Celibacy among girls seems to be up a bit: Agnostic has an interesting post at Gene Expression which presents evidence that previous generations of young people were sluttier than this one.
It has seemed the case that many social indicators have at least plateaued, if not improved slightly since the early 90s, but increasingly coarse pop culture does give older people the impression of a continuing slide.
For example, phenomena like Jackass or Eminem leave one with a sense that the march toward the next, even more shocking fad continues apace. One mistake is to assume that young people are what they seem to older people. Fashion always involves a certain amount of the absurd, and once you move out of those years when it's so important to impress peers, one becomes more disinterested, and many fashions then just seem stupid. "Wearing your pants down below your butt? Idiotic. Only a delinquent would do something that irrational. Wearing a thong that everyone sees? Slutty. Only a girl who sleeps with anyone would do that."
What older folks fail to realize is that fashion--even when it seems extreme--is ultimately about show, and is a poor indicator of behavior. I've got a friend who was a headbanger as a teen. He looked like a two-time felon, and all the grownups at the mall were terrified of him. But I've never known a bigger pussycat--it was all pose, and it usually is.
That's what so great about data--it gets past appearances. Which is a nice segue to my purpose--analyzing General Social Survey data to document trends in sluttiness. I list below the percent of males and females ages 18-25 who report having had 5+ sex partners so far, and the percent who have remained celibate:
Percent--1988-1991 average (N = 624)
Percent--1993-1998 average (N = 1009)
Percent--2000-2006 average (N = 1,133)
I'm not surprised to see what basically looks like a plateau, but one encouraging sign is that the number of girls who are remaining celibate appears to be up. I'm damn happy to see it.
By the way, I'm a bit of a cultural declinist, but Agnostic and other young bloggers I've read seem to be targeting Boomers and X-ers. My reference--and for a lot of thoughtful declinists, I think--is not any of the last four decades. It's WWII through the late 50s. I see a steady decline (with important exceptions) since then, with a flattening more recently. (This is a complicated question, of course, since there are so many trends one could choose to look at).
The only reason why I have a little bit of nostalgia--not much--for my childhood and adolescence is because I was raised in a place that was decades behind every place else. In other words, it was a bit like the 50s. It's easy for me to wax nostalgic as people much older than I (Pat Buchanan for example) do because in a weird way I grew up in that.