Well, I think to some extent with sexual activity we can't assess really accurately, since a lot of people don't write about that. With my flist, I know a lot of people are married (and presumably having sex) and a lot more (especially the younger ones) are woeful about their inability to date for whatever reason. Since I am myself young, my flist skews towards the younger high school/college set, not the older married set as much (most of those I added because they were in the SCA or in my academic field; my personal journal only has the fannish people I consider friends).

I can't imagine answering most of the questions for the flist on my purely fannish LJ; I barely know who most of the people on it are, since I add back anyone who adds me who has intersecting interests.