completely made-up statistic based on personal observation.)
I also think that those of us (females) who have been either "reared male" (not to take on a traditional marriage-and-childbearing role, but a career role), or educated outside the home to non-traditionally-female adult roles or professions, tend not to see that their experience is atypical for America as a whole.
For that matter, how many women -- as opposed to men -- hire prostitutes? I would guess there are far, far more prostitutes of either gender catering to men than there are for women.
different manifestation of the same cultural predilection.
Another sign of difference: the number of male rapists and molesters vs. the much lower number of female rapists and molesters. Not that rape is all about sex -- there's a violence aspect, too, and women tend to commit fewer violent crimes of all kinds. Other factors may include physical strength, the physiology of arousal, etc. Still, it's telling that female perpetrators are so uncommon -- again, not nonexistent, but relatively rare.
If men and women were indistinguishable in terms of their appetite for casual, no-strings sex, they'd be equally involved with all that stuff.
The difference here, I would concur, may be related to biology, but the rise in violent crime perpetrated by women, including child molestation and rap,e shows that things are changing - and biology doesn't change that fast. However - culture does. Most rape of males by females is by female adults with male children or adolescents, however, I have been involved in the prosecution process as a witness against a female perpetrator against her daughter. The D.A. refused to press a sexual assault charge, desptie physical evidence. His reason was blunt: "no one would believe a mother would do that to her daughter." He's right, too: a jury wouldn't convict a woman of molesting her daughter, because they deny it happens. Also, according to the dictates of the strict sex roles of this society: boys, adolescent males and men are acculturated to treat unwanted sexual contact from females as flattering, and not as abuse. There have been a few high-profile instances of sexual abuse of girls by women, possibly the highest profile one was at Oprah's south African school, where female staff members were abusing the schoolgirls. It happens: but people dont' talk about it. It's not biology at work here.